1
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Ousingsawat J, Schreiber R, Kunzelmann K. Functional Interdependence of Anoctamins May Influence Conclusions from Overexpression Studies. Int J Mol Sci 2024; 25:9998. [PMID: 39337485 PMCID: PMC11432102 DOI: 10.3390/ijms25189998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2024] [Revised: 09/09/2024] [Accepted: 09/15/2024] [Indexed: 09/30/2024] Open
Abstract
Anoctamin 6 (ANO6, TMEM16F) is a phospholipid (PL) scramblase that moves PLs between both plasma membrane (PM) leaflets and operates as an ion channel. It plays a role in development and is essential for hemostasis, bone mineralization and immune defense. However, ANO6 has also been shown to regulate cellular Ca2+ signaling and PM compartments, thereby controlling the expression of ion channels such as CFTR. Given these pleiotropic effects, we investigated the functional interdependence of the ubiquitous ANO6 with other commonly co-expressed anoctamins. As most expression studies on anoctamins use HEK293 human embryonic kidney cells, we compared ion currents, PL scrambling and Ca2+ signals induced by the overexpression of anoctamins in HEK293 wild-type parental and ANO6-knockout cells. The data suggest that the endogenous expression of ANO6 significantly affects the results obtained from overexpressed anoctamins, particularly after increasing intracellular Ca2+. Thus, a significant interdependence of anoctamins may influence the interpretation of data obtained from the functional analysis of overexpressed anoctamins.
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Affiliation(s)
| | | | - Karl Kunzelmann
- Physiological Institute, University of Regensburg, University Street 31, D-93053 Regensburg, Germany; (J.O.); (R.S.)
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2
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Lowry AJ, Liang P, Song M, Serena Wan YC, Pei ZM, Yang H, Zhang Y. TMEM16 and OSCA/TMEM63 proteins share a conserved potential to permeate ions and phospholipids. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.04.578431. [PMID: 38370744 PMCID: PMC10871192 DOI: 10.1101/2024.02.04.578431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
The calcium-activated TMEM16 proteins and the mechanosensitive/osmolarity-activated OSCA/TMEM63 proteins belong to the Transmembrane Channel/Scramblase (TCS) superfamily. Within the superfamily, OSCA/TMEM63 proteins, as well as TMEM16A and TMEM16B, are thought to function solely as ion channels. However, most TMEM16 members, including TMEM16F, maintain an additional function as scramblases, rapidly exchanging phospholipids between leaflets of the membrane. Although recent studies have advanced our understanding of TCS structure-function relationships, the molecular determinants of TCS ion and lipid permeation remain unclear. Here we show that single mutations along the transmembrane helix (TM) 4/6 interface allow non-scrambling TCS members to permeate phospholipids. In particular, this study highlights the key role of TM 4 in controlling TCS ion and lipid permeation and offers novel insights into the evolution of the TCS superfamily, suggesting that, like TMEM16s, the OSCA/TMEM63 family maintains a conserved potential to permeate ions and phospholipids.
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Affiliation(s)
- Augustus J Lowry
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Pengfei Liang
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mo Song
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Guangdong 518106, China
| | - Y C Serena Wan
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
| | - Zhen-Ming Pei
- Department of Biology, Duke University, Durham, NC 27710, USA
| | - Huanghe Yang
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Neurobiology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Yang Zhang
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Guangdong 518106, China
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3
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Ebrahim S, Ballesteros A, Zheng WS, Mukherjee S, Hu G, Weng WH, Montgomery JS, Agyemang Y, Cui R, Sun W, Krystofiak E, Foster MP, Sotomayor M, Kachar B. Transmembrane channel-like 4 and 5 proteins at microvillar tips are potential ion channels and lipid scramblases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.22.609173. [PMID: 39229161 PMCID: PMC11370596 DOI: 10.1101/2024.08.22.609173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2024]
Abstract
Microvilli-membrane bound actin protrusions on the surface of epithelial cells-are sites of critical processes including absorption, secretion, and adhesion. Increasing evidence suggests microvilli are mechanosensitive, but underlying molecules and mechanisms remain unknown. Here, we localize transmembrane channel-like proteins 4 and 5 (TMC4 and 5) and calcium and integrin binding protein 3 (CIB3) to microvillar tips in intestinal epithelial cells, near glycocalyx insertion sites. We find that TMC5 colocalizes with CIB3 in cultured cells and that a TMC5 fragment forms a complex with CIB3 in vitro. Homology and AlphaFold2 models reveal a putative ion permeation pathway in TMC4 and 5, and molecular dynamics simulations predict both proteins can conduct ions and perform lipid scrambling. These findings raise the possibility that TMC4 and 5 interact with CIB3 at microvillar tips to form a mechanosensitive complex, akin to TMC1 and 2, and CIB2 and 3, within the mechanotransduction channel complex at the tips of inner ear stereocilia.
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Affiliation(s)
- Seham Ebrahim
- Center for Membrane and Cell Physiology, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22903, USA
| | - Angela Ballesteros
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
- Section on Sensory Physiology and Biophysics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - W Sharon Zheng
- Center for Membrane and Cell Physiology, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22903, USA
| | - Shounak Mukherjee
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Gaizun Hu
- Center for Membrane and Cell Physiology, Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22903, USA
| | - Wei-Hsiang Weng
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- Biophysics Program, The Ohio State University, Columbus, OH 43210, USA
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
| | - Jonathan S Montgomery
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Yaw Agyemang
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Runjia Cui
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Willy Sun
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Evan Krystofiak
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
| | - Mark P Foster
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- Biophysics Program, The Ohio State University, Columbus, OH 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
- Biophysics Program, The Ohio State University, Columbus, OH 43210, USA
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL 60637, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
| | - Bechara Kachar
- Laboratory of Cell Structure and Dynamics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, MD 20892, USA
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4
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Chakraborty S, Feng Z, Lee S, Alvarenga OE, Panda A, Bruni R, Khelashvili G, Gupta K, Accardi A. Structure and function of the human apoptotic scramblase Xkr4. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.07.607004. [PMID: 39149361 PMCID: PMC11326236 DOI: 10.1101/2024.08.07.607004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Phosphatidylserine externalization on the surface of dying cells is a key signal for their recognition and clearance by macrophages and is mediated by members of the X-Kell related (Xkr) protein family. Defective Xkr-mediated scrambling impairs clearance, leading to inflammation. It was proposed that activation of the Xkr4 apoptotic scramblase requires caspase cleavage, followed by dimerization and ligand binding. Here, using a combination of biochemical approaches we show that purified monomeric, full-length human Xkr4 (hXkr4) scrambles lipids. CryoEM imaging shows that hXkr4 adopts a novel conformation, where three conserved acidic residues create an electronegative surface embedded in the membrane. Molecular dynamics simulations show this conformation induces membrane thinning, which could promote scrambling. Thinning is ablated or reduced in conditions where scrambling is abolished or reduced. Our work provides insights into the molecular mechanisms of hXkr4 scrambling and suggests the ability to thin membranes might be a general property of active scramblases.
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Affiliation(s)
| | - Zhang Feng
- Department of Anesthesiology, Weill Cornell Medical College
| | - Sangyun Lee
- Department of Anesthesiology, Weill Cornell Medical College
| | - Omar E. Alvarenga
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Medical College
| | - Aniruddha Panda
- Nanobiology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Renato Bruni
- Center on Membrane Protein Production and Analysis (COMPPÅ), New York Structural Biology Center, New York, NY 10027, USA
| | | | - Kallol Gupta
- Nanobiology Institute, Yale University, West Haven, Connecticut 06516, United States
- Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06520, United States
| | - Alessio Accardi
- Department of Anesthesiology, Weill Cornell Medical College
- Department of Physiology and Biophysics, Weill Cornell Medical College
- Department of Biochemistry, Weill Cornell Medical College
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Liang Z, Dondorp DC, Chatzigeorgiou M. The ion channel Anoctamin 10/TMEM16K coordinates organ morphogenesis across scales in the urochordate notochord. PLoS Biol 2024; 22:e3002762. [PMID: 39173068 PMCID: PMC11341064 DOI: 10.1371/journal.pbio.3002762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Accepted: 07/20/2024] [Indexed: 08/24/2024] Open
Abstract
During embryonic development, tissues and organs are gradually shaped into their functional morphologies through a series of spatiotemporally tightly orchestrated cell behaviors. A highly conserved organ shape across metazoans is the epithelial tube. Tube morphogenesis is a complex multistep process of carefully choreographed cell behaviors such as convergent extension, cell elongation, and lumen formation. The identity of the signaling molecules that coordinate these intricate morphogenetic steps remains elusive. The notochord is an essential tubular organ present in the embryonic midline region of all members of the chordate phylum. Here, using genome editing, pharmacology and quantitative imaging in the early chordate Ciona intestinalis we show that Ano10/Tmem16k, a member of the evolutionarily ancient family of transmembrane proteins called Anoctamin/TMEM16 is essential for convergent extension, lumen expansion, and connection during notochord morphogenesis. We find that Ano10/Tmem16k works in concert with the plasma membrane (PM) localized Na+/Ca2+ exchanger (NCX) and the endoplasmic reticulum (ER) residing SERCA, RyR, and IP3R proteins to establish developmental stage specific Ca2+ signaling molecular modules that regulate notochord morphogenesis and Ca2+ dynamics. In addition, we find that the highly conserved Ca2+ sensors calmodulin (CaM) and Ca2+/calmodulin-dependent protein kinase (CaMK) show an Ano10/Tmem16k-dependent subcellular localization. Their pharmacological inhibition leads to convergent extension, tubulogenesis defects, and deranged Ca2+ dynamics, suggesting that Ano10/Tmem16k is involved in both the "encoding" and "decoding" of developmental Ca2+ signals. Furthermore, Ano10/Tmem16k mediates cytoskeletal reorganization during notochord morphogenesis, likely by altering the localization of 2 important cytoskeletal regulators, the small GTPase Ras homolog family member A (RhoA) and the actin binding protein Cofilin. Finally, we use electrophysiological recordings and a scramblase assay in tissue culture to demonstrate that Ano10/Tmem16k likely acts as an ion channel but not as a phospholipid scramblase. Our results establish Ano10/Tmem16k as a novel player in the prevertebrate molecular toolkit that controls organ morphogenesis across scales.
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Affiliation(s)
- Zonglai Liang
- Michael Sars Centre, University of Bergen, Bergen, Norway
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6
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Lin WY, Chung WY, Muallem S. The tether function of the anoctamins. Cell Calcium 2024; 121:102875. [PMID: 38701708 PMCID: PMC11166512 DOI: 10.1016/j.ceca.2024.102875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 03/17/2024] [Accepted: 03/20/2024] [Indexed: 05/05/2024]
Abstract
The core functions of the anoctamins are Cl- channel activity and phosphatidylserine (and perhaps other lipids) scrambling. These functions have been extensively studied in various tissues and cells. However, another function of the anoctamins that is less recognized and minimally explored is as tethers at membrane contact sites. This short review aims to examine evidence supporting the localization of the anoctamins at membrane contact sites, their tether properties, and their functions as tethers.
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Affiliation(s)
- Wei-Yin Lin
- From the Epithelial Signaling and Transport Section, National Institute of Dental Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Woo Young Chung
- From the Epithelial Signaling and Transport Section, National Institute of Dental Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
| | - Shmuel Muallem
- From the Epithelial Signaling and Transport Section, National Institute of Dental Craniofacial Research, National Institutes of Health, Bethesda, MD 20892, USA
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7
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Feng Z, Di Zanni E, Alvarenga O, Chakraborty S, Rychlik N, Accardi A. In or out of the groove? Mechanisms of lipid scrambling by TMEM16 proteins. Cell Calcium 2024; 121:102896. [PMID: 38749289 PMCID: PMC11178363 DOI: 10.1016/j.ceca.2024.102896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 04/30/2024] [Accepted: 04/30/2024] [Indexed: 06/13/2024]
Abstract
Phospholipid scramblases mediate the rapid movement of lipids between membrane leaflets, a key step in establishing and maintaining membrane homeostasis of the membranes of all eukaryotic cells and their organelles. Thus, impairment of lipid scrambling can lead to a variety of pathologies. How scramblases catalyzed the transbilayer movement of lipids remains poorly understood. Despite the availability of direct structural information on three unrelated families of scramblases, the TMEM16s, the Xkrs, and ATG-9, a unifying mechanism has failed to emerge thus far. Among these, the most extensively studied and best understood are the Ca2+ activated TMEM16s, which comprise ion channels and/or scramblases. Early work supported the view that these proteins provided a hydrophilic, membrane-exposed groove through which the lipid headgroups could permeate. However, structural, and functional experiments have since challenged this mechanism, leading to the proposal that the TMEM16s distort and thin the membrane near the groove to facilitate lipid scrambling. Here, we review our understanding of the structural and mechanistic underpinnings of lipid scrambling by the TMEM16s and discuss how the different proposals account for the various experimental observations.
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Affiliation(s)
- Zhang Feng
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, United States
| | - Eleonora Di Zanni
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, United States
| | - Omar Alvarenga
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, United States; Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, United States
| | - Sayan Chakraborty
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, United States
| | - Nicole Rychlik
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, United States; Institute of Physiology I, University of Münster, Robert-Koch-Str. 27a, D-48149 Münster, Germany
| | - Alessio Accardi
- Department of Anesthesiology, Weill Cornell Medicine, New York, NY, United States; Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, United States; Department of Biochemistry, Weill Cornell Medicine, New York, NY, United States.
