1
|
Pathak A, Willis KG, Bankaitis VA, McDermott MI. Mammalian START-like phosphatidylinositol transfer proteins - Physiological perspectives and roles in cancer biology. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159529. [PMID: 38945251 DOI: 10.1016/j.bbalip.2024.159529] [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: 03/29/2024] [Revised: 06/09/2024] [Accepted: 06/25/2024] [Indexed: 07/02/2024]
Abstract
PtdIns and its phosphorylated derivatives, the phosphoinositides, are the biochemical components of a major pathway of intracellular signaling in all eukaryotic cells. These lipids are few in terms of cohort of unique positional isomers, and are quantitatively minor species of the bulk cellular lipidome. Nevertheless, phosphoinositides regulate an impressively diverse set of biological processes. It is from that perspective that perturbations in phosphoinositide-dependent signaling pathways are increasingly being recognized as causal foundations of many human diseases - including cancer. Although phosphatidylinositol transfer proteins (PITPs) are not enzymes, these proteins are physiologically significant regulators of phosphoinositide signaling. As such, PITPs are conserved throughout the eukaryotic kingdom. Their biological importance notwithstanding, PITPs remain understudied. Herein, we review current information regarding PITP biology primarily focusing on how derangements in PITP function disrupt key signaling/developmental pathways and are associated with a growing list of pathologies in mammals.
Collapse
Affiliation(s)
- Adrija Pathak
- Department of Cell Biology and Genetics, Texas A&M Health Science Center, College Station, Texas, 77843, USA; Department of Biochemistry & Biophysics, Texas A&M University, College Station, TX, 77843, USA
| | - Katelyn G Willis
- Department of Cell Biology and Genetics, Texas A&M Health Science Center, College Station, Texas, 77843, USA
| | - Vytas A Bankaitis
- Department of Cell Biology and Genetics, Texas A&M Health Science Center, College Station, Texas, 77843, USA; Department of Chemistry, Texas A&M University, College Station, Texas 77843 USA
| | - Mark I McDermott
- Department of Cell Biology and Genetics, Texas A&M Health Science Center, College Station, Texas, 77843, USA.
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Huang X, Lee S, Chen K, Kawaguchi R, Wiskow O, Ghosh S, Frost D, Perrault L, Pandey R, Klim JR, Boivin B, Hermawan C, Livak KJ, Geschwind DH, Wainger BJ, Eggan KC, Bean BP, Woolf CJ. Downregulation of the silent potassium channel Kv8.1 increases motor neuron vulnerability in amyotrophic lateral sclerosis. Brain Commun 2024; 6:fcae202. [PMID: 38911266 PMCID: PMC11191651 DOI: 10.1093/braincomms/fcae202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 04/10/2024] [Accepted: 06/07/2024] [Indexed: 06/25/2024] Open
Abstract
While voltage-gated potassium channels have critical roles in controlling neuronal excitability, they also have non-ion-conducting functions. Kv8.1, encoded by the KCNV1 gene, is a 'silent' ion channel subunit whose biological role is complex since Kv8.1 subunits do not form functional homotetramers but assemble with Kv2 to modify its ion channel properties. We profiled changes in ion channel expression in amyotrophic lateral sclerosis patient-derived motor neurons carrying a superoxide dismutase 1(A4V) mutation to identify what drives their hyperexcitability. A major change identified was a substantial reduction of KCNV1/Kv8.1 expression, which was also observed in patient-derived neurons with C9orf72 expansion. We then studied the effect of reducing KCNV1/Kv8.1 expression in healthy motor neurons and found it did not change neuronal firing but increased vulnerability to cell death. A transcriptomic analysis revealed dysregulated metabolism and lipid/protein transport pathways in KCNV1/Kv8.1-deficient motor neurons. The increased neuronal vulnerability produced by the loss of KCNV1/Kv8.1 was rescued by knocking down Kv2.2, suggesting a potential Kv2.2-dependent downstream mechanism in cell death. Our study reveals, therefore, unsuspected and distinct roles of Kv8.1 and Kv2.2 in amyotrophic lateral sclerosis-related neurodegeneration.
Collapse
Affiliation(s)
- Xuan Huang
- F.M. Kirby Neurobiology Research Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Seungkyu Lee
- F.M. Kirby Neurobiology Research Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Kuchuan Chen
- F.M. Kirby Neurobiology Research Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Riki Kawaguchi
- Department of Psychiatry and Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Ole Wiskow
- Department of Stem Cell and Regenerative Biology and Department of Molecular and Cellular Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Sulagna Ghosh
- Department of Stem Cell and Regenerative Biology and Department of Molecular and Cellular Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Devlin Frost
- F.M. Kirby Neurobiology Research Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Laura Perrault
- F.M. Kirby Neurobiology Research Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Roshan Pandey
- F.M. Kirby Neurobiology Research Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Joseph R Klim
- Department of Stem Cell and Regenerative Biology and Department of Molecular and Cellular Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Bruno Boivin
- F.M. Kirby Neurobiology Research Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Crystal Hermawan
- F.M. Kirby Neurobiology Research Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Kenneth J Livak
- Translational Immunogenomics Lab, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - Daniel H Geschwind
- Department of Psychiatry and Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Brian J Wainger
- Department of Neurology, Mass General Brigham and Harvard Medical School, Boston, MA 02114, USA
| | - Kevin C Eggan
- Department of Stem Cell and Regenerative Biology and Department of Molecular and Cellular Biology, Harvard Stem Cell Institute, Cambridge, MA 02138, USA
| | - Bruce P Bean
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - Clifford J Woolf
- F.M. Kirby Neurobiology Research Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
4
|
Cockcroft S. The expanding roles of PI4P and PI(4,5)P 2 at the plasma membrane: Role of phosphatidylinositol transfer proteins. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159394. [PMID: 37714261 DOI: 10.1016/j.bbalip.2023.159394] [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: 07/19/2023] [Revised: 08/31/2023] [Accepted: 09/05/2023] [Indexed: 09/17/2023]
Abstract
Phosphoinositides are phosphorylated derivatives of phosphatidylinositol, a phospholipid that is synthesised at the endoplasmic reticulum. The plasma membrane contains the enzymes to phosphorylate phosphatidylinositol and is therefore rich in the phosphorylated derivatives, PI4P and PI(4,5)P2. PI(4,5)P2 is a substrate for phospholipase C and during cell signaling, PI(4,5)P2 levels are reduced. Here I discuss a family of proteins, phosphatidylinositol transfer proteins (PITPs) that can restore PI(4,5)P2 levels.