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8
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Genovese M, Galietta LJV. Anoctamin pharmacology. Cell Calcium 2024; 121:102905. [PMID: 38788257 DOI: 10.1016/j.ceca.2024.102905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/07/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024]
Abstract
TMEM16 proteins, also known as anoctamins, are a family of ten membrane proteins with various tissue expression and subcellular localization. TMEM16A (anoctamin 1) is a plasma membrane protein that acts as a calcium-activated chloride channel. It is expressed in many types of epithelial cells, smooth muscle cells and some neurons. In airway epithelial cells, TMEM16A expression is particularly enhanced by inflammatory stimuli that also promote goblet cell metaplasia and mucus hypersecretion. Therefore, pharmacological modulation of TMEM16A could be beneficial to improve mucociliary clearance in chronic obstructive respiratory diseases. However, the correct approach to modulate TMEM16A activity (activation or inhibition) is still debated. Pharmacological inhibitors of TMEM16A could also be useful as anti-hypertensive agents given the TMEM16A role in smooth muscle contraction. In contrast to TMEM16A, TMEM16F (anoctamin 6) behaves as a calcium-activated phospholipid scramblase, responsible for the externalization of phosphatidylserine on cell surface. Inhibitors of TMEM16F could be useful as anti-coagulants and anti-viral agents. The role of other anoctamins as therapeutic targets is still unclear since their physiological role is still to be defined.
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Affiliation(s)
- Michele Genovese
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli (NA), Italy
| | - Luis J V Galietta
- Telethon Institute of Genetics and Medicine (TIGEM), Pozzuoli (NA), Italy; Department of Translational Medical Sciences (DISMET), University of Naples "Federico II", Italy.
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Ousingsawat J, Talbi K, Gómez-Martín H, Koy A, Fernández-Jaén A, Tekgül H, Serdaroğlu E, Schreiber R, Ortigoza-Escobar JD, Kunzelmann K. Broadening the clinical spectrum: molecular mechanisms and new phenotypes of ANO3-dystonia. Brain 2024; 147:1982-1995. [PMID: 38079528 DOI: 10.1093/brain/awad412] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 11/02/2023] [Accepted: 11/18/2023] [Indexed: 06/04/2024] Open
Abstract
Anoctamin 3 (ANO3) belongs to a family of transmembrane proteins that form phospholipid scramblases and ion channels. A large number of ANO3 variants were identified as the cause of craniocervical dystonia, but the underlying pathogenic mechanisms remain obscure. It was suggested that ANO3 variants may dysregulate intracellular Ca2+ signalling, as variants in other Ca2+ regulating proteins like hippocalcin were also identified as a cause of dystonia. In this study, we conducted a comprehensive evaluation of the clinical, radiological and molecular characteristics of four individuals from four families who carried heterozygous variants in ANO3. The median age at follow-up was 6.6 years (ranging from 3.8 to 8.7 years). Three individuals presented with hypotonia and motor developmental delay. Two patients exhibited generalized progressive dystonia, while one patient presented with paroxysmal dystonia. Additionally, another patient exhibited early dyskinetic encephalopathy. One patient underwent bipallidal deep brain stimulation (DBS) and showed a mild but noteworthy response, while another patient is currently being considered for DBS treatment. Neuroimaging analysis of brain MRI studies did not reveal any specific abnormalities. The molecular spectrum included two novel ANO3 variants (V561L and S116L) and two previously reported ANO3 variants (A599D and S651N). As anoctamins are suggested to affect intracellular Ca2+ signals, we compared Ca2+ signalling and activation of ion channels in cells expressing wild-type ANO3 and cells expressing anoctamin variants. Novel V561L and S116L variants were compared with previously reported A599D and S651N variants and with wild-type ANO3 expressed in fibroblasts isolated from patients or when overexpressed in HEK293 cells. We identified ANO3 as a Ca2+-activated phospholipid scramblase that also conducts ions. Impaired Ca2+ signalling and compromised activation of Ca2+-dependent K+ channels were detected in cells expressing ANO3 variants. In the brain striatal cells of affected patients, impaired activation of KCa3.1 channels due to compromised Ca2+ signals may lead to depolarized membrane voltage and neuronal hyperexcitability and may also lead to reduced cellular viability, as shown in the present study. In conclusion, our study reveals the association between ANO3 variants and paroxysmal dystonia, representing the first reported link between these variants and this specific dystonic phenotype. We demonstrate that ANO3 functions as a Ca2+-activated phospholipid scramblase and ion channel; cells expressing ANO3 variants exhibit impaired Ca2+ signalling and compromised activation of Ca2+-dependent K+ channels. These findings provide a mechanism for the observed clinical manifestations and highlight the importance of ANO3 for neuronal excitability and cellular viability.
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Affiliation(s)
| | - Khaoula Talbi
- Physiological Institute, University of Regensburg, D-93053 Regensburg, Germany
| | - Hilario Gómez-Martín
- Pediatric Neurology Unit, Department of Pediatrics, Hospital Universitario de Salamanca, 37007 Castilla y Leon, Spain
| | - Anne Koy
- Centre for Rare Diseases, Faculty of Medicine and University Hospital Cologne, University of Cologne, 50931 Köln, Germany
- Department of Pediatrics, Faculty of Medicine and University, Hospital Cologne, University of Cologne, 50931 Köln, Germany
| | - Alberto Fernández-Jaén
- Department of Pediatric Neurology, Hospital Universitario Quirónsalud, 28223 Pozuelo de Alarcón, Madrid, Spain
- School of Medicine, Universidad Europea De Madrid, 28670 Villaviciosa de Odón, Madrid, Spain
| | - Hasan Tekgül
- Division of Pediatric Neurology, Ege Children's Hospital, Ege University Medical School, 35100 Bornova, Izmir, Turkey
| | - Esra Serdaroğlu
- Department of Pediatric Neurology, Gazi University, Emniyet, 06560 Yenimahalle, Ankara, Turkey
| | - Rainer Schreiber
- Physiological Institute, University of Regensburg, D-93053 Regensburg, Germany
| | - Juan Dario Ortigoza-Escobar
- U-703 Centre for Biomedical Research on Rare Diseases (CIBER-ER), Instituto de Salud Carlos III, 08003 Barcelona, Spain
- Movement Disorders Unit, Pediatric Neurology Department, Institut de Recerca Hospital Sant Joan de Déu, 08950 Barcelona, Spain
- European Reference Network for Rare Neurological Diseases (ERN-RND), 08950 Barcelona, Spain
| | - Karl Kunzelmann
- Physiological Institute, University of Regensburg, D-93053 Regensburg, Germany
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10
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Schreiber R, Ousingsawat J, Kunzelmann K. The anoctamins: Structure and function. Cell Calcium 2024; 120:102885. [PMID: 38642428 DOI: 10.1016/j.ceca.2024.102885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 04/03/2024] [Accepted: 04/04/2024] [Indexed: 04/22/2024]
Abstract
When activated by increase in intracellular Ca2+, anoctamins (TMEM16 proteins) operate as phospholipid scramblases and as ion channels. Anoctamin 1 (ANO1) is the Ca2+-activated epithelial anion-selective channel that is coexpressed together with the abundant scramblase ANO6 and additional intracellular anoctamins. In salivary and pancreatic glands, ANO1 is tightly packed in the apical membrane and secretes Cl-. Epithelia of airways and gut use cystic fibrosis transmembrane conductance regulator (CFTR) as an apical Cl- exit pathway while ANO1 supports Cl- secretion mainly by facilitating activation of luminal CFTR and basolateral K+ channels. Under healthy conditions ANO1 modulates intracellular Ca2+ signals by tethering the endoplasmic reticulum, and except of glands its direct secretory contribution as Cl- channel might be small, compared to CFTR. In the kidneys ANO1 supports proximal tubular acid secretion and protein reabsorption and probably helps to excrete HCO3-in the collecting duct epithelium. However, under pathological conditions as in polycystic kidney disease, ANO1 is strongly upregulated and may cause enhanced proliferation and cyst growth. Under pathological condition, ANO1 and ANO6 are upregulated and operate as secretory channel/phospholipid scramblases, partly by supporting Ca2+-dependent processes. Much less is known about the role of other epithelial anoctamins whose potential functions are discussed in this review.
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Affiliation(s)
- Rainer Schreiber
- Physiological Institute, University of Regensburg, University street 31, D-93053 Regensburg, Germany
| | - Jiraporn Ousingsawat
- Physiological Institute, University of Regensburg, University street 31, D-93053 Regensburg, Germany
| | - Karl Kunzelmann
- Physiological Institute, University of Regensburg, University street 31, D-93053 Regensburg, Germany.
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11
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Kunzelmann K, Ousingsawat J, Schreiber R. VSI: The anoctamins: Structure and function: "Intracellular" anoctamins. Cell Calcium 2024; 120:102888. [PMID: 38657371 DOI: 10.1016/j.ceca.2024.102888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 04/15/2024] [Accepted: 04/16/2024] [Indexed: 04/26/2024]
Abstract
Plasma membrane localized anoctamin 1, 2 and 6 (TMEM16A, B, F) have been examined in great detail with respect to structure and function, but much less is known about the other seven intracellular members of this exciting family of proteins. This is probably due to their limited accessibility in intracellular membranous compartments, such as the endoplasmic reticulum (ER) or endosomes. However, these so-called intracellular anoctamins are also found in the plasma membrane (PM) which adds to the confusion regarding their cellular role. Probably all intracellular anoctamins except of ANO8 operate as intracellular phospholipid (PL) scramblases, allowing for Ca2+-activated, passive transport of phospholipids like phosphatidylserine between both membrane leaflets. Probably all of them also conduct ions, which is probably part of their physiological function. In this brief overview, we summarize key findings on the biological functions of ANO3, 4, 5, 7, 8, 9 and 10 (TMEM16C, D, E, G, H, J, K) that are gradually coming to light. Compartmentalized regulation of intracellular Ca2+ signals, tethering of the ER to specific PM contact sites, and control of intracellular vesicular trafficking appear to be some of the functions of intracellular anoctamins, while loss of function and abnormal expression are the cause for various diseases.
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Affiliation(s)
- Karl Kunzelmann
- Physiological Institute, University of Regensburg, University street 31, D-93053, Regensburg, Germany.
| | - Jiraporn Ousingsawat
- Physiological Institute, University of Regensburg, University street 31, D-93053, Regensburg, Germany
| | - Rainer Schreiber
- Physiological Institute, University of Regensburg, University street 31, D-93053, Regensburg, Germany
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12
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Dibattista M, Pifferi S, Hernandez-Clavijo A, Menini A. The physiological roles of anoctamin2/TMEM16B and anoctamin1/TMEM16A in chemical senses. Cell Calcium 2024; 120:102889. [PMID: 38677213 DOI: 10.1016/j.ceca.2024.102889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2024] [Revised: 04/11/2024] [Accepted: 04/17/2024] [Indexed: 04/29/2024]
Abstract
Chemical senses allow animals to detect and discriminate a vast array of molecules. The olfactory system is responsible of the detection of small volatile molecules, while water dissolved molecules are detected by taste buds in the oral cavity. Moreover, many animals respond to signaling molecules such as pheromones and other semiochemicals through the vomeronasal organ. The peripheral organs dedicated to chemical detection convert chemical signals into perceivable information through the employment of diverse receptor types and the activation of multiple ion channels. Two ion channels, TMEM16B, also known as anoctamin2 (ANO2) and TMEM16A, or anoctamin1 (ANO1), encoding for Ca2+-activated Cl¯ channels, have been recently described playing critical roles in various cell types. This review aims to discuss the main properties of TMEM16A and TMEM16B-mediated currents and their physiological roles in chemical senses. In olfactory sensory neurons, TMEM16B contributes to amplify the odorant response, to modulate firing, response kinetics and adaptation. TMEM16A and TMEM16B shape the pattern of action potentials in vomeronasal sensory neurons increasing the interspike interval. In type I taste bud cells, TMEM16A is activated during paracrine signaling mediated by ATP. This review aims to shed light on the regulation of diverse signaling mechanisms and neuronal excitability mediated by Ca-activated Cl¯ channels, hinting at potential new roles for TMEM16A and TMEM16B in the chemical senses.
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Affiliation(s)
- Michele Dibattista
- Department of Translational Biomedicine and Neuroscience, University of Bari A. Moro, 70121 Bari, Italy
| | - Simone Pifferi
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60126 Ancona, Italy.
| | - Andres Hernandez-Clavijo
- Department of Chemosensation, Institute for Biology II, RWTH Aachen University, 52074 Aachen, Germany
| | - Anna Menini
- Neurobiology Group, SISSA, Scuola Internazionale Superiore di Studi Avanzati, 34136 Trieste, Italy.
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13
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Silvaroli JA, Bisunke B, Kim JY, Stayton A, Jayne LA, Martinez SA, Nguyen C, Patel PS, Vanichapol T, Verma V, Akhter J, Bolisetty S, Madhavan SM, Kuscu C, Coss CC, Zepeda-Orozco D, Parikh SV, Satoskar AA, Davidson AJ, Eason JD, Szeto HH, Pabla NS, Bajwa A. Genome-Wide CRISPR Screen Identifies Phospholipid Scramblase 3 as the Biological Target of Mitoprotective Drug SS-31. J Am Soc Nephrol 2024; 35:681-695. [PMID: 38530359 PMCID: PMC11164119 DOI: 10.1681/asn.0000000000000338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 03/12/2024] [Indexed: 03/27/2024] Open
Abstract
Key Points Szeto–Schiller-31–mediated mitoprotection is phospholipid scramblase 3–dependent. Phospholipid scramblase 3 is required for recovery after AKI. Background The synthetic tetrapeptide Szeto–Schiller (SS)-31 shows promise in alleviating mitochondrial dysfunction associated with common diseases. However, the precise pharmacological basis of its mitoprotective effects remains unknown. Methods To uncover the biological targets of SS-31, we performed a genome-scale clustered regularly interspaced short palindromic repeats screen in human kidney-2, a cell culture model where SS-31 mitigates cisplatin-associated cell death and mitochondrial dysfunction. The identified hit candidate gene was functionally validated using knockout cell lines, small interfering RNA-mediated downregulation, and tubular epithelial–specific conditional knockout mice. Biochemical interaction studies were also performed to examine the interaction of SS-31 with the identified target protein. Results Our primary screen and validation studies in hexokinase 2 and primary murine tubular epithelial cells showed that phospholipid scramblase 3 (PLSCR3), an understudied inner mitochondrial membrane protein, was essential for the protective effects of SS-31. For in vivo validation, we generated tubular epithelial–specific knockout mice and found that Plscr3 gene ablation did not influence kidney function under normal conditions or affect the severity of cisplatin and rhabdomyolysis-associated AKI. However, Plscr3 gene deletion completely abrogated the protective effects of SS-31 during cisplatin and rhabdomyolysis-associated AKI. Biochemical studies showed that SS-31 directly binds to a previously uncharacterized N -terminal domain and stimulates PLSCR3 scramblase activity. Finally, PLSCR3 protein expression was found to be increased in the kidneys of patients with AKI. Conclusions PLSCR3 was identified as the essential biological target that facilitated the mitoprotective effects of SS-31 in vitro and in vivo .
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Affiliation(s)
- Josie A. Silvaroli
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Bijay Bisunke
- Department of Genetics, Genomics, and Informatics; College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Ji Young Kim
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Amanda Stayton
- Department of Genetics, Genomics, and Informatics; College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Laura A. Jayne
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Shirely A. Martinez
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Christopher Nguyen
- Department of Genetics, Genomics, and Informatics; College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Prisha S. Patel
- Department of Genetics, Genomics, and Informatics; College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Thitinee Vanichapol
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - Vivek Verma
- Department of Medicine, University of Alabama, Birmingham, Alabama
| | - Juheb Akhter
- Department of Medicine, University of Alabama, Birmingham, Alabama
| | | | - Sethu M. Madhavan
- Division of Nephrology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Cem Kuscu
- Department of Surgery, College of Medicine, Transplant Research Institute, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Christopher C. Coss
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Diana Zepeda-Orozco
- Department of Pediatrics, The Ohio State University College of Medicine and Kidney and Urinary Tract Research Center, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, Ohio
| | - Samir V. Parikh
- Division of Nephrology, Department of Medicine, The Ohio State University, Columbus, Ohio
| | - Anjali A. Satoskar
- Division of Renal and Transplant Pathology, Department of Pathology, The Ohio State University Wexner Medical Center, Columbus, Ohio
| | - Alan J. Davidson
- Department of Molecular Medicine and Pathology, University of Auckland, Auckland, New Zealand
| | - James D. Eason
- Department of Surgery, College of Medicine, Transplant Research Institute, The University of Tennessee Health Science Center, Memphis, Tennessee
| | - Hazel H. Szeto
- Social Profit Network Research Lab, Menlo Park, California
| | - Navjot S. Pabla
- Division of Pharmaceutics and Pharmacology, College of Pharmacy and Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio
| | - Amandeep Bajwa
- Department of Genetics, Genomics, and Informatics; College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Surgery, College of Medicine, Transplant Research Institute, The University of Tennessee Health Science Center, Memphis, Tennessee
- Department of Microbiology, Immunology, and Biochemistry; College of Medicine, The University of Tennessee Health Science Center, Memphis, Tennessee
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14
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Moran O, Tammaro P. Identification of determinants of lipid and ion transport in TMEM16/anoctamin proteins through a Bayesian statistical analysis. Biophys Chem 2024; 308:107194. [PMID: 38401241 DOI: 10.1016/j.bpc.2024.107194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Revised: 01/17/2024] [Accepted: 01/28/2024] [Indexed: 02/26/2024]
Abstract
The TMEM16/Anoctamin protein family (TMEM16x) is composed of members with different functions; some members form Ca2+-activated chloride channels, while others are lipid scramblases or combine the two functions. TMEM16x proteins are typically activated in response to agonist-induced rises of intracellular Ca2+; thus, they couple Ca2+-signalling with cell electrical activity or plasmalemmal lipid homeostasis. The structural domains underlying these functions are not fully defined. We used a Naïve Bayes classifier to gain insights into these domains. The method enabled identification of regions involved in either ion or lipid transport, and suggested domains for possible pharmacological exploitation. The method allowed the prediction of the transport property of any given TMEM16x. We envisage this strategy could be exploited to illuminate the structure-function relationship of any protein family composed of members playing different molecular roles.
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Affiliation(s)
- Oscar Moran
- Istituto di Biofisica, Consiglio Nazionale delle Ricerche (CNR), Via De Marini 6, 16149 Genova, Italy
| | - Paolo Tammaro
- Department Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK.
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15
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Feng Z, Alvarenga OE, Accardi A. Structural basis of closed groove scrambling by a TMEM16 protein. Nat Struct Mol Biol 2024:10.1038/s41594-024-01284-9. [PMID: 38684930 DOI: 10.1038/s41594-024-01284-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 03/21/2024] [Indexed: 05/02/2024]
Abstract
Activation of Ca2+-dependent TMEM16 scramblases induces phosphatidylserine externalization, a key step in multiple signaling processes. Current models suggest that the TMEM16s scramble lipids by deforming the membrane near a hydrophilic groove and that Ca2+ dependence arises from the different association of lipids with an open or closed groove. However, the molecular rearrangements underlying groove opening and how lipids reorganize outside the closed groove remain unknown. Here we directly visualize how lipids associate at the closed groove of Ca2+-bound fungal nhTMEM16 in nanodiscs using cryo-EM. Functional experiments pinpoint lipid-protein interaction sites critical for closed groove scrambling. Structural and functional analyses suggest groove opening entails the sequential appearance of two π-helical turns in the groove-lining TM6 helix and identify critical rearrangements. Finally, we show that the choice of scaffold protein and lipids affects the conformations of nhTMEM16 and their distribution, highlighting a key role of these factors in cryo-EM structure determination.
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Affiliation(s)
- Zhang Feng
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY, USA
| | - Omar E Alvarenga
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Medical College, New York, NY, USA
| | - Alessio Accardi
- Department of Anesthesiology, Weill Cornell Medical College, New York, NY, USA.
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York, NY, USA.
- Department of Biochemistry, Weill Cornell Medical College, New York, NY, USA.
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16
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Li D, Rocha-Roa C, Schilling MA, Reinisch KM, Vanni S. Lipid scrambling is a general feature of protein insertases. Proc Natl Acad Sci U S A 2024; 121:e2319476121. [PMID: 38621120 PMCID: PMC11047089 DOI: 10.1073/pnas.2319476121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Accepted: 03/13/2024] [Indexed: 04/17/2024] Open
Abstract
Glycerophospholipids are synthesized primarily in the cytosolic leaflet of the endoplasmic reticulum (ER) membrane and must be equilibrated between bilayer leaflets to allow the ER and membranes derived from it to grow. Lipid equilibration is facilitated by integral membrane proteins called "scramblases." These proteins feature a hydrophilic groove allowing the polar heads of lipids to traverse the hydrophobic membrane interior, similar to a credit card moving through a reader. Nevertheless, despite their fundamental role in membrane expansion and dynamics, the identity of most scramblases has remained elusive. Here, combining biochemical reconstitution and molecular dynamics simulations, we show that lipid scrambling is a general feature of protein insertases, integral membrane proteins which insert polypeptide chains into membranes of the ER and organelles disconnected from vesicle trafficking. Our data indicate that lipid scrambling occurs in the same hydrophilic channel through which protein insertion takes place and that scrambling is abolished in the presence of nascent polypeptide chains. We propose that protein insertases could have a so-far-overlooked role in membrane dynamics as scramblases.
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Affiliation(s)
- Dazhi Li
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - Cristian Rocha-Roa
- Department of Biology, University of Fribourg, FribourgCH-1700, Switzerland
| | - Matthew A. Schilling
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - Karin M. Reinisch
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT06520
| | - Stefano Vanni
- Department of Biology, University of Fribourg, FribourgCH-1700, Switzerland
- Swiss National Center for Competence in Research Bio-Inspired Materials, University of Fribourg, FribourgCH-1700, Switzerland
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17
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Jojoa-Cruz S, Dubin AE, Lee WH, Ward AB. Structure-guided mutagenesis of OSCAs reveals differential activation to mechanical stimuli. eLife 2024; 12:RP93147. [PMID: 38592763 PMCID: PMC11003742 DOI: 10.7554/elife.93147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/10/2024] Open
Abstract
The dimeric two-pore OSCA/TMEM63 family has recently been identified as mechanically activated ion channels. Previously, based on the unique features of the structure of OSCA1.2, we postulated the potential involvement of several structural elements in sensing membrane tension (Jojoa-Cruz et al., 2018). Interestingly, while OSCA1, 2, and 3 clades are activated by membrane stretch in cell-attached patches (i.e. they are stretch-activated channels), they differ in their ability to transduce membrane deformation induced by a blunt probe (poking). Here, in an effort to understand the domains contributing to mechanical signal transduction, we used cryo-electron microscopy to solve the structure of Arabidopsis thaliana (At) OSCA3.1, which, unlike AtOSCA1.2, only produced stretch- but not poke-activated currents in our initial characterization (Murthy et al., 2018). Mutagenesis and electrophysiological assessment of conserved and divergent putative mechanosensitive features of OSCA1.2 reveal a selective disruption of the macroscopic currents elicited by poking without considerable effects on stretch-activated currents (SAC). Our results support the involvement of the amphipathic helix and lipid-interacting residues in the membrane fenestration in the response to poking. Our findings position these two structural elements as potential sources of functional diversity within the family.
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Affiliation(s)
- Sebastian Jojoa-Cruz
- Department of Integrative Structural and Computational Biology, Scripps ResearchLa JollaUnited States
| | - Adrienne E Dubin
- Department of Integrative Structural and Computational Biology, Scripps ResearchLa JollaUnited States
- Department of Neuroscience, Scripps ResearchLa JollaUnited States
| | - Wen-Hsin Lee
- Department of Integrative Structural and Computational Biology, Scripps ResearchLa JollaUnited States
| | - Andrew B Ward
- Department of Integrative Structural and Computational Biology, Scripps ResearchLa JollaUnited States
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18
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Jojoa-Cruz S, Dubin AE, Lee WH, Ward A. Structure-guided mutagenesis of OSCAs reveals differential activation to mechanical stimuli. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.03.560740. [PMID: 37873218 PMCID: PMC10592937 DOI: 10.1101/2023.10.03.560740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
The dimeric two-pore OSCA/TMEM63 family has recently been identified as mechanically activated ion channels. Previously, based on the unique features of the structure of OSCA1.2, we postulated the potential involvement of several structural elements in sensing membrane tension1. Interestingly, while OSCA1, 2, and 3 clades are activated by membrane stretch in cell-attached patches (i.e., they are stretch-activated channels), they differ in their ability to transduce membrane deformation induced by a blunt probe (poking). In an effort to understand the domains contributing to mechanical signal transduction, we used cryo-electron microscopy to solve the structure of Arabidopsis thaliana (At) OSCA3.1, which, unlike AtOSCA1.2, only produced stretch- but not poke-activated currents in our initial characterization2. Mutagenesis and electrophysiological assessment of conserved and divergent putative mechanosensitive features of OSCA1.2 reveal a selective disruption of the macroscopic currents elicited by poking without considerable effects on stretch-activated currents (SAC). Our results support the involvement of the amphipathic helix and lipid-interacting residues in the membrane fenestration in the response to poking. Our findings position these two structural elements as potential sources of functional diversity within the family.
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Affiliation(s)
- Sebastian Jojoa-Cruz
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, California 92037, USA
| | - Adrienne E. Dubin
- Department of Neuroscience, Scripps Research, La Jolla, California 92037, USA
| | - Wen-Hsin Lee
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, California 92037, USA
| | - Andrew Ward
- Department of Integrative Structural and Computational Biology, Scripps Research, La Jolla, California 92037, USA
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19
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Zhang Y, Wu K, Li Y, Wu S, Warshel A, Bai C. Predicting Mutational Effects on Ca 2+-Activated Chloride Conduction of TMEM16A Based on a Simulation Study. J Am Chem Soc 2024; 146:4665-4679. [PMID: 38319142 DOI: 10.1021/jacs.3c11940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2024]
Abstract
The dysfunction and defects of ion channels are associated with many human diseases, especially for loss-of-function mutations in ion channels such as cystic fibrosis transmembrane conductance regulator mutations in cystic fibrosis. Understanding ion channels is of great current importance for both medical and fundamental purposes. Such an understanding should include the ability to predict mutational effects and describe functional and mechanistic effects. In this work, we introduce an approach to predict mutational effects based on kinetic information (including reaction barriers and transition state locations) obtained by studying the working mechanism of target proteins. Specifically, we take the Ca2+-activated chloride channel TMEM16A as an example and utilize the computational biology model to predict the mutational effects of key residues. Encouragingly, we verified our predictions through electrophysiological experiments, demonstrating a 94% prediction accuracy regarding mutational directions. The mutational strength assessed by Pearson's correlation coefficient is -0.80 between our calculations and the experimental results. These findings suggest that the proposed methodology is reliable and can provide valuable guidance for revealing functional mechanisms and identifying key residues of the TMEM16A channel. The proposed approach can be extended to a broad scope of biophysical systems.
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Affiliation(s)
- Yue Zhang
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong (Shenzhen), Shenzhen 518172, China
- School of Chemistry and Materials Science, University of Science and Technology of China, Hefei 230026, China
| | - Kang Wu
- South China Hospital, Health Science Center, Shenzhen University, Shenzhen 518116, China
| | - Yuqing Li
- South China Hospital, Health Science Center, Shenzhen University, Shenzhen 518116, China
| | - Song Wu
- South China Hospital, Health Science Center, Shenzhen University, Shenzhen 518116, China
| | - Arieh Warshel
- Department of Chemistry, University of Southern California, Los Angeles, California 90089-1062, United States
| | - Chen Bai
- Warshel Institute for Computational Biology, School of Life and Health Sciences, School of Medicine, The Chinese University of Hong Kong (Shenzhen), Shenzhen 518172, China
- Chenzhu Biotechnology Co., Ltd., Hangzhou 310005, China
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20
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Feng Z, Alvarenga OE, Accardi A. Structural basis of closed groove scrambling by a TMEM16 protein. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.08.11.553029. [PMID: 37609346 PMCID: PMC10441378 DOI: 10.1101/2023.08.11.553029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Activation of Ca2+-dependent TMEM16 scramblases induces the externalization of phosphatidylserine, a key molecule in multiple signaling processes. Current models suggest that the TMEM16s scramble lipids by deforming the membrane near a hydrophilic groove, and that Ca2+ dependence arises from the different association of lipids with an open or closed groove. However, the molecular rearrangements involved in groove opening and of how lipids reorganize outside the closed groove remain unknown. Using cryogenic electron microscopy, we directly visualize how lipids associate at the closed groove of Ca2+-bound nhTMEM16 in nanodiscs. Functional experiments pinpoint the lipid-protein interaction sites critical for closed groove scrambling. Structural and functional analyses suggest groove opening entails the sequential appearance of two π-helical turns in the groove-lining TM6 helix and identify critical rearrangements. Finally, we show that the choice of scaffold protein and lipids affects the conformations of nhTMEM16 and their distribution, highlighting a key role of these factors in cryoEM structure determination.