Collapse
Affiliation(s)
- Shamshad Cockcroft
- Department of Neuroscience, Physiology and Pharmacology, Division of Biosciences, University College London, 21 University Street, London WC1E 6JJ, UK.
| |
Collapse
|
5
|
Ferns M, van der List D, Vierra NC, Lacey T, Murray K, Kirmiz M, Stewart RG, Sack JT, Trimmer JS. Electrically silent KvS subunits associate with native Kv2 channels in brain and impact diverse properties of channel function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.25.577135. [PMID: 38328147 PMCID: PMC10849721 DOI: 10.1101/2024.01.25.577135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Voltage-gated K+ channels of the Kv2 family are highly expressed in brain and play dual roles in regulating neuronal excitability and in organizing endoplasmic reticulum - plasma membrane (ER-PM) junctions. Studies in heterologous cells suggest that the two pore-forming alpha subunits Kv2.1 and Kv2.2 assemble with "electrically silent" KvS subunits to form heterotetrameric channels with distinct biophysical properties. Here, using mass spectrometry-based proteomics, we identified five KvS subunits as components of native Kv2.1 channels immunopurified from mouse brain, the most abundant being Kv5.1. We found that Kv5.1 co-immunoprecipitates with Kv2.1 and to a lesser extent with Kv2.2 from brain lysates, and that Kv5.1 protein levels are decreased by 70% in Kv2.1 knockout mice and 95% in Kv2.1/2.2 double knockout mice. Multiplex immunofluorescent labelling of rodent brain sections revealed that in neocortex Kv5.1 immunolabeling is apparent in a large percentage of Kv2.1 and Kv2.2-positive layer 2/3 neurons, and in a smaller percentage of layer 5 and 6 neurons. At the subcellular level, Kv5.1 is co-clustered with Kv2.1 and Kv2.2 at ER-PM junctions in cortical neurons, although clustering of Kv5.1-containing channels is reduced relative to homomeric Kv2 channels. We also found that in heterologous cells coexpression with Kv5.1 reduces the clustering and alters the pharmacological properties of Kv2.1 channels. Together, these findings demonstrate that the Kv5.1 electrically silent subunit is a component of a substantial fraction of native brain Kv2 channels, and that its incorporation into heteromeric channels can impact diverse aspects of Kv2 channel function.
Collapse
Affiliation(s)
- Michael Ferns
- Dept. of Anesthesiology and Pain Medicine, University of California Davis, One Shields Ave, Davis, CA 95616, USA
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Deborah van der List
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Nicholas C. Vierra
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Taylor Lacey
- Dept. of Anesthesiology and Pain Medicine, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Karl Murray
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
- Dept. of Psychiatry and Behavioral Sciences, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Michael Kirmiz
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Robert G. Stewart
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - Jon T. Sack
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| | - James S. Trimmer
- Dept. of Physiology and Membrane Biology, University of California Davis, One Shields Ave, Davis, CA 95616, USA
| |
Collapse
|
6
|
Sarhadi TR, Panse JS, Nagotu S. Mind the gap: Methods to study membrane contact sites. Exp Cell Res 2023; 431:113756. [PMID: 37633408 DOI: 10.1016/j.yexcr.2023.113756] [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: 03/28/2023] [Revised: 08/11/2023] [Accepted: 08/13/2023] [Indexed: 08/28/2023]
Abstract
Organelles are dynamic entities whose functions are essential for the optimum functioning of cells. It is now known that the juxtaposition of organellar membranes is essential for the exchange of metabolites and their communication. These functional apposition sites are termed membrane contact sites. Dynamic membrane contact sites between various sub-cellular structures such as mitochondria, endoplasmic reticulum, peroxisomes, Golgi apparatus, lysosomes, lipid droplets, plasma membrane, endosomes, etc. have been reported in various model systems. The burgeoning area of research on membrane contact sites has witnessed several manuscripts in recent years that identified the contact sites and components involved. Several methods have been developed to identify, measure and analyze the membrane contact sites. In this manuscript, we aim to discuss important methods developed to date that are used to study membrane contact sites.