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Affiliation(s)
- Zhang Feng
- Department of Anesthesiology, Weill Cornell Medical College
| | - Omar E. Alvarenga
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Medical College
| | - Alessio Accardi
- Department of Anesthesiology, Weill Cornell Medical College
- Department of Physiology and Biophysics, Weill Cornell Medical College
- Department of Biochemistry, Weill Cornell Medical College
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21
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Shaikh SS, Goebel A, Lee MC, Nahorski MS, Shenker N, Pamela Y, Drissi I, Brown C, Ison G, Shaikh MF, Kuttikat A, Woods WA, Dixit A, Stouffer K, Clarke MC, Menon DK, Woods CG. Evidence of a genetic background predisposing to complex regional pain syndrome type 1. J Med Genet 2024; 61:163-170. [PMID: 37816627 PMCID: PMC10850724 DOI: 10.1136/jmg-2023-109236] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 09/02/2023] [Indexed: 10/12/2023]
Abstract
BACKGROUND Complex regional pain syndrome type 1 (CRPS-1) is a rare, disabling and sometimes chronic disorder usually arising after a trauma. This exploratory study examined whether patients with chronic CRPS-1 have a different genetic profile compared with those who do not have the condition. METHODS Exome sequencing was performed to seek altered non-synonymous SNP allele frequencies in a discovery cohort of well-characterised patients with chronic CRPS-1 (n=34) compared with population databases. Identified SNP alleles were confirmed by Sanger sequencing and sought in a replication cohort (n=50). Gene expression of peripheral blood macrophages was assessed. RESULTS In the discovery cohort, the rare allele frequencies of four non-synonymous SNPs were statistically increased. The replication cohort confirmed this finding. In a chronic pain cohort, these alleles were not overexpressed. In total, 25 out of 84 (29.8%) patients with CRPS-1 expressed a rare allele. The SNPs were rs41289586 in ANO10, rs28360457 in P2RX7, rs1126930 in PRKAG1 and rs80308281 in SLC12A9. Males were more likely than females to have a rare SNP allele, 8 out of 14 (57.1%) vs 17 out of 70 (24.3%) (Fisher's p=0.023). ANO10, P2RX7, PRKAG1 and SLC12A9 were all expressed in macrophages from healthy human controls. CONCLUSION A single SNP in each of the genes ANO10, P2RX7, PRKAG1 and SLC12A9 was associated with developing chronic CRPS-1, with more males than females expressing these rare alleles. Our work suggests the possibility that a permissive genetic background is an important factor in the development of CRPS-1.
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Affiliation(s)
- Samiha S Shaikh
- Medical Genetics, Cambridge Institute for Medical Research, Cambridge, Cambridgeshire, UK
| | - Andreas Goebel
- Pain Research Institute, Clinical Sciences Centre, University of Liverpool Faculty of Health and Life Sciences, Liverpool, UK
| | - Michael C Lee
- Department of Medicine, Addenbrooke's Hospital, Cambridge, Cambridgeshire, UK
| | - Michael S Nahorski
- Medical Genetics, Cambridge Institute for Medical Research, Cambridge, Cambridgeshire, UK
| | - Nicholas Shenker
- Department of Rheumatology, Addenbrooke's Hospital Rheumatology Department, Cambridge, Cambridgeshire, UK
| | - Yunisa Pamela
- Medical Genetics, Cambridge Institute for Medical Research, Cambridge, Cambridgeshire, UK
- Department of Biomedical Sciences, Universitas Padjadjaran, Bandung, Indonesia
| | - Ichrak Drissi
- Medical Genetics, Cambridge Institute for Medical Research, Cambridge, Cambridgeshire, UK
| | - Christopher Brown
- Department of Medicine, Addenbrooke's Hospital, Cambridge, Cambridgeshire, UK
| | - Gillian Ison
- Department of Medicine, Addenbrooke's Hospital, Cambridge, Cambridgeshire, UK
| | - Maliha F Shaikh
- Department of Rheumatology, Addenbrooke's Hospital Rheumatology Department, Cambridge, Cambridgeshire, UK
| | - Anoop Kuttikat
- Department of Rheumatology, Addenbrooke's Hospital Rheumatology Department, Cambridge, Cambridgeshire, UK
| | - William A Woods
- Medical Genetics, Cambridge Institute for Medical Research, Cambridge, Cambridgeshire, UK
| | - Abhishek Dixit
- Department of Medicine, Addenbrooke's Hospital, Cambridge, Cambridgeshire, UK
| | - Kaitlin Stouffer
- Medical Genetics, Cambridge Institute for Medical Research, Cambridge, Cambridgeshire, UK
| | - Murray Ch Clarke
- Heart and Lung Research Institute, Cambridge Biomedical Campus, Cambridge, Cambridgeshire, UK
| | - David K Menon
- Brain Physics Laboratory, University of Cambridge Department of Clinical Neurosciences, Cambridge, Cambridgeshire, UK
| | - C Geoffrey Woods
- Medical Genetics, Cambridge Institute for Medical Research, Cambridge, Cambridgeshire, UK
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22
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Kim E, Bang J, Sung JH, Lee J, Shin DH, Kim S, Lee BC. Generation of human TMEM16F-specific affibodies using purified TMEM16F. Front Mol Biosci 2024; 10:1319251. [PMID: 38274091 PMCID: PMC10808743 DOI: 10.3389/fmolb.2023.1319251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Accepted: 12/27/2023] [Indexed: 01/27/2024] Open
Abstract
Introduction: TMEM16 family proteins are involved in a variety of functions, including ion transport, phospholipid scrambling, and the regulation of membrane proteins. Among them, TMEM16F has dual functions as a phospholipid scramblase and a nonselective ion channel. TMEM16F is widely expressed and functions in platelet activation during blood clotting, bone formation, and T cell activation. Despite the functional importance of TMEM16F, the modulators of TMEM16F function have not been sufficiently studied. Method: In this study, we generated TMEM16F-specific affibodies by performing phage display with brain-specific TMEM16F (hTMEM16F) variant 1 purified from GnTi- cells expressing this variant in the presence of digitonin as a detergent. Purified human TMEM16F protein, which was proficient in transporting phospholipids in a Ca2+-dependent manner in proteoliposomes, was coated onto plates and then the phage library was added to fish out TMEM16F-binding affibodies. For the validation of interaction between affibodies and TMEM16F proteins, ELISA, bio-layer interferometry, and size exclusion chromatography were conducted. Results and Discussion: As a result, the full sequences of 38 candidates were acquired from 98 binding candidates. Then, we selected 10 candidates and purified seven of them from E. coli expressing these candidates. Using various assays, we confirmed that two affibodies bound to human TMEM16F with high affinity. These affibodies can be useful for therapeutical and diagnostic applications of TMEM16F-related cancer and neurodegenerative diseases. Future studies will be required to investigate the effects of these affibodies on TMEM16F function.
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Affiliation(s)
- Eunyoung Kim
- Korea Brain Research Institute, Neurovascular Unit Research Group, Daegu, Republic of Korea
| | - Jinho Bang
- Korea Institute of Ceramic Engineering and Technology, Bio-Healthcare Materials Center, Cheongju, Republic of Korea
- College of Pharmacy, Chungbuk National University, Cheongju, Republic of Korea
| | - Ji Hye Sung
- Korea Brain Research Institute, Neurovascular Unit Research Group, Daegu, Republic of Korea
| | - Jonghwan Lee
- Korea Institute of Ceramic Engineering and Technology, Bio-Healthcare Materials Center, Cheongju, Republic of Korea
| | - Dae Hwan Shin
- College of Pharmacy, Chungbuk National University, Cheongju, Republic of Korea
| | - Sunghyun Kim
- Korea Institute of Ceramic Engineering and Technology, Bio-Healthcare Materials Center, Cheongju, Republic of Korea
| | - Byoung-Cheol Lee
- Korea Brain Research Institute, Neurovascular Unit Research Group, Daegu, Republic of Korea
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23
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Ye Z, Galvanetto N, Puppulin L, Pifferi S, Flechsig H, Arndt M, Triviño CAS, Di Palma M, Guo S, Vogel H, Menini A, Franz CM, Torre V, Marchesi A. Structural heterogeneity of the ion and lipid channel TMEM16F. Nat Commun 2024; 15:110. [PMID: 38167485 PMCID: PMC10761740 DOI: 10.1038/s41467-023-44377-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Accepted: 12/11/2023] [Indexed: 01/05/2024] Open
Abstract
Transmembrane protein 16 F (TMEM16F) is a Ca2+-activated homodimer which functions as an ion channel and a phospholipid scramblase. Despite the availability of several TMEM16F cryogenic electron microscopy (cryo-EM) structures, the mechanism of activation and substrate translocation remains controversial, possibly due to restrictions in the accessible protein conformational space. In this study, we use atomic force microscopy under physiological conditions to reveal a range of structurally and mechanically diverse TMEM16F assemblies, characterized by variable inter-subunit dimerization interfaces and protomer orientations, which have escaped prior cryo-EM studies. Furthermore, we find that Ca2+-induced activation is associated to stepwise changes in the pore region that affect the mechanical properties of transmembrane helices TM3, TM4 and TM6. Our direct observation of membrane remodelling in response to Ca2+ binding along with additional electrophysiological analysis, relate this structural multiplicity of TMEM16F to lipid and ion permeation processes. These results thus demonstrate how conformational heterogeneity of TMEM16F directly contributes to its diverse physiological functions.
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Affiliation(s)
- Zhongjie Ye
- International School for Advanced Studies (SISSA), 34136, Trieste, Italy
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, 518055, Shenzhen, China
| | - Nicola Galvanetto
- Department of Physics, University of Zurich, 8057, Zurich, Switzerland
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | - Leonardo Puppulin
- Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, I-30172 Mestre, Venice, Italy
- WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, 920-1192, Kanazawa, Japan
| | - Simone Pifferi
- International School for Advanced Studies (SISSA), 34136, Trieste, Italy
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60126, Ancona, Italy
| | - Holger Flechsig
- WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, 920-1192, Kanazawa, Japan
| | - Melanie Arndt
- Department of Biochemistry, University of Zurich, 8057, Zurich, Switzerland
| | | | - Michael Di Palma
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60126, Ancona, Italy
| | - Shifeng Guo
- Shenzhen Key Laboratory of Smart Sensing and Intelligent Systems, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
- Guangdong Provincial Key Lab of Robotics and Intelligent System, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, 518055, China
| | - Horst Vogel
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, 518055, Shenzhen, China
- Institut des Sciences et Ingénierie Chimiques (ISIC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Anna Menini
- International School for Advanced Studies (SISSA), 34136, Trieste, Italy
| | - Clemens M Franz
- WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, 920-1192, Kanazawa, Japan
| | - Vincent Torre
- International School for Advanced Studies (SISSA), 34136, Trieste, Italy.
- Institute of Materials (ION-CNR), Area Science Park, Basovizza, 34149, Trieste, Italy.
- BIoValley Investments System and Solutions (BISS), 34148, Trieste, Italy.
| | - Arin Marchesi
- WPI Nano Life Science Institute, Kanazawa University, Kakuma-machi, 920-1192, Kanazawa, Japan.
- Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60126, Ancona, Italy.
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24
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Tsuji T. Subcellular distribution of membrane lipids revealed by freeze-fracture electron microscopy. Anat Sci Int 2024; 99:1-6. [PMID: 37314684 DOI: 10.1007/s12565-023-00731-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 05/30/2023] [Indexed: 06/15/2023]
Abstract
Cell membranes are composed of a large variety of lipids and proteins. While the localization and function of membrane proteins have been extensively investigated, the distribution of membrane lipids, especially in the non-cytoplasmic leaflet of organelle membranes, remains largely unknown. Fluorescent biosensors have been widely used to study membrane lipid distribution; however, they have some limitations. By utilizing the quick-freezing and freeze-fracture replica labeling electron microscopy technique, we can uncover the precise distribution of membrane lipids within cells and assess the function of lipid-transporting proteins. In this review, I summarize recent progress in analyzing intracellular lipid distribution by utilizing this method.
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Affiliation(s)
- Takuma Tsuji
- Laboratory of Molecular Cell Biology, Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo, 113-8421, Japan.
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25
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Nguyen DM, Chen TY. Structure and Function of Calcium-Activated Chloride Channels and Phospholipid Scramblases in the TMEM16 Family. Handb Exp Pharmacol 2024; 283:153-180. [PMID: 35792944 DOI: 10.1007/164_2022_595] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The transmembrane protein 16 (TMEM16) family consists of Ca2+-activated chloride channels and phospholipid scramblases. Ten mammalian TMEM16 proteins, TMEM16A-K (with no TMEM16I), and several non-mammalian TMEM16 proteins, such as afTMEM16 and nhTMEM16, have been discovered. All known TMEM16 proteins are homodimeric proteins containing two subunits. Each subunit consists of ten transmembrane helices with Ca2+-binding sites and a single ion-permeation/phospholipid transport pathway. The ion-permeation pathway and the phospholipid transport pathway of TMEM16 proteins have a wide intracellular vestibule, a narrow neck, and a smaller extracellular vestibule. Interestingly, the lining wall of the ion-permeation/phospholipid transport pathway may be formed, at least partially, by membrane phospholipids, though the degree of pore-wall forming by phospholipids likely varies among TMEM16 proteins. Thus, the biophysical properties and activation mechanisms of TMEM16 proteins could differ from each other accordingly. Here we review the current understanding of the structure and function of TMEM16 molecules.
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Affiliation(s)
- Dung Manh Nguyen
- Center for Neuroscience, University of California, Davis, CA, USA.
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Tsung-Yu Chen
- Department of Neurology, Center for Neuroscience, University of California, Davis, CA, USA.
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26
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Lam AKM, Dutzler R. Mechanistic basis of ligand efficacy in the calcium-activated chloride channel TMEM16A. EMBO J 2023; 42:e115030. [PMID: 37984335 PMCID: PMC10711664 DOI: 10.15252/embj.2023115030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 10/27/2023] [Accepted: 11/02/2023] [Indexed: 11/22/2023] Open
Abstract
Agonist binding in ligand-gated ion channels is coupled to structural rearrangements around the binding site, followed by the opening of the channel pore. In this process, agonist efficacy describes the equilibrium between open and closed conformations in a fully ligand-bound state. Calcium-activated chloride channels in the TMEM16 family are important sensors of intracellular calcium signals and are targets for pharmacological modulators, yet a mechanistic understanding of agonist efficacy has remained elusive. Using a combination of cryo-electron microscopy, electrophysiology, and autocorrelation analysis, we now show that agonist efficacy in the ligand-gated channel TMEM16A is dictated by the conformation of the pore-lining helix α6 around the Ca2+ -binding site. The closure of the binding site, which involves the formation of a π-helix below a hinge region in α6, appears to be coupled to the opening of the inner pore gate, thereby governing the channel's open probability and conductance. Our results provide a mechanism for agonist binding and efficacy and a structural basis for the design of potentiators and partial agonists in the TMEM16 family.
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Affiliation(s)
- Andy KM Lam
- Department of BiochemistryUniversity of ZurichZurichSwitzerland
| | - Raimund Dutzler
- Department of BiochemistryUniversity of ZurichZurichSwitzerland
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27
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Papadourakis M, Sinenka H, Matricon P, Hénin J, Brannigan G, Pérez-Benito L, Pande V, van Vlijmen H, de Graaf C, Deflorian F, Tresadern G, Cecchini M, Cournia Z. Alchemical Free Energy Calculations on Membrane-Associated Proteins. J Chem Theory Comput 2023; 19:7437-7458. [PMID: 37902715 PMCID: PMC11017255 DOI: 10.1021/acs.jctc.3c00365] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Indexed: 10/31/2023]
Abstract
Membrane proteins have diverse functions within cells and are well-established drug targets. The advances in membrane protein structural biology have revealed drug and lipid binding sites on membrane proteins, while computational methods such as molecular simulations can resolve the thermodynamic basis of these interactions. Particularly, alchemical free energy calculations have shown promise in the calculation of reliable and reproducible binding free energies of protein-ligand and protein-lipid complexes in membrane-associated systems. In this review, we present an overview of representative alchemical free energy studies on G-protein-coupled receptors, ion channels, transporters as well as protein-lipid interactions, with emphasis on best practices and critical aspects of running these simulations. Additionally, we analyze challenges and successes when running alchemical free energy calculations on membrane-associated proteins. Finally, we highlight the value of alchemical free energy calculations calculations in drug discovery and their applicability in the pharmaceutical industry.
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Affiliation(s)
- Michail Papadourakis
- Biomedical
Research Foundation, Academy of Athens, 4 Soranou Ephessiou, 11527 Athens, Greece
| | - Hryhory Sinenka
- Institut
de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, F-67083 Strasbourg Cedex, France
| | - Pierre Matricon
- Sosei
Heptares, Steinmetz Building,
Granta Park, Great Abington, Cambridge CB21 6DG, United
Kingdom
| | - Jérôme Hénin
- Laboratoire
de Biochimie Théorique UPR 9080, CNRS and Université Paris Cité, 75005 Paris, France
| | - Grace Brannigan
- Center
for Computational and Integrative Biology, Rutgers University−Camden, Camden, New Jersey 08103, United States of America
- Department
of Physics, Rutgers University−Camden, Camden, New Jersey 08102, United States
of America
| | - Laura Pérez-Benito
- CADD,
In Silico Discovery, Janssen Research &
Development, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Vineet Pande
- CADD,
In Silico Discovery, Janssen Research &
Development, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Herman van Vlijmen
- CADD,
In Silico Discovery, Janssen Research &
Development, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Chris de Graaf
- Sosei
Heptares, Steinmetz Building,
Granta Park, Great Abington, Cambridge CB21 6DG, United
Kingdom
| | - Francesca Deflorian
- Sosei
Heptares, Steinmetz Building,
Granta Park, Great Abington, Cambridge CB21 6DG, United
Kingdom
| | - Gary Tresadern
- CADD,
In Silico Discovery, Janssen Research &
Development, Turnhoutseweg 30, 2340 Beerse, Belgium
| | - Marco Cecchini
- Institut
de Chimie de Strasbourg, UMR7177, CNRS, Université de Strasbourg, F-67083 Strasbourg Cedex, France
| | - Zoe Cournia
- Biomedical
Research Foundation, Academy of Athens, 4 Soranou Ephessiou, 11527 Athens, Greece
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28
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Renne MF, Ernst R. Membrane homeostasis beyond fluidity: control of membrane compressibility. Trends Biochem Sci 2023; 48:963-977. [PMID: 37652754 PMCID: PMC10580326 DOI: 10.1016/j.tibs.2023.08.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 08/03/2023] [Accepted: 08/04/2023] [Indexed: 09/02/2023]
Abstract
Biomembranes are complex materials composed of lipids and proteins that compartmentalize biochemistry. They are actively remodeled in response to physical and metabolic cues, as well as during cell differentiation and stress. The concept of homeoviscous adaptation has become a textbook example of membrane responsiveness. Here, we discuss limitations and common misconceptions revolving around it. By highlighting key moments in the life cycle of a transmembrane protein, we illustrate that membrane thickness and a finely regulated membrane compressibility are crucial to facilitate proper membrane protein insertion, function, sorting, and inheritance. We propose that the unfolded protein response (UPR) provides a mechanism for endoplasmic reticulum (ER) membrane homeostasis by sensing aberrant transverse membrane stiffening and triggering adaptive responses that re-establish membrane compressibility.
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Affiliation(s)
- Mike F Renne
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany; PZMS, Center for Molecular Signaling, Medical Faculty, Saarland University, Homburg, Germany.
| | - Robert Ernst
- Medical Biochemistry and Molecular Biology, Medical Faculty, Saarland University, Homburg, Germany; PZMS, Center for Molecular Signaling, Medical Faculty, Saarland University, Homburg, Germany.
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29
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Wang Y, Kinoshita T. The role of lipid scramblases in regulating lipid distributions at cellular membranes. Biochem Soc Trans 2023; 51:1857-1869. [PMID: 37767549 DOI: 10.1042/bst20221455] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Revised: 09/12/2023] [Accepted: 09/19/2023] [Indexed: 09/29/2023]
Abstract
Glycerophospholipids, sphingolipids and cholesterol assemble into lipid bilayers that form the scaffold of cellular membranes, in which proteins are embedded. Membrane composition and membrane protein profiles differ between plasma and intracellular membranes and between the two leaflets of a membrane. Lipid distributions between two leaflets are mediated by lipid translocases, including flippases and scramblases. Flippases use ATP to catalyze the inward movement of specific lipids between leaflets. In contrast, bidirectional flip-flop movements of lipids across the membrane are mediated by scramblases in an ATP-independent manner. Scramblases have been implicated in disrupting the lipid asymmetry of the plasma membrane, protein glycosylation, autophagosome biogenesis, lipoprotein secretion, lipid droplet formation and communications between organelles. Although scramblases in plasma membranes were identified over 10 years ago, most progress about scramblases localized in intracellular membranes has been made in the last few years. Herein, we review the role of scramblases in regulating lipid distributions in cellular membranes, focusing primarily on intracellular membrane-localized scramblases.
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Affiliation(s)
- Yicheng Wang
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
- Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Beijing 100190, China
| | - Taroh Kinoshita
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka 565-0871, Japan
- WPI Immunology Frontier Research Center, Osaka University, Suita, Osaka 565-0871, Japan
- Center for Infectious Disease Education and Research, Osaka University, Suita, Osaka 565-0871, Japan
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30
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Zhang P, Maruoka M, Suzuki R, Katani H, Dou Y, Packwood DM, Kosako H, Tanaka M, Suzuki J. Extracellular calcium functions as a molecular glue for transmembrane helices to activate the scramblase Xkr4. Nat Commun 2023; 14:5592. [PMID: 37696806 PMCID: PMC10495444 DOI: 10.1038/s41467-023-40934-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 08/11/2023] [Indexed: 09/13/2023] Open
Abstract
The "eat me" signal, phosphatidylserine is exposed on the surface of dying cells by phospholipid scrambling. Previously, we showed that the Xkr family protein Xkr4 is activated by caspase-mediated cleavage and binding of the XRCC4 fragment. Here, we show that extracellular calcium is an additional factor needed to activate Xkr4. The constitutively active mutant of Xkr4 is found to induce phospholipid scrambling in an extracellular, but not intracellular, calcium-dependent manner. Importantly, other Xkr family members also require extracellular calcium for activation. Alanine scanning shows that D123 and D127 of TM1 and E310 of TM3 coordinate calcium binding. Moreover, lysine scanning demonstrates that the E310K mutation-mediated salt bridge between TM1 and TM3 bypasses the requirement of calcium. Cysteine scanning proves that disulfide bond formation between TM1 and TM3 also activates phospholipid scrambling without calcium. Collectively, this study shows that extracellular calcium functions as a molecular glue for TM1 and TM3 of Xkr proteins for activation, thus demonstrating a regulatory mechanism for multi-transmembrane region-containing proteins.
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Affiliation(s)
- Panpan Zhang
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Yoshida-Honmachi, Sakyoku, Kyoto, 606-8501, Japan
- Graduate School of Biostudies, Kyoto University, Konoe-cho, Yoshida, Sakyoku, Kyoto, 606-8501, Japan
| | - Masahiro Maruoka
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Yoshida-Honmachi, Sakyoku, Kyoto, 606-8501, Japan
- Center for Integrated Biosystems, Institute for Biomedical Sciences, Academia Sinica, Taipei, Taiwan
| | - Ryo Suzuki
- Center for Integrative Medicine and Physics (CiMPhy), Institute for Advanced Study, Kyoto University, Yoshida-Honmachi, Sakyoku, Kyoto, 606-8501, Japan
| | - Hikaru Katani
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Yoshida-Honmachi, Sakyoku, Kyoto, 606-8501, Japan
| | - Yu Dou
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Yoshida-Honmachi, Sakyoku, Kyoto, 606-8501, Japan
- Graduate School of Biostudies, Kyoto University, Konoe-cho, Yoshida, Sakyoku, Kyoto, 606-8501, Japan
| | - Daniel M Packwood
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Yoshida-Honmachi, Sakyoku, Kyoto, 606-8501, Japan
| | - Hidetaka Kosako
- Fujii Memorial Institute of Medical Sciences, Institute of Advanced Medical Sciences, Tokushima University, 3-18-15 Kuramoto-cho, Tokushima, 770-8503, Japan
| | - Motomu Tanaka
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Yoshida-Honmachi, Sakyoku, Kyoto, 606-8501, Japan
- Center for Integrative Medicine and Physics (CiMPhy), Institute for Advanced Study, Kyoto University, Yoshida-Honmachi, Sakyoku, Kyoto, 606-8501, Japan
- Physical Chemistry of Biosystems, Institute of Physical Chemistry, Heidelberg University, 69120, Heidelberg, Germany
| | - Jun Suzuki
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Yoshida-Honmachi, Sakyoku, Kyoto, 606-8501, Japan.
- Graduate School of Biostudies, Kyoto University, Konoe-cho, Yoshida, Sakyoku, Kyoto, 606-8501, Japan.
- Center for Integrated Biosystems, Institute for Biomedical Sciences, Academia Sinica, Taipei, Taiwan.
- CREST, Japan Science and Technology Agency, Kawaguchi, Saitama, 332-0012, Japan.
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31
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Li D, Rocha-Roa C, Schilling MA, Reinisch KM, Vanni S. Lipid scrambling is a general feature of protein insertases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.01.555937. [PMID: 37693532 PMCID: PMC10491306 DOI: 10.1101/2023.09.01.555937] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Glycerophospholipids are synthesized primarily in the cytosolic leaflet of the endoplasmic reticulum (ER) membrane and must be equilibrated between bilayer leaflets to allow the ER and membranes derived from it to grow. Lipid equilibration is facilitated by integral membrane proteins called "scramblases". These proteins feature a hydrophilic groove allowing the polar heads of lipids to traverse the hydrophobic membrane interior, similar to a credit-card moving through a reader. Nevertheless, despite their fundamental role in membrane expansion and dynamics, the identity of most scramblases has remained elusive. Here, combining biochemical reconstitution and molecular dynamics simulations, we show that lipid scrambling is a general feature of protein insertases, integral membrane proteins which insert polypeptide chains into membranes of the ER and organelles disconnected from vesicle trafficking. Our data indicate that lipid scrambling occurs in the same hydrophilic channel through which protein insertion takes place, and that scrambling is abolished in the presence of nascent polypeptide chains. We propose that protein insertases could have a so-far overlooked role in membrane dynamics as scramblases.