Collapse
Affiliation(s)
- Tanveera Rounaque Sarhadi
- Organelle Biology and Cellular Ageing Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Janhavee Shirish Panse
- Organelle Biology and Cellular Ageing Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Shirisha Nagotu
- Organelle Biology and Cellular Ageing Lab, Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India.
| |
Collapse
|
7
|
Casas M, Murray KD, Hino K, Vierra NC, Simó S, Trimmer JS, Dixon RE, Dickson EJ. NPC1-dependent alterations in K V2.1-Ca V1.2 nanodomains drive neuronal death in models of Niemann-Pick Type C disease. Nat Commun 2023; 14:4553. [PMID: 37507375 PMCID: PMC10382591 DOI: 10.1038/s41467-023-39937-w] [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: 08/17/2022] [Accepted: 07/04/2023] [Indexed: 07/30/2023] Open
Abstract
Lysosomes communicate through cholesterol transfer at endoplasmic reticulum (ER) contact sites. At these sites, the Niemann Pick C1 cholesterol transporter (NPC1) facilitates the removal of cholesterol from lysosomes, which is then transferred to the ER for distribution to other cell membranes. Mutations in NPC1 result in cholesterol buildup within lysosomes, leading to Niemann-Pick Type C (NPC) disease, a progressive and fatal neurodegenerative disorder. The molecular mechanisms connecting NPC1 loss to NPC-associated neuropathology remain unknown. Here we show both in vitro and in an animal model of NPC disease that the loss of NPC1 function alters the distribution and activity of voltage-gated calcium channels (CaV). Underlying alterations in calcium channel localization and function are KV2.1 channels whose interactions drive calcium channel clustering to enhance calcium entry and fuel neurotoxic elevations in mitochondrial calcium. Targeted disruption of KV2-CaV interactions rescues aberrant CaV1.2 clustering, elevated mitochondrial calcium, and neurotoxicity in vitro. Our findings provide evidence that NPC is a nanostructural ion channel clustering disease, characterized by altered distribution and activity of ion channels at membrane contacts, which contribute to neurodegeneration.
Collapse
Affiliation(s)
- Maria Casas
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, CA, USA
| | - Karl D Murray
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, CA, USA
- Department of Psychiatry & Behavioral Sciences, School of Medicine, University of California, Davis, CA, USA
| | - Keiko Hino
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA, USA
| | - Nicholas C Vierra
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, CA, USA
| | - Sergi Simó
- Department of Cell Biology and Human Anatomy, School of Medicine, University of California, Davis, CA, USA
| | - James S Trimmer
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, CA, USA
| | - Rose E Dixon
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, CA, USA
| | - Eamonn J Dickson
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, CA, USA.
| |
Collapse
|
8
|
Maurya S, Mills RW, Kahnert K, Chiang DY, Bertoli G, Lundegaard PR, Duran MPH, Zhang M, Rothenberg E, George AL, MacRae CA, Delmar M, Lundby A. Outlining cardiac ion channel protein interactors and their signature in the human electrocardiogram. NATURE CARDIOVASCULAR RESEARCH 2023; 2:673-692. [PMID: 38666184 PMCID: PMC11041666 DOI: 10.1038/s44161-023-00294-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 05/31/2023] [Indexed: 04/28/2024]
Abstract
Protein-protein interactions are essential for normal cellular processes and signaling events. Defining these interaction networks is therefore crucial for understanding complex cellular functions and interpretation of disease-associated gene variants. We need to build a comprehensive picture of the interactions, their affinities and interdependencies in the specific organ to decipher hitherto poorly understood signaling mechanisms through ion channels. Here we report the experimental identification of the ensemble of protein interactors for 13 types of ion channels in murine cardiac tissue. Of these, we validated the functional importance of ten interactors on cardiac electrophysiology through genetic knockouts in zebrafish, gene silencing in mice, super-resolution microscopy and patch clamp experiments. Furthermore, we establish a computational framework to reconstruct human cardiomyocyte ion channel networks from deep proteome mapping of human heart tissue and human heart single-cell gene expression data. Finally, we integrate the ion channel interactome with human population genetics data to identify proteins that influence the electrocardiogram (ECG). We demonstrate that the combined channel network is enriched for proteins influencing the ECG, with 44% of the network proteins significantly associated with an ECG phenotype. Altogether, we define interactomes of 13 major cardiac ion channels, contextualize their relevance to human electrophysiology and validate functional roles of ten interactors, including two regulators of the sodium current (epsin-2 and gelsolin). Overall, our data provide a roadmap for our understanding of the molecular machinery that regulates cardiac electrophysiology.
Collapse
Affiliation(s)
- Svetlana Maurya
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Robert W. Mills
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Konstantin Kahnert
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - David Y. Chiang
- Cardiovascular Medicine Division, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA USA
| | - Giorgia Bertoli
- Division of Cardiology, NYU School of Medicine, New York, NY USA
| | - Pia R. Lundegaard
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | | | - Mingliang Zhang
- Division of Cardiology, NYU School of Medicine, New York, NY USA
| | - Eli Rothenberg
- Division of Pharmacology, NYU School of Medicine, New York, NY USA
| | - Alfred L. George
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL USA
| | - Calum A. MacRae
- Cardiovascular Medicine Division, Brigham and Women’s Hospital and Harvard Medical School, Boston, MA USA
| | - Mario Delmar
- Division of Cardiology, NYU School of Medicine, New York, NY USA
| | - Alicia Lundby
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
9
|
Vullhorst D, Bloom MS, Akella N, Buonanno A. ER-PM Junctions on GABAergic Interneurons Are Organized by Neuregulin 2/VAP Interactions and Regulated by NMDA Receptors. Int J Mol Sci 2023; 24:2908. [PMID: 36769244 PMCID: PMC9917868 DOI: 10.3390/ijms24032908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 01/24/2023] [Accepted: 01/27/2023] [Indexed: 02/05/2023] Open
Abstract
Neuregulins (NRGs) signal via ErbB receptors to regulate neural development, excitability, synaptic and network activity, and behaviors relevant to psychiatric disorders. Bidirectional signaling between NRG2/ErbB4 and NMDA receptors is thought to homeostatically regulate GABAergic interneurons in response to increased excitatory neurotransmission or elevated extracellular glutamate levels. Unprocessed proNRG2 forms discrete clusters on cell bodies and proximal dendrites that colocalize with the potassium channel Kv2.1 at specialized endoplasmic reticulum-plasma membrane (ER-PM) junctions, and NMDA receptor activation triggers rapid dissociation from ER-PM junctions and ectodomain shedding by ADAM10. Here, we elucidate the mechanistic basis of proNRG2 clustering at ER-PM junctions and its regulation by NMDA receptors. Importantly, we demonstrate that proNRG2 promotes the formation of ER-PM junctions by directly binding the ER-resident membrane tether VAP, like Kv2.1. The proNRG2 intracellular domain harbors two non-canonical, low-affinity sites that cooperatively mediate VAP binding. One of these is a cryptic and phosphorylation-dependent VAP binding motif that is dephosphorylated following NMDA receptor activation, thus revealing how excitatory neurotransmission promotes the dissociation of proNRG2 from ER-PM junctions. Therefore, proNRG2 and Kv2.1 can independently function as VAP-dependent organizers of neuronal ER-PM junctions. Based on these and prior studies, we propose that proNRG2 and Kv2.1 serve as co-regulated downstream effectors of NMDA receptors to homeostatically regulate GABAergic interneurons.