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Affiliation(s)
- Dazhi Li
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | | | - Matthew A. Schilling
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Karin M. Reinisch
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT, USA
| | - Stefano Vanni
- Department of Biology, University of Fribourg, Switzerland
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32
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Feng Z, Alvarenga OE, Accardi A. Structural basis of closed groove scrambling by a TMEM16 protein. RESEARCH SQUARE 2023:rs.3.rs-3256633. [PMID: 37645847 PMCID: PMC10462188 DOI: 10.21203/rs.3.rs-3256633/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Activation of Ca2+-dependent TMEM16 scramblases induces the externalization of phosphatidylserine, a key molecule in multiple signaling processes. Current models suggest that the TMEM16s scramble lipids by deforming the membrane near a hydrophilic groove, and that Ca2+ dependence arises from the different association of lipids with an open or closed groove. However, the molecular rearrangements involved in groove opening and of how lipids reorganize outside the closed groove remain unknown. Using cryogenic electron microscopy, we directly visualize how lipids associate at the closed groove of Ca2+-bound nhTMEM16 in nanodiscs. Functional experiments pinpoint the lipid-protein interaction sites critical for closed groove scrambling. Structural and functional analyses suggest groove opening entails the sequential appearance of two π-helical turns in the groove-lining TM6 helix and identify critical rearrangements. Finally, we show that the choice of scaffold protein and lipids affects the conformations of nhTMEM16 and their distribution, highlighting a key role of these factors in cryoEM structure determination.
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Affiliation(s)
- Zhang Feng
- Department of Anesthesiology, Weill Cornell Medical College
| | - Omar E. Alvarenga
- Physiology, Biophysics and Systems Biology Graduate Program, Weill Cornell Medical College
| | - Alessio Accardi
- Department of Anesthesiology, Weill Cornell Medical College
- Department of Physiology and Biophysics, Weill Cornell Medical College
- Department of Biochemistry, Weill Cornell Medical College
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33
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Feng S, Puchades C, Ko J, Wu H, Chen Y, Figueroa EE, Gu S, Han TW, Ho B, Cheng T, Li J, Shoichet B, Jan YN, Cheng Y, Jan LY. Identification of a drug binding pocket in TMEM16F calcium-activated ion channel and lipid scramblase. Nat Commun 2023; 14:4874. [PMID: 37573365 PMCID: PMC10423226 DOI: 10.1038/s41467-023-40410-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 07/23/2023] [Indexed: 08/14/2023] Open
Abstract
The dual functions of TMEM16F as Ca2+-activated ion channel and lipid scramblase raise intriguing questions regarding their molecular basis. Intrigued by the ability of the FDA-approved drug niclosamide to inhibit TMEM16F-dependent syncytia formation induced by SARS-CoV-2, we examined cryo-EM structures of TMEM16F with or without bound niclosamide or 1PBC, a known blocker of TMEM16A Ca2+-activated Cl- channel. Here, we report evidence for a lipid scrambling pathway along a groove harboring a lipid trail outside the ion permeation pore. This groove contains the binding pocket for niclosamide and 1PBC. Mutations of two residues in this groove specifically affect lipid scrambling. Whereas mutations of some residues in the binding pocket of niclosamide and 1PBC reduce their inhibition of TMEM16F-mediated Ca2+ influx and PS exposure, other mutations preferentially affect the ability of niclosamide and/or 1PBC to inhibit TMEM16F-mediated PS exposure, providing further support for separate pathways for ion permeation and lipid scrambling.
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Affiliation(s)
- Shengjie Feng
- Department of Physiology, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Cristina Puchades
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Juyeon Ko
- Department of Physiology, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Hao Wu
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Yifei Chen
- Howard Hughes Medical Institute; UCSF, San Francisco, CA, USA
| | - Eric E Figueroa
- Department of Physiology, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Shuo Gu
- BioDuro-Sundia Inc., Irvine, CA, USA
| | - Tina W Han
- Department of Physiology, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
- Dewpoint Therapeutics, Boston, MA, USA
| | - Brandon Ho
- Department of Physiology, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Tong Cheng
- Howard Hughes Medical Institute; UCSF, San Francisco, CA, USA
| | - Junrui Li
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
| | - Brian Shoichet
- Department of Pharmaceutical Chemistry, University of California San Francisco (UCSF) School of Pharmacy, San Francisco, CA, USA
| | - Yuh Nung Jan
- Department of Physiology, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA
- Howard Hughes Medical Institute; UCSF, San Francisco, CA, USA
| | - Yifan Cheng
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA.
- Howard Hughes Medical Institute; UCSF, San Francisco, CA, USA.
| | - Lily Yeh Jan
- Department of Physiology, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA.
- Department of Biochemistry and Biophysics, University of California San Francisco (UCSF) School of Medicine, San Francisco, CA, USA.
- Howard Hughes Medical Institute; UCSF, San Francisco, CA, USA.
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34
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Zhang M, Shan Y, Cox CD, Pei D. A mechanical-coupling mechanism in OSCA/TMEM63 channel mechanosensitivity. Nat Commun 2023; 14:3943. [PMID: 37402734 DOI: 10.1038/s41467-023-39688-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Accepted: 06/23/2023] [Indexed: 07/06/2023] Open
Abstract
Mechanosensitive (MS) ion channels are a ubiquitous type of molecular force sensor sensing forces from the surrounding bilayer. The profound structural diversity in these channels suggests that the molecular mechanisms of force sensing follow unique structural blueprints. Here we determine the structures of plant and mammalian OSCA/TMEM63 proteins, allowing us to identify essential elements for mechanotransduction and propose roles for putative bound lipids in OSCA/TMEM63 mechanosensation. Briefly, the central cavity created by the dimer interface couples each subunit and modulates dimeric OSCA/TMEM63 channel mechanosensitivity through the modulating lipids while the cytosolic side of the pore is gated by a plug lipid that prevents the ion permeation. Our results suggest that the gating mechanism of OSCA/TMEM63 channels may combine structural aspects of the 'lipid-gated' mechanism of MscS and TRAAK channels and the calcium-induced gating mechanism of the TMEM16 family, which may provide insights into the structural rearrangements of TMEM16/TMC superfamilies.
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Affiliation(s)
- Mingfeng Zhang
- Fudan University, Shanghai, 200433, China.
- Laboratory of Cell Fate Control, School of Life Sciences, Westlake University, Hangzhou, 310000, China.
| | - Yuanyue Shan
- Fudan University, Shanghai, 200433, China
- Laboratory of Cell Fate Control, School of Life Sciences, Westlake University, Hangzhou, 310000, China
| | - Charles D Cox
- Victor Chang Cardiac Research Institute, Sydney, 2010, Australia.
- School of Biomedical Sciences, Faculty of Medicine & Health, UNSW Sydney, Kensington, New South Wales, 2052, Australia.
| | - Duanqing Pei
- Laboratory of Cell Fate Control, School of Life Sciences, Westlake University, Hangzhou, 310000, China.
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Ning R, Pan S, Xiao D, Zheng Y, Zhang J. ANO10 is a potential prognostic biomarker and correlates with immune infiltration in breast cancer. Am J Cancer Res 2023; 13:1845-1862. [PMID: 37293146 PMCID: PMC10244099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 04/13/2023] [Indexed: 06/10/2023] Open
Abstract
Several diseases have been linked to the dysfunction of anoctamins. Anoctamins play a wide range of physiological roles, including cell proliferation, migration, epithelial secretion, and calcium-activated chloride channel activity. However, the function of anoctamin 10 (ANO10) in breast cancer is still unclear. ANO10 was highly expressed in bone marrow, blood, skin, adipose tissue, thyroid gland and salivary gland, while ANO10 was expressed at low levels in liver and skeletal muscle. Compared to benign breast lesions, the protein level of ANO10 was lower in malignant breast tumors. However, breast cancer patients with low ANO10 expression have favorable survival outcomes. ANO10 was negatively correlated with the infiltration of memory CD4 T cells, naïve B cells, CD8 T cells, chemokines and chemokine receptors. Furthermore, the ANO10 low expression group was more sensitive to certain chemotherapy drugs, including bleomycin, doxorubicin, gemcitabine, mitomycin and etoposide. Altogether, ANO10 is a potential biomarker that can effectively predict the prognosis of breast cancer. Our findings highlight the promising prognostic value and therapeutic target of ANO10 in breast cancer.
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Affiliation(s)
- Ran Ning
- Department of Pathology, The Affiliated Chaohu Hospital of Anhui Medical UniversityChaohu 238000, Anhui, China
| | - Shuaikang Pan
- Department of Medical Oncology, The First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of ChinaHefei 230000, Anhui, China
- School of Medical Oncology, Wan Nan Medical CollegeWuhu 241000, Anhui, China
| | - Dashu Xiao
- Department of Pathology, The Affiliated Chaohu Hospital of Anhui Medical UniversityChaohu 238000, Anhui, China
| | - Yan Zheng
- Department of Pathology, The Affiliated Chaohu Hospital of Anhui Medical UniversityChaohu 238000, Anhui, China
| | - Jinguo Zhang
- Department of Medical Oncology, The First Affiliated Hospital of USTC, Division of Life Science and Medicine, University of Science and Technology of ChinaHefei 230000, Anhui, China
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Sakuragi T, Nagata S. Regulation of phospholipid distribution in the lipid bilayer by flippases and scramblases. Nat Rev Mol Cell Biol 2023:10.1038/s41580-023-00604-z. [PMID: 37106071 PMCID: PMC10134735 DOI: 10.1038/s41580-023-00604-z] [Citation(s) in RCA: 49] [Impact Index Per Article: 49.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/09/2023] [Indexed: 04/29/2023]
Abstract
Cellular membranes function as permeability barriers that separate cells from the external environment or partition cells into distinct compartments. These membranes are lipid bilayers composed of glycerophospholipids, sphingolipids and cholesterol, in which proteins are embedded. Glycerophospholipids and sphingolipids freely move laterally, whereas transverse movement between lipid bilayers is limited. Phospholipids are asymmetrically distributed between membrane leaflets but change their location in biological processes, serving as signalling molecules or enzyme activators. Designated proteins - flippases and scramblases - mediate this lipid movement between the bilayers. Flippases mediate the confined localization of specific phospholipids (phosphatidylserine (PtdSer) and phosphatidylethanolamine) to the cytoplasmic leaflet. Scramblases randomly scramble phospholipids between leaflets and facilitate the exposure of PtdSer on the cell surface, which serves as an important signalling molecule and as an 'eat me' signal for phagocytes. Defects in flippases and scramblases cause various human diseases. We herein review the recent research on the structure of flippases and scramblases and their physiological roles. Although still poorly understood, we address the mechanisms by which they translocate phospholipids between lipid bilayers and how defects cause human diseases.
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Affiliation(s)
- Takaharu Sakuragi
- Biochemistry & Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan
| | - Shigekazu Nagata
- Biochemistry & Immunology, WPI Immunology Frontier Research Center, Osaka University, Osaka, Japan.
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37
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Yuan L, Tang Y, Yin L, Lin X, Luo Z, Wang S, Li J, Liang P, Jiang B. The role of Transmembrane Protein 16A (TMEM16A) in pulmonary hypertension. Cardiovasc Pathol 2023; 65:107525. [PMID: 36781068 DOI: 10.1016/j.carpath.2023.107525] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 02/04/2023] [Accepted: 02/06/2023] [Indexed: 02/13/2023] Open
Abstract
Transmembrane protein 16A (TMEM16A), a member of the TMEM16 family, is the molecular basis of Ca2+-activated chloride channels (CaCCs) and is involved in a variety of physiological and pathological processes. Previous studies have focused more on respiratory-related diseases and tumors. However, recent studies have identified an important role for TMEM16A in cardiovascular diseases, especially in pulmonary hypertension. TMEM16A is expressed in both pulmonary artery smooth muscle cells and pulmonary artery endothelial cells and is involved in the development of pulmonary hypertension. This paper presents the structure and function of TMEM16A, the pathogenesis of pulmonary hypertension, and highlights the role and mechanism of TMEM16A in pulmonary hypertension, summarizing the controversies in this field and taking into account hypertension and portal hypertension, which have similar pathogenesis. It is hoped that the unique role of TMEM16A in pulmonary hypertension will be illustrated and provide ideas for research in this area.
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Affiliation(s)
- Ludong Yuan
- Department of Pathophysiology, Sepsis Translational Medicine Key Laboratory of Hunan Province, Xiangya School of Medicine, Central South University, Changsha, Hunan, China; National Medicine Functional Experimental Teaching Center, Central South University, Changsha, Hunan China
| | - Yuting Tang
- Department of Pathophysiology, Sepsis Translational Medicine Key Laboratory of Hunan Province, Xiangya School of Medicine, Central South University, Changsha, Hunan, China; National Medicine Functional Experimental Teaching Center, Central South University, Changsha, Hunan China
| | - Leijing Yin
- Department of Pathophysiology, Sepsis Translational Medicine Key Laboratory of Hunan Province, Xiangya School of Medicine, Central South University, Changsha, Hunan, China; National Medicine Functional Experimental Teaching Center, Central South University, Changsha, Hunan China
| | - Xiaofang Lin
- Department of Pathophysiology, Sepsis Translational Medicine Key Laboratory of Hunan Province, Xiangya School of Medicine, Central South University, Changsha, Hunan, China; National Medicine Functional Experimental Teaching Center, Central South University, Changsha, Hunan China
| | - Zhengyang Luo
- Department of Pathophysiology, Sepsis Translational Medicine Key Laboratory of Hunan Province, Xiangya School of Medicine, Central South University, Changsha, Hunan, China; National Medicine Functional Experimental Teaching Center, Central South University, Changsha, Hunan China
| | - Shuxin Wang
- Department of Pathophysiology, Sepsis Translational Medicine Key Laboratory of Hunan Province, Xiangya School of Medicine, Central South University, Changsha, Hunan, China; National Medicine Functional Experimental Teaching Center, Central South University, Changsha, Hunan China
| | - Jing Li
- Department of Pathophysiology, Sepsis Translational Medicine Key Laboratory of Hunan Province, Xiangya School of Medicine, Central South University, Changsha, Hunan, China; National Medicine Functional Experimental Teaching Center, Central South University, Changsha, Hunan China
| | - Pengfei Liang
- Department of Burns and Plastic Surgery, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Bimei Jiang
- Department of Pathophysiology, Sepsis Translational Medicine Key Laboratory of Hunan Province, Xiangya School of Medicine, Central South University, Changsha, Hunan, China; National Medicine Functional Experimental Teaching Center, Central South University, Changsha, Hunan China.
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Massey S, Guo Y, Riley LG, Van Bergen NJ, Sandaradura SA, McCusker E, Tchan M, Thauvin-Robinet C, Thomas Q, Moreau T, Davis M, Smits D, Mancini GMS, Hakonarson H, Cooper S, Christodoulou J. Expanding the Allelic Heterogeneity of ANO10-Associated Autosomal Recessive Cerebellar Ataxia. Neurol Genet 2023; 9:e200051. [PMID: 36698452 PMCID: PMC9872716 DOI: 10.1212/nxg.0000000000200051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 11/15/2022] [Indexed: 01/24/2023]
Abstract
Background and Objectives The term autosomal recessive cerebellar ataxia (ARCA) encompasses a diverse group of heterogeneous degenerative disorders of the cerebellum. Spinocerebellar ataxia autosomal recessive 10 (SCAR10) is a distinct classification of cerebellar ataxia caused by variants in the ANO10 gene. Little is known about the molecular role of ANO10 or its role in disease. There is a wide phenotypic spectrum among patients, even among those with the same or similar genetic variants. This study aimed to characterize the molecular consequences of variants in ANO10 and determine their pathologic significance in patients diagnosed with SCAR10. Methods We presented 4 patients from 4 families diagnosed with spinocerebellar ataxia with potential pathogenic variants in the ANO10 gene. Patients underwent either clinical whole-exome sequencing or screening of a panel of known neuromuscular disease genes. Effects on splicing were studied using reverse transcriptase PCR to analyze complementary DNA. Western blots were used to examine protein expression. Results One individual who presented clinically at a much earlier age than typical was homozygous for an ANO10 variant (c.1864A > G [p.Met622Val]) that produces 2 transcription products by altering an exonic enhancer site. Two patients, both of Lebanese descent, had a homozygous intronic splicing variant in ANO10 (c.1163-9A > G) that introduced a cryptic splice site acceptor, producing 2 alternative transcription products and no detectable wild-type protein. Both these variants have not yet been associated with SCAR10. The remaining patient was found to have compound heterozygous variants in ANO10 previously associated with SCAR10 (c.132dupA [p.Asp45Argfs*9] and c.1537T > C [p.Cys513Arg]). Discussion We presented rare pathogenic variants adding to the growing list of ANO10 variants associated with SCAR10. In addition, we described an individual with a much earlier age at onset than usually associated with ANO10 variants. This expands the phenotypic and allelic heterogeneity of ANO10-associated ARCA.
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Affiliation(s)
- Sean Massey
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Yiran Guo
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Lisa G Riley
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Nicole J Van Bergen
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Sarah A Sandaradura
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Elizabeth McCusker
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Michel Tchan
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Christel Thauvin-Robinet
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Quentin Thomas
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Thibault Moreau
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Mark Davis
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Daphne Smits
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Grazia M S Mancini
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Hakon Hakonarson
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - Sandra Cooper
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
| | - John Christodoulou
- Brain and Mitochondrial Research Group (S.M., N.J.V.B., J.C.), Murdoch Children's Research Institute, Melbourne, VIC, Australia; Centre for Applied Genomics (Y.G., H.H.), Children's Hospital of Philadelphia, PA; Centre for Data Driven Discovery in Biomedicine (Y.G.), Children's Hospital of Philadelphia, PA; Rare Diseases Functional Genomics (L.G.R., S.C.), Kids Research, The Children's Hospital at Westmead and Children's Medical Research Institute, Sydney, NSW, Australia; Specialty of Child and Adolescent Health (L.G.R., S.C.), University of Sydney, NSW, Australia; Department of Paediatrics (N.J.V.B., J.C.), University of Melbourne, VIC, Australia; Department of Paediatrics and Child Health (S.A.S.), University of Sydney, NSW, Australia; Department of Clinical Genetics (S.A.S.), The Children's Hospital at Westmead, Sydney, NSW, Australia; Department of Genetic Medicine (M.T.), Westmead Hospital, Sydney, NSW, Australia; Department of Neurology (E.M.), Westmead Hospital, Sydney (NSW), Australia; Laboratory of Diagnostic Innovation in Rare Diseases (C.T.-R.), CHU Dijon Bourgogne, France; Genetics Center (C.T.-R.), CHU Dijon Bourgogne, France; Neurology (Q.T., T.M.), CHU Dijon Bourgogne, France; Diagnostics Genomics (M.D.), PathWest Laboratory Medicine, Perth, WA, Australia; and Department of Clinical Genetics (D.S., G.M.S.M.), ErasmusMC University Medical Center, Rotterdam, ZH, the Netherlands
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Overduin M, Tran A, Eekels DM, Overduin F, Kervin TA. Transmembrane Membrane Readers form a Novel Class of Proteins That Include Peripheral Phosphoinositide Recognition Domains and Viral Spikes. MEMBRANES 2022; 12:1161. [PMID: 36422153 PMCID: PMC9692390 DOI: 10.3390/membranes12111161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 11/11/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
Membrane proteins are broadly classified as transmembrane (TM) or peripheral, with functions that pertain to only a single bilayer at a given time. Here, we explicate a class of proteins that contain both transmembrane and peripheral domains, which we dub transmembrane membrane readers (TMMRs). Their transmembrane and peripheral elements anchor them to one bilayer and reversibly attach them to another section of bilayer, respectively, positioning them to tether and fuse membranes while recognizing signals such as phosphoinositides (PIs) and modifying lipid chemistries in proximity to their transmembrane domains. Here, we analyze full-length models from AlphaFold2 and Rosetta, as well as structures from nuclear magnetic resonance (NMR) spectroscopy and X-ray crystallography, using the Membrane Optimal Docking Area (MODA) program to map their membrane-binding surfaces. Eukaryotic TMMRs include phospholipid-binding C1, C2, CRAL-TRIO, FYVE, GRAM, GTPase, MATH, PDZ, PH, PX, SMP, StART and WD domains within proteins including protrudin, sorting nexins and synaptotagmins. The spike proteins of SARS-CoV-2 as well as other viruses are also TMMRs, seeing as they are anchored into the viral membrane while mediating fusion with host cell membranes. As such, TMMRs have key roles in cell biology and membrane trafficking, and include drug targets for diseases such as COVID-19.
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Affiliation(s)
- Michael Overduin
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | - Anh Tran
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | | | - Finn Overduin
- Institute of Nutritional Science, University of Potsdam, 14476 Potsdam, Germany
| | - Troy A. Kervin
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada
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40
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Chumpen Ramirez S, Gómez-Sánchez R, Verlhac P, Hardenberg R, Margheritis E, Cosentino K, Reggiori F, Ungermann C. --Atg9 interactions via its transmembrane domains are required for phagophore expansion during autophagy. Autophagy 2022:1-20. [PMID: 36354155 DOI: 10.1080/15548627.2022.2136340] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
During macroautophagy/autophagy, precursor cisterna known as phagophores expand and sequester portions of the cytoplasm and/or organelles, and subsequently close resulting in double-membrane transport vesicles called autophagosomes. Autophagosomes fuse with lysosomes/vacuoles to allow the degradation and recycling of their cargoes. We previously showed that sequential binding of yeast Atg2 and Atg18 to Atg9, the only conserved transmembrane protein in autophagy, at the extremities of the phagophore mediates the establishment of membrane contact sites between the phagophore and the endoplasmic reticulum. As the Atg2-Atg18 complex transfers lipids between adjacent membranes in vitro, it has been postulated that this activity and the scramblase activity of the trimers formed by Atg9 are required for the phagophore expansion. Here, we present evidence that Atg9 indeed promotes Atg2-Atg18 complex-mediated lipid transfer in vitro, although this is not the only requirement for its function in vivo. In particular, we show that Atg9 function is dramatically compromised by a F627A mutation within the conserved interface between the transmembrane domains of the Atg9 monomers. Although Atg9F627A self-interacts and binds to the Atg2-Atg18 complex, the F627A mutation blocks the phagophore expansion and thus autophagy progression. This phenotype is conserved because the corresponding human ATG9A mutant severely impairs autophagy as well. Importantly, Atg9F627A has identical scramblase activity in vitro like Atg9, and as with the wild-type protein enhances Atg2-Atg18-mediated lipid transfer. Collectively, our data reveal that interactions of Atg9 trimers via their transmembrane segments play a key role in phagophore expansion beyond Atg9's role as a lipid scramblase.Abbreviations: BafA1: bafilomycin A1; Cvt: cytoplasm-to-vacuole targeting; Cryo-EM: cryo-electron microscopy; ER: endoplasmic reticulum; GFP: green fluorescent protein; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MCS: membrane contact site; NBD-PE: N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine; PAS: phagophore assembly site; PE: phosphatidylethanolamine; prApe1: precursor Ape1; PtdIns3P: phosphatidylinositol-3-phosphate; SLB: supported lipid bilayer; SUV: small unilamellar vesicle; TMD: transmembrane domain; WT: wild type.
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Affiliation(s)
- Sabrina Chumpen Ramirez
- Osnabrück University, Department of Biology/Chemistry, Biochemistry section, Osnabrück, Germany
| | - Rubén Gómez-Sánchez
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Pauline Verlhac
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ralph Hardenberg
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | | | - Katia Cosentino
- Osnabrück University, Department of Biology/Chemistry, Osnabrück, Germany.,Center of Cellular Nanoanalytic Osnabrück (CellNanOs), Osnabrück University, Osnabrück, Germany
| | - Fulvio Reggiori
- Department of Biomedical Sciences of Cells and Systems, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.,Department of Biomedicine, Aarhus University, Ole Worms Alle 4, 8000 Aarhus C, Aarhus, Denmark.,Aarhus Institute of Advanced Studies (AIAS), Aarhus University, Aarhus C, Denmark
| | - Christian Ungermann
- Osnabrück University, Department of Biology/Chemistry, Biochemistry section, Osnabrück, Germany.,Center of Cellular Nanoanalytic Osnabrück (CellNanOs), Osnabrück University, Osnabrück, Germany
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41
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Arndt M, Alvadia C, Straub MS, Clerico Mosina V, Paulino C, Dutzler R. Structural basis for the activation of the lipid scramblase TMEM16F. Nat Commun 2022; 13:6692. [PMID: 36335104 PMCID: PMC9637102 DOI: 10.1038/s41467-022-34497-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022] Open
Abstract
TMEM16F, a member of the conserved TMEM16 family, plays a central role in the initiation of blood coagulation and the fusion of trophoblasts. The protein mediates passive ion and lipid transport in response to an increase in intracellular Ca2+. However, the mechanism of how the protein facilitates both processes has remained elusive. Here we investigate the basis for TMEM16F activation. In a screen of residues lining the proposed site of conduction, we identify mutants with strongly activating phenotype. Structures of these mutants determined herein by cryo-electron microscopy show major rearrangements leading to the exposure of hydrophilic patches to the membrane, whose distortion facilitates lipid diffusion. The concomitant opening of a pore promotes ion conduction in the same protein conformation. Our work has revealed a mechanism that is distinct for this branch of the family and that will aid the development of a specific pharmacology for a promising drug target.
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Affiliation(s)
- Melanie Arndt
- grid.7400.30000 0004 1937 0650Department of Biochemistry University of Zurich, Winterthurer Str. 190, CH-8057 Zurich, Switzerland
| | - Carolina Alvadia
- grid.7400.30000 0004 1937 0650Department of Biochemistry University of Zurich, Winterthurer Str. 190, CH-8057 Zurich, Switzerland
| | - Monique S. Straub
- grid.7400.30000 0004 1937 0650Department of Biochemistry University of Zurich, Winterthurer Str. 190, CH-8057 Zurich, Switzerland
| | - Vanessa Clerico Mosina
- grid.4830.f0000 0004 0407 1981Department of Structural Biology and Membrane Enzymology at the Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Cristina Paulino
- grid.4830.f0000 0004 0407 1981Department of Structural Biology and Membrane Enzymology at the Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Raimund Dutzler
- grid.7400.30000 0004 1937 0650Department of Biochemistry University of Zurich, Winterthurer Str. 190, CH-8057 Zurich, Switzerland
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Tang D, Wang Y, Dong X, Yuan Y, Kang F, Tian W, Wang K, Li H, Qi S. Scramblases and virus infection. Bioessays 2022; 44:e2100261. [DOI: 10.1002/bies.202100261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 09/26/2022] [Accepted: 09/27/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Dan Tang
- Department of Urology Institute of Urology (Laboratory of Reconstructive Urology) State Key Laboratory of Oral Disease West China Hospital of Stomatology West China Hospital Sichuan University Chengdu Sichuan China
| | - Yichang Wang
- Department of Urology Institute of Urology (Laboratory of Reconstructive Urology) State Key Laboratory of Oral Disease West China Hospital of Stomatology West China Hospital Sichuan University Chengdu Sichuan China
| | - Xiuju Dong
- Department of Urology Institute of Urology (Laboratory of Reconstructive Urology) State Key Laboratory of Oral Disease West China Hospital of Stomatology West China Hospital Sichuan University Chengdu Sichuan China
| | - Yiqiong Yuan
- Department of Urology Institute of Urology (Laboratory of Reconstructive Urology) State Key Laboratory of Oral Disease West China Hospital of Stomatology West China Hospital Sichuan University Chengdu Sichuan China
| | - Fanchen Kang
- Department of Urology Institute of Urology (Laboratory of Reconstructive Urology) State Key Laboratory of Oral Disease West China Hospital of Stomatology West China Hospital Sichuan University Chengdu Sichuan China
| | - Weidong Tian
- Department of Urology Institute of Urology (Laboratory of Reconstructive Urology) State Key Laboratory of Oral Disease West China Hospital of Stomatology West China Hospital Sichuan University Chengdu Sichuan China
| | - Kunjie Wang
- Department of Urology Institute of Urology (Laboratory of Reconstructive Urology) State Key Laboratory of Oral Disease West China Hospital of Stomatology West China Hospital Sichuan University Chengdu Sichuan China
| | - Hong Li
- Department of Urology Institute of Urology (Laboratory of Reconstructive Urology) State Key Laboratory of Oral Disease West China Hospital of Stomatology West China Hospital Sichuan University Chengdu Sichuan China
| | - Shiqian Qi
- Department of Urology Institute of Urology (Laboratory of Reconstructive Urology) State Key Laboratory of Oral Disease West China Hospital of Stomatology West China Hospital Sichuan University Chengdu Sichuan China
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43
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Kim H, Kim E, Lee BC. Investigation of Phosphatidylserine-Transporting Activity of Human TMEM16C Isoforms. MEMBRANES 2022; 12:1005. [PMID: 36295764 PMCID: PMC9611045 DOI: 10.3390/membranes12101005] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2022] [Revised: 10/13/2022] [Accepted: 10/14/2022] [Indexed: 06/16/2023]
Abstract
Lipid scrambling is a rapid process that dissipates the asymmetrical distribution of phospholipids in the plasma membrane. It is involved in various physiological functions such as blood coagulation and apoptosis. Many TMEM16 members are recognized as Ca2+-activated phospholipid scramblases, which transport phospholipids between the two leaflets of the plasma membrane nonspecifically and bidirectionally; among these, TMEM16C is abundant in the brain, especially in neuronal cells. We investigated the scrambling activity of three human TMEM16C isoforms with different N-terminus lengths. After optimizing conditions to minimize endogenous scrambling activity, an annexin V-based imaging assay was used to detect phosphatidylserine (PS) scrambling in 293T cells. Unlike previous results, our data showed that human TMEM16C isoform 1 and isoform 3 exposed PS to the cell surface. A surface biotinylation assay showed that the surface expression of isoform 2, which did not show scrambling activity, was ~5 times lower than the other isoforms. In contrast to other TMEM16 proteins, flux assays and electrophysiology recording showed TMEM16C does not possess ion-transporting activity. We conclude that the N-terminus of TMEM16C determines whether TMEM16C can translocate to the plasma membrane and facilitate scrambling activity; membrane-localized TMEM16C isoforms 1 and 3 transport PS to the outer leaflet.