Collapse
Affiliation(s)
- Detlef Vullhorst
- Section on Molecular Neurobiology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD 20892, USA
| | | | | | | |
Collapse
|
10
|
Dickson EJ. Role of Lysosomal Cholesterol in Regulating PI(4,5)P 2-Dependent Ion Channel Function. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1422:193-215. [PMID: 36988882 DOI: 10.1007/978-3-031-21547-6_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Lysosomes are central regulators of cellular growth and signaling. Once considered the acidic garbage can of the cell, their ever-expanding repertoire of functions include the regulation of cell growth, gene regulation, metabolic signaling, cell migration, and cell death. In this chapter, we detail how another of the lysosome's crucial roles, cholesterol transport, plays a vital role in the control of ion channel function and neuronal excitability through its ability to influence the abundance of the plasma membrane signaling lipid phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). This chapter will introduce the biosynthetic pathways of cholesterol and PI(4,5)P2, discuss the molecular mechanisms through which each lipid distinctly regulates ion channels, and consider the interdependence of these lipids in the control of ion channel function.
Collapse
Affiliation(s)
- Eamonn J Dickson
- Department of Physiology and Membrane Biology, University of California, Davis, CA, USA.
| |
Collapse
|
11
|
Barman B, Sung BH, Krystofiak E, Ping J, Ramirez M, Millis B, Allen R, Prasad N, Chetyrkin S, Calcutt MW, Vickers K, Patton JG, Liu Q, Weaver AM. VAP-A and its binding partner CERT drive biogenesis of RNA-containing extracellular vesicles at ER membrane contact sites. Dev Cell 2022; 57:974-994.e8. [PMID: 35421371 PMCID: PMC9075344 DOI: 10.1016/j.devcel.2022.03.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Revised: 01/11/2022] [Accepted: 03/17/2022] [Indexed: 12/12/2022]
Abstract
RNA transfer via extracellular vesicles (EVs) influences cell phenotypes; however, lack of information regarding biogenesis of RNA-containing EVs has limited progress in the field. Here, we identify endoplasmic reticulum membrane contact sites (ER MCSs) as platforms for the generation of RNA-containing EVs. We identify a subpopulation of small EVs that is highly enriched in RNA and regulated by the ER MCS linker protein VAP-A. Functionally, VAP-A-regulated EVs are critical for miR-100 transfer between cells and in vivo tumor formation. Lipid analysis of VAP-A-knockdown EVs revealed reductions in the EV biogenesis lipid ceramide. Knockdown of the VAP-A-binding ceramide transfer protein CERT led to similar defects in EV RNA content. Imaging experiments revealed that VAP-A promotes luminal filling of multivesicular bodies (MVBs), CERT localizes to MVBs, and the ceramide-generating enzyme neutral sphingomyelinase 2 colocalizes with VAP-A-positive ER. We propose that ceramide transfer via VAP-A-CERT linkages drives the biogenesis of a select RNA-containing EV population.
Collapse
Affiliation(s)
- Bahnisikha Barman
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Bong Hwan Sung
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Evan Krystofiak
- Vanderbilt University Cell Imaging Shared Resource, Nashville, TN, USA
| | - Jie Ping
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Marisol Ramirez
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Bryan Millis
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Department of Biomedical Engineering, Vanderbilt Biophotonics Center, Vanderbilt School of Engineering, Nashville, TN, USA
| | - Ryan Allen
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Nripesh Prasad
- HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA
| | - Sergei Chetyrkin
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN, USA
| | - M Wade Calcutt
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN, USA; Department of Biochemistry, Vanderbilt University, Nashville, TN, USA
| | - Kasey Vickers
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - James G Patton
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA
| | - Qi Liu
- Department of Biostatistics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Alissa M Weaver
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA; Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA.
| |
Collapse
|
12
|
Byrne DJ, Garcia-Pardo ME, Cole NB, Batnasan B, Heneghan S, Sohail A, Blackstone C, O'Sullivan NC. Liver X receptor-agonist treatment rescues degeneration in a Drosophila model of hereditary spastic paraplegia. Acta Neuropathol Commun 2022; 10:40. [PMID: 35346366 PMCID: PMC8961908 DOI: 10.1186/s40478-022-01343-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/02/2022] [Indexed: 12/26/2022] Open
Abstract
Hereditary spastic paraplegias (HSPs) are a group of inherited, progressive neurodegenerative conditions characterised by prominent lower-limb spasticity and weakness, caused by a length-dependent degeneration of the longest corticospinal upper motor neurons. While more than 80 spastic paraplegia genes (SPGs) have been identified, many cases arise from mutations in genes encoding proteins which generate and maintain tubular endoplasmic reticulum (ER) membrane organisation. The ER-shaping proteins are essential for the health and survival of long motor neurons, however the mechanisms by which mutations in these genes cause the axonopathy observed in HSP have not been elucidated. To further develop our understanding of the ER-shaping proteins, this study outlines the generation of novel in vivo and in vitro models, using CRISPR/Cas9-mediated gene editing to knockout the ER-shaping protein ADP-ribosylation factor-like 6 interacting protein 1 (ARL6IP1), mutations in which give rise to the HSP subtype SPG61. Loss of Arl6IP1 in Drosophila results in progressive locomotor deficits, emulating a key aspect of HSP in patients. ARL6IP1 interacts with ER-shaping proteins and is required for regulating the organisation of ER tubules, particularly within long motor neuron axons. Unexpectedly, we identified physical and functional interactions between ARL6IP1 and the phospholipid transporter oxysterol-binding protein-related protein 8 in both human and Drosophila model systems, pointing to a conserved role for ARL6IP1 in lipid homeostasis. Furthermore, loss of Arl6IP1 from Drosophila neurons results in a cell non-autonomous accumulation of lipid droplets in axonal glia. Importantly, treatment with lipid regulating liver X receptor-agonists blocked lipid droplet accumulation, restored axonal ER organisation, and improved locomotor function in Arl6IP1 knockout Drosophila. Our findings indicate that disrupted lipid homeostasis contributes to neurodegeneration in HSP, identifying a potential novel therapeutic avenue for the treatment of this disorder.
Collapse
Affiliation(s)
- Dwayne J Byrne
- UCD School of Biomolecular and Biomedical Sciences, UCD Conway Institute, University College Dublin, Dublin 4, Ireland
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - M Elena Garcia-Pardo
- UCD School of Biomolecular and Biomedical Sciences, UCD Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Nelson B Cole
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Belguun Batnasan
- UCD School of Biomolecular and Biomedical Sciences, UCD Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Sophia Heneghan
- UCD School of Biomolecular and Biomedical Sciences, UCD Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Anood Sohail
- UCD School of Biomolecular and Biomedical Sciences, UCD Conway Institute, University College Dublin, Dublin 4, Ireland
| | - Craig Blackstone
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, 20892, USA
- MassGeneral Institute for Neurodegenerative Disease, Massachusetts General Hospital, Charlestown, MA, 02129, USA
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, 02114, USA
| | - Niamh C O'Sullivan
- UCD School of Biomolecular and Biomedical Sciences, UCD Conway Institute, University College Dublin, Dublin 4, Ireland.
| |
Collapse
|
13
|
Maverick EE, Tamkun MM. High spatial density is associated with non-conducting Kv channels from two families. Biophys J 2022; 121:755-768. [PMID: 35101417 PMCID: PMC8943702 DOI: 10.1016/j.bpj.2022.01.021] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 12/14/2021] [Accepted: 01/25/2022] [Indexed: 11/02/2022] Open
Abstract
Ion channels are well known for their ability to regulate the cell membrane potential. However, many ion channels also have functions that do not involve ion conductance. Kv2 channels are one family of ion channels whose non-conducting functions are central to mammalian cell physiology. Kv2.1 and Kv2.2 channels form stable contact sites between the endoplasmic reticulum and plasma membrane via an interaction with endoplasmic reticulum resident proteins. To perform this structural role, Kv2 channels are expressed at extremely high densities on the plasma membranes of many cell types, including central pyramidal neurons, α-motoneurons, and smooth muscle cells. Research from our lab and others has shown that the majority of these plasma membrane Kv2.1 channels do not conduct potassium in response to depolarization. The mechanism of this channel silencing is unknown but is thought to be dependent on channel density in the membrane. Furthermore, the prevalence of a non-conducting population of Kv2.2 channels has not been directly tested. In this work we make improved measurements of the numbers of conducting and non-conducting Kv2.1 channels expressed in HEK293 cells and expand the investigation of non-conducting channels to three additional Kv α-subunits: Kv2.2, Kv1.4, and Kv1.5. By comparing the numbers of gating and conducting channels in individual HEK293 cells, we found that on average, only 50% of both Kv2.1 and Kv2.2 channels conducted potassium and, as previously suggested, that fraction decreased with increased channel density in the plasma membrane. At the highest spatial densities tested, which are comparable with those found at Kv2 clusters in situ, only 20% of Kv2.1 and Kv2.2 channels conducted potassium. We also show for the first time that Kv1.4 and Kv1.5 exhibit density-dependent silencing, suggesting that this phenomenon has an underlying mechanism that is shared by Kv channels from multiple families.
Collapse
Affiliation(s)
- Emily E. Maverick
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado,Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, Colorado
| | - Michael M. Tamkun
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado,Molecular, Cellular and Integrative Neuroscience Program, Colorado State University, Fort Collins, Colorado,Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado,Corresponding author
| |
Collapse
|
14
|
Dickson EJ. Phosphoinositide transport and metabolism at membrane contact sites. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159107. [PMID: 34995791 PMCID: PMC9662651 DOI: 10.1016/j.bbalip.2021.159107] [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: 06/30/2021] [Revised: 12/06/2021] [Accepted: 12/09/2021] [Indexed: 11/18/2022]
Abstract
Phosphoinositides are a family of signaling lipids that play a profound role in regulating protein function at the membrane-cytosol interface of all cellular membranes. Underscoring their importance, mutations or alterations in phosphoinositide metabolizing enzymes lead to host of developmental, neurodegenerative, and metabolic disorders that are devastating for human health. In addition to lipid enzymes, phosphoinositide metabolism is regulated and controlled at membrane contact sites (MCS). Regions of close opposition typically between the ER and other cellular membranes, MCS are non-vesicular lipid transport portals that engage in extensive communication to influence organelle homeostasis. This review focuses on lipid transport, specifically phosphoinositide lipid transport and metabolism at MCS.
Collapse
Affiliation(s)
- Eamonn J Dickson
- Department of Physiology and Membrane Biology, University of California, Davis, CA 95616, United States of America.
| |
Collapse
|
15
|
Kors S, Costello JL, Schrader M. VAP Proteins - From Organelle Tethers to Pathogenic Host Interactors and Their Role in Neuronal Disease. Front Cell Dev Biol 2022; 10:895856. [PMID: 35756994 PMCID: PMC9213790 DOI: 10.3389/fcell.2022.895856] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 04/25/2022] [Indexed: 12/26/2022] Open
Abstract
Vesicle-associated membrane protein (VAMP)-associated proteins (VAPs) are ubiquitous ER-resident tail-anchored membrane proteins in eukaryotic cells. Their N-terminal major sperm protein (MSP) domain faces the cytosol and allows them to interact with a wide variety of cellular proteins. Therefore, VAP proteins are vital to many cellular processes, including organelle membrane tethering, lipid transfer, autophagy, ion homeostasis and viral defence. Here, we provide a timely overview of the increasing number of VAPA/B binding partners and discuss the role of VAPA/B in maintaining organelle-ER interactions and cooperation. Furthermore, we address how viruses and intracellular bacteria hijack VAPs and their binding partners to induce interactions between the host ER and pathogen-containing compartments and support pathogen replication. Finally, we focus on the role of VAP in human disease and discuss how mutated VAPB leads to the disruption of cellular homeostasis and causes amyotrophic lateral sclerosis.
Collapse
Affiliation(s)
- Suzan Kors
- *Correspondence: Suzan Kors, ; Michael Schrader,
| | | | | |
Collapse
|
16
|
Thapa P, Stewart R, Sepela RJ, Vivas O, Parajuli LK, Lillya M, Fletcher-Taylor S, Cohen BE, Zito K, Sack JT. EVAP: A two-photon imaging tool to study conformational changes in endogenous Kv2 channels in live tissues. J Gen Physiol 2021; 153:212666. [PMID: 34581724 PMCID: PMC8480965 DOI: 10.1085/jgp.202012858] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 09/03/2021] [Indexed: 12/29/2022] Open
Abstract
A primary goal of molecular physiology is to understand how conformational changes of proteins affect the function of cells, tissues, and organisms. Here, we describe an imaging method for measuring the conformational changes of the voltage sensors of endogenous ion channel proteins within live tissue, without genetic modification. We synthesized GxTX-594, a variant of the peptidyl tarantula toxin guangxitoxin-1E, conjugated to a fluorophore optimal for two-photon excitation imaging through light-scattering tissue. We term this tool EVAP (Endogenous Voltage-sensor Activity Probe). GxTX-594 targets the voltage sensors of Kv2 proteins, which form potassium channels and plasma membrane–endoplasmic reticulum junctions. GxTX-594 dynamically labels Kv2 proteins on cell surfaces in response to voltage stimulation. To interpret dynamic changes in fluorescence intensity, we developed a statistical thermodynamic model that relates the conformational changes of Kv2 voltage sensors to degree of labeling. We used two-photon excitation imaging of rat brain slices to image Kv2 proteins in neurons. We found puncta of GxTX-594 on hippocampal CA1 neurons that responded to voltage stimulation and retain a voltage response roughly similar to heterologously expressed Kv2.1 protein. Our findings show that EVAP imaging methods enable the identification of conformational changes of endogenous Kv2 voltage sensors in tissue.
Collapse
Affiliation(s)
- Parashar Thapa
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA
| | - Robert Stewart
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA
| | - Rebecka J Sepela
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA
| | - Oscar Vivas
- Center for Neuroscience, University of California, Davis, Davis, CA
| | - Laxmi K Parajuli
- Center for Neuroscience, University of California, Davis, Davis, CA
| | - Mark Lillya
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA
| | - Sebastian Fletcher-Taylor
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA.,The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Bruce E Cohen
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA.,Division of Molecular Biophysics and Integrated Bioimaging, Lawrence Berkeley National Laboratory, Berkeley, CA
| | - Karen Zito
- Center for Neuroscience, University of California, Davis, Davis, CA
| | - Jon T Sack
- Department of Physiology and Membrane Biology, University of California, Davis, Davis, CA.,Department of Anesthesiology and Pain Medicine, University of California, Davis, Davis, CA
| |
Collapse
|
17
|
Sun J, Harion R, Naito T, Saheki Y. INPP5K and Atlastin-1 maintain the nonuniform distribution of ER-plasma membrane contacts in neurons. Life Sci Alliance 2021; 4:4/11/e202101092. [PMID: 34556534 PMCID: PMC8507493 DOI: 10.26508/lsa.202101092] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 09/03/2021] [Accepted: 09/11/2021] [Indexed: 02/04/2023] Open
Abstract
In neurons, the ER extends throughout all cellular processes, forming multiple contacts with the plasma membrane (PM) to fine-tune neuronal physiology. However, the mechanisms that regulate the distribution of neuronal ER-PM contacts are not known. Here, we used the Caenorhabditis elegans DA9 motor neuron as our model system and found that neuronal ER-PM contacts are enriched in soma and dendrite and mostly absent in axons. Using forward genetic screen, we identified that the inositol 5-phosphatase, CIL-1 (human INPP5K), and the dynamin-like GTPase, ATLN-1 (human Atlastin-1), help to maintain the non-uniform, somatodendritic enrichment of neuronal ER-PM contacts. Mechanistically, CIL-1 acts upstream of ATLN-1 to maintain the balance between ER tubules and sheets. In mutants of CIL-1 or ATLN-1, ER sheets expand and invade into the axon. This is accompanied by the ectopic formation of axonal ER-PM contacts and defects in axon regeneration following laser-induced axotomy. As INPP5K and Atlastin-1 have been linked to neurological disorders, the unique distribution of neuronal ER-PM contacts maintained by these proteins may support neuronal resilience during the onset and progression of these diseases.
Collapse
Affiliation(s)
- Jingbo Sun
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Raihanah Harion
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Tomoki Naito
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore
| | - Yasunori Saheki
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore .,Department of Molecular Physiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| |
Collapse
|
18
|
de la Mora E, Dezi M, Di Cicco A, Bigay J, Gautier R, Manzi J, Polidori J, Castaño-Díez D, Mesmin B, Antonny B, Lévy D. Nanoscale architecture of a VAP-A-OSBP tethering complex at membrane contact sites. Nat Commun 2021; 12:3459. [PMID: 34103503 PMCID: PMC8187361 DOI: 10.1038/s41467-021-23799-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Accepted: 05/12/2021] [Indexed: 02/05/2023] Open
Abstract
Membrane contact sites (MCS) are subcellular regions where two organelles appose their membranes to exchange small molecules, including lipids. Structural information on how proteins form MCS is scarce. We designed an in vitro MCS with two membranes and a pair of tethering proteins suitable for cryo-tomography analysis. It includes VAP-A, an ER transmembrane protein interacting with a myriad of cytosolic proteins, and oxysterol-binding protein (OSBP), a lipid transfer protein that transports cholesterol from the ER to the trans Golgi network. We show that VAP-A is a highly flexible protein, allowing formation of MCS of variable intermembrane distance. The tethering part of OSBP contains a central, dimeric, and helical T-shape region. We propose that the molecular flexibility of VAP-A enables the recruitment of partners of different sizes within MCS of adjustable thickness, whereas the T geometry of the OSBP dimer facilitates the movement of the two lipid-transfer domains between membranes.
Collapse
Affiliation(s)
- Eugenio de la Mora
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, Paris, France
- Sorbonne Université, Paris, France
| | - Manuela Dezi
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, Paris, France.
- Sorbonne Université, Paris, France.
| | - Aurélie Di Cicco
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, Paris, France
- Sorbonne Université, Paris, France
| | - Joëlle Bigay
- CNRS UMR 7275, Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
| | - Romain Gautier
- CNRS UMR 7275, Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
| | - John Manzi
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, Paris, France
- Sorbonne Université, Paris, France
| | - Joël Polidori
- CNRS UMR 7275, Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
| | | | - Bruno Mesmin
- CNRS UMR 7275, Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France
| | - Bruno Antonny
- CNRS UMR 7275, Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, Valbonne, France.
| | - Daniel Lévy
- Laboratoire Physico Chimie Curie, Institut Curie, PSL Research University, CNRS UMR168, Paris, France.
- Sorbonne Université, Paris, France.
| |
Collapse
|
19
|
Venditti R, Wilson C, De Matteis MA. Regulation and physiology of membrane contact sites. Curr Opin Cell Biol 2021; 71:148-157. [PMID: 33932623 DOI: 10.1016/j.ceb.2021.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 03/18/2021] [Accepted: 03/22/2021] [Indexed: 12/14/2022]
Abstract
Membrane contact sites (MCSs) in addition to impacting the functions of membrane-limited organelles also have a role in the spatial and functional organization of cells, tissues and whole organisms. MCSs have been identified between all organelles and the identification of their molecular composition has progressed significantly in recent years. Equally important is how MCSs respond dynamically to physiological stimuli, how this is regulated, and the physiological roles of MCSs in tissues and at the organismal level, an area that still remains relatively unexplored. In the present review, we focus on the regulation of MCSs, considerations of their function at the organismal level, and how mutations of MCS components linked to genetic diseases might inform us about their physiological relevance.
Collapse
Affiliation(s)
- Rossella Venditti
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy; Department of Molecular Medicine and Medical Biotechnology, University of Napoli Federico II-Medical School, Naples, Italy
| | - Cathal Wilson
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy
| | - Maria Antonietta De Matteis
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy; Department of Molecular Medicine and Medical Biotechnology, University of Napoli Federico II-Medical School, Naples, Italy.
| |
Collapse
|
20
|
Hewlett B, Singh NP, Vannier C, Galli T. ER-PM Contact Sites - SNARING Actors in Emerging Functions. Front Cell Dev Biol 2021; 9:635518. [PMID: 33681218 PMCID: PMC7928305 DOI: 10.3389/fcell.2021.635518] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 01/21/2021] [Indexed: 11/13/2022] Open
Abstract
The compartmentalisation achieved by confining cytoplasm into membrane-enclosed organelles in eukaryotic cells is essential for maintaining vital functions including ATP production, synthetic and degradative pathways. While intracellular organelles are highly specialised in these functions, the restricting membranes also impede exchange of molecules responsible for the synchronised and responsive cellular activities. The initial identification of contact sites between the ER and plasma membrane (PM) provided a potential candidate structure for communication between organelles without mixing by fusion. Over the past decades, research has revealed a far broader picture of the events. Membrane contact sites (MCSs) have been recognized as increasingly important actors in cell differentiation, plasticity and maintenance, and, upon dysfunction, responsible for pathological conditions such as cancer and neurodegenerative diseases. Present in multiple organelles and cell types, MCSs promote transport of lipids and Ca2+ homoeostasis, with a range of associated protein families. Interestingly, each MCS displays a unique molecular signature, adapted to organelle functions. This review will explore the literature describing the molecular components and interactions taking place at ER-PM contact sites, their functions, and implications in eukaryotic cells, particularly neurons, with emphasis on lipid transfer proteins and emerging function of SNAREs.
Collapse
Affiliation(s)
- Bailey Hewlett
- INSERM U1266, Institut de Psychiatrie et Neurosciences de Paris, Université de Paris, Paris, France
| | - Neha Pratap Singh
- INSERM U1266, Institut de Psychiatrie et Neurosciences de Paris, Université de Paris, Paris, France
| | - Christian Vannier
- INSERM U1266, Institut de Psychiatrie et Neurosciences de Paris, Université de Paris, Paris, France
| | - Thierry Galli
- INSERM U1266, Institut de Psychiatrie et Neurosciences de Paris, Université de Paris, Paris, France.,GHU PARIS Psychiatrie and Neurosciences, Paris, France
| |
Collapse
|
21
|
Li C, Qian T, He R, Wan C, Liu Y, Yu H. Endoplasmic Reticulum-Plasma Membrane Contact Sites: Regulators, Mechanisms, and Physiological Functions. Front Cell Dev Biol 2021; 9:627700. [PMID: 33614657 PMCID: PMC7889955 DOI: 10.3389/fcell.2021.627700] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 01/13/2021] [Indexed: 12/13/2022] Open
Abstract
The endoplasmic reticulum (ER) forms direct membrane contact sites with the plasma membrane (PM) in eukaryotic cells. These ER-PM contact sites play essential roles in lipid homeostasis, ion dynamics, and cell signaling, which are carried out by protein-protein or protein-lipid interactions. Distinct tethering factors dynamically control the architecture of ER-PM junctions in response to intracellular signals or external stimuli. The physiological roles of ER-PM contact sites are dependent on a variety of regulators that individually or cooperatively perform functions in diverse cellular processes. This review focuses on proteins functioning at ER-PM contact sites and highlights the recent progress in their mechanisms and physiological roles.
Collapse
Affiliation(s)
- Chenlu Li
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Tiantian Qian
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Ruyue He
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Chun Wan
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO, United States
| | - Yinghui Liu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Haijia Yu
- Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing, China
| |
Collapse
|
22
|
Lin S, Meng T, Huang H, Zhuang H, He Z, Yang H, Feng D. Molecular machineries and physiological relevance of ER-mediated membrane contacts. Theranostics 2021; 11:974-995. [PMID: 33391516 PMCID: PMC7738843 DOI: 10.7150/thno.51871] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 10/22/2020] [Indexed: 02/06/2023] Open
Abstract
Membrane contact sites (MCSs) are defined as regions where two organelles are closely apposed, and most MCSs associated with each other via protein-protein or protein-lipid interactions. A number of key molecular machinery systems participate in mediating substance exchange and signal transduction, both of which are essential processes in terms of cellular physiology and pathophysiology. The endoplasmic reticulum (ER) is the largest reticulum network within the cell and has extensive communication with other cellular organelles, including the plasma membrane (PM), mitochondria, Golgi, endosomes and lipid droplets (LDs). The contacts and reactions between them are largely mediated by various protein tethers and lipids. Ions, lipids and even proteins can be transported between the ER and neighboring organelles or recruited to the contact site to exert their functions. This review focuses on the key molecules involved in the formation of different contact sites as well as their biological functions.
Collapse
Affiliation(s)
- Shiyin Lin
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Guangzhou Medical University, 511436, Guangzhou, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, 511436, Guangzhou, China
| | - Tian Meng
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Guangzhou Medical University, 511436, Guangzhou, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, 511436, Guangzhou, China
| | - Haofeng Huang
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Guangzhou Medical University, 511436, Guangzhou, China
| | - Haixia Zhuang
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Guangzhou Medical University, 511436, Guangzhou, China
| | - Zhengjie He
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Guangzhou Medical University, 511436, Guangzhou, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, 511436, Guangzhou, China
| | - Huan Yang
- Department of Pulmonary and Critical Care Medicine, Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University, Changsha 410021, China
| | - Du Feng
- Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou Municipal and Guangdong Provincial Key Laboratory of Protein Modification and Degradation, School of Basic Medical Sciences, Guangzhou Medical University, 511436, Guangzhou, China
- State Key Laboratory of Respiratory Disease, Guangzhou Medical University, 511436, Guangzhou, China
| |
Collapse
|
23
|
Balla T, Gulyas G, Kim YJ, Pemberton J. PHOSPHOINOSITIDES AND CALCIUM SIGNALING. A MARRIAGE ARRANGED IN ER-PM CONTACT SITES. CURRENT OPINION IN PHYSIOLOGY 2020; 17:149-157. [PMID: 32944676 DOI: 10.1016/j.cophys.2020.08.007] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Calcium (Ca2+) ions are critically important in orchestrating countless regulatory processes in eukaryotic cells. Consequently, cells tightly control cytoplasmic Ca2+ concentrations