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44
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Jia Z, Huang J, Chen J. Activation of TMEM16F by inner gate charged mutations and possible lipid/ion permeation mechanisms. Biophys J 2022; 121:3445-3457. [PMID: 35978550 PMCID: PMC9515230 DOI: 10.1016/j.bpj.2022.08.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 05/24/2022] [Accepted: 08/12/2022] [Indexed: 11/19/2022] Open
Abstract
Transmembrane protein 16F (TMEM16F) is a ubiquitously expressed Ca2+-activated phospholipid scramblase that also functions as a largely non-selective ion channel. Though recent structural studies have revealed the closed and intermediate conformations of mammalian TMEM16F (mTMEM16F), the open and conductive state remains elusive. Instead, it has been proposed that an open hydrophilic pathway may not be required for lipid scrambling. We previously identified an inner activation gate, consisting of F518, Y563, and I612, and showed that charged mutations of the inner gate residues led to constitutively active mTMEM16F scrambling. Herein, atomistic simulations show that lysine substitution of F518 and Y563 can indeed lead to spontaneous opening of the permeation pore in the Ca2+-bound state of mTMEM16F. Dilation of the pore exposes hydrophilic patches in the upper pore region, greatly increases the pore hydration level, and enables lipid scrambling. The putative open state of mTMEM16F resembles the active state of fungal scramblases and is a meta-stable state for the wild-type protein in the Ca2+-bound state. Therefore, mTMEM16F may be capable of supporting the canonical in-groove scrambling mechanism in addition to the out-of-groove one. Further analysis reveals that the in-groove phospholipid and ion transduction pathways of mTMEM16F overlap from the intracellular side up to the inner gate but diverge from each other with different exits to the extracellular side of membrane.
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Affiliation(s)
- Zhiguang Jia
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts
| | - Jian Huang
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts
| | - Jianhan Chen
- Department of Chemistry, University of Massachusetts, Amherst, Massachusetts; Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts.
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45
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Khelashvili G, Kots E, Cheng X, Levine MV, Weinstein H. The allosteric mechanism leading to an open-groove lipid conductive state of the TMEM16F scramblase. Commun Biol 2022; 5:990. [PMID: 36123525 PMCID: PMC9484709 DOI: 10.1038/s42003-022-03930-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 08/30/2022] [Indexed: 11/23/2022] Open
Abstract
TMEM16F is a Ca2+-activated phospholipid scramblase in the TMEM16 family of membrane proteins. Unlike other TMEM16s exhibiting a membrane-exposed hydrophilic groove that serves as a translocation pathway for lipids, the experimentally determined structures of TMEM16F shows the groove in a closed conformation even under conditions of maximal scramblase activity. It is currently unknown if/how TMEM16F groove can open for lipid scrambling. Here we describe the analysis of ~400 µs all-atom molecular dynamics (MD) simulations of the TMEM16F revealing an allosteric mechanism leading to an open-groove, lipid scrambling competent state of the protein. The groove opens into a continuous hydrophilic conduit that is highly similar in structure to that seen in other activated scramblases. The allosteric pathway connects this opening to an observed destabilization of the Ca2+ ion bound at the distal site near the dimer interface, to the dynamics of specific protein regions that produces the open-groove state to scramble phospholipids.
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Affiliation(s)
- George Khelashvili
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA.
- Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA.
| | - Ekaterina Kots
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Xiaolu Cheng
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Michael V Levine
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
- Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
| | - Harel Weinstein
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, 10065, USA
- Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, 10065, USA
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46
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Aida I, Ozawa T, Ohta K, Fujinaka H, Goto K, Nakajima T. Autosomal Recessive Spinocerebellar Ataxia Type 10: A Report of a New Case in Japan. Intern Med 2022; 61:2517-2521. [PMID: 35110481 PMCID: PMC9449628 DOI: 10.2169/internalmedicine.8608-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Autosomal recessive spinocerebellar ataxia of type 10 (SCAR10) is a very rare neurodegenerative disease caused by mutations in the TMEM16K (ANO10) gene. This disorder is characterized by slowly progressive cerebellar ataxia and pyramidal signs inconstantly associated with cognitive decline, polyneuropathy, epilepsy, and vesicorectal dysfunction. To date, more than 40 cases have been reported in Europe. In contrast, only three cases have been identified in Asian countries. We herein report the third Japanese case of SCAR10 harboring a novel homozygous deletion mutation (c.616delG, p.Glu206Lysfs*17). This case presented with adult-onset slowly progressive spastic ataxia with cerebellar atrophy and mild cognitive decline.
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Affiliation(s)
- Izumi Aida
- Department of Neurology, National Hospital Organization Niigata National Hospital, Japan
| | - Tetsuo Ozawa
- Department of Internal Medicine, National Hospital Organization Niigata National Hospital, Japan
- Department of Genetic Counseling, National Hospital Organization Niigata National Hospital, Japan
| | - Kentaro Ohta
- Department of Neurology, National Hospital Organization Niigata National Hospital, Japan
- Department of Genetic Counseling, National Hospital Organization Niigata National Hospital, Japan
| | - Hidehiko Fujinaka
- Department of Genetic Counseling, National Hospital Organization Niigata National Hospital, Japan
- Department of Pediatrics, National Hospital Organization Niigata National Hospital, Japan
- Department of Clinical Research, National Hospital Organization Niigata National Hospital, Japan
| | - Kiyoe Goto
- Department of Genetic Counseling, National Hospital Organization Niigata National Hospital, Japan
| | - Takashi Nakajima
- Department of Neurology, National Hospital Organization Niigata National Hospital, Japan
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Nakao H, Nakano M. Flip-Flop Promotion Mechanisms by Model Transmembrane Peptides. Chem Pharm Bull (Tokyo) 2022; 70:519-523. [DOI: 10.1248/cpb.c22-00133] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Hiroyuki Nakao
- Department of Biointerface Chemistry, Faculty of Pharmaceutical Sciences, University of Toyama
| | - Minoru Nakano
- Department of Biointerface Chemistry, Faculty of Pharmaceutical Sciences, University of Toyama
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Evolutionary history of metazoan TMEM16 family. Mol Phylogenet Evol 2022; 177:107595. [PMID: 35914647 DOI: 10.1016/j.ympev.2022.107595] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 07/16/2022] [Accepted: 07/26/2022] [Indexed: 11/22/2022]
Abstract
Most of Transmembrane protein 16 (TMEM16) proteins function as either a Ca2+-activated Cl- channel (CaCC) or phospholipid scramblase (CaPLSase) and play diverse physiological roles. It is well conserved in eukaryotes; however, the origin and evolution of different subfamilies in Metazoa are not yet understood. To uncover the evolutionary history of the TMEM16 family, we analyzed 398 proteins from 74 invertebrate species using evolutionary genomics. We found that the TMEM16C-F and J subfamilies are vertebrate-specific, but the TMEM16A/B, G, H, and K subfamilies are ancient and present in many, but not all metazoan species. The most ancient subfamilies in Metazoa, TMEM16L and M, are only maintained in limited species. TMEM16N and O are Cnidaria- and Ecdysozoa-specific subfamilies, respectively, and Ctenophora, Xenacoelomorpha, and Rotifera contain species-specific proteins. We also identified TMEM16 genes that are closely linked together in the genome, suggesting that they have been generated via recent gene duplication. The anoctamin domain structures of invertebrate-specific TMEM16 proteins predicted by AlphaFold2 contain conserved Ca2+-binding motifs and permeation pathways with either narrow or wide inner gates. The inner gate distance of TMEM16 protein may have frequently switched during metazoan evolution, and thus determined the function of the protein as either CaCC or CaPLSase. These results demonstrate that TMEM16 family has evolved by gene gain and loss in metazoans, and the genes have been generally under purifying selection to maintain protein structures and physiological functions.
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Rodriguez TC, Zhong L, Simpson H, Gleason E. Reduced Expression of TMEM16A Impairs Nitric Oxide-Dependent Cl− Transport in Retinal Amacrine Cells. Front Cell Neurosci 2022; 16:937060. [PMID: 35966201 PMCID: PMC9363626 DOI: 10.3389/fncel.2022.937060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 06/21/2022] [Indexed: 11/13/2022] Open
Abstract
Postsynaptic cytosolic Cl− concentration determines whether GABAergic and glycinergic synapses are inhibitory or excitatory. We have shown that nitric oxide (NO) initiates the release of Cl− from acidic internal stores into the cytosol of retinal amacrine cells (ACs) thereby elevating cytosolic Cl−. In addition, we found that cystic fibrosis transmembrane conductance regulator (CFTR) expression and Ca2+ elevations are necessary for the transient effects of NO on cytosolic Cl− levels, but the mechanism remains to be elucidated. Here, we investigated the involvement of TMEM16A as a possible link between Ca2+ elevations and cytosolic Cl− release. TMEM16A is a Ca2+-activated Cl− channel that is functionally coupled with CFTR in epithelia. Both proteins are also expressed in neurons. Based on this and its Ca2+ dependence, we test the hypothesis that TMEM16A participates in the NO-dependent elevation in cytosolic Cl− in ACs. Chick retina ACs express TMEM16A as shown by Western blot analysis, single-cell PCR, and immunocytochemistry. Electrophysiology experiments demonstrate that TMEM16A functions in amacrine cells. Pharmacological inhibition of TMEM16A with T16inh-AO1 reduces the NO-dependent Cl− release as indicated by the diminished shift in the reversal potential of GABAA receptor-mediated currents. We confirmed the involvement of TMEM16A in the NO-dependent Cl− release using CRISPR/Cas9 knockdown of TMEM16A. Two different modalities targeting the gene for TMEM16A (ANO1) were tested in retinal amacrine cells: an all-in-one plasmid vector and crRNA/tracrRNA/Cas9 ribonucleoprotein. The all-in-one CRISPR/Cas9 modality did not change the expression of TMEM16A protein and produced no change in the response to NO. However, TMEM16A-specific crRNA/tracrRNA/Cas9 ribonucleoprotein effectively reduces both TMEM16A protein levels and the NO-dependent shift in the reversal potential of GABA-gated currents. These results show that TMEM16A plays a role in the NO-dependent Cl− release from retinal ACs.
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Cheng X, Khelashvili G, Weinstein H. The permeation of potassium ions through the lipid scrambling path of the membrane protein nhTMEM16. Front Mol Biosci 2022; 9:903972. [PMID: 35942471 PMCID: PMC9356224 DOI: 10.3389/fmolb.2022.903972] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 06/29/2022] [Indexed: 11/13/2022] Open
Abstract
The TMEM16 family of transmembrane proteins includes Ca2+-activated phospholipid scramblases (PLS) that can also function as non-selective ion channels. Extensive structural and functional studies have established that a membrane-exposed hydrophilic groove in TMEM16 PLS can serve as a translocation pathway for lipids. However, it is still unclear how the TMEM16 PLS conduct ions. A “protein-delimited pore” model suggests that ions are translocated through a narrow opening of the groove region, which is not sufficiently wide to allow lipid movement, whereas a “proteolipidic pore” model envisions ions and lipids translocating through an open conformation of the groove. We investigated the dynamic path of potassium ion (K+) translocation that occurs when an open groove state of nhTMEM16 is obtained from long atomistic molecular dynamics (MD) simulations, and calculated the free energy profile of the ion movement through the groove with umbrella sampling methodology. The free energy profile identifies effects of specific interactions along the K+ permeation path. The same calculations were performed to investigate ion permeation through a groove closed to lipid permeation in the nhTMEM16 L302A mutant which exhibits a stable conformation of the groove that does not permit lipid scrambling. Our results identify structural and energy parameters that enable K+ permeation, and suggest that the presence of lipids in the nhTMEM16 groove observed in the simulations during scrambling or in/out diffusion, affect the efficiency of K+ permeation to various extents.
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Affiliation(s)
- Xiaolu Cheng
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, United States
| | - George Khelashvili
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, United States
- Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, United States
| | - Harel Weinstein
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, United States
- Institute for Computational Biomedicine, Weill Cornell Medicine, New York, NY, United States
- *Correspondence: Harel Weinstein,
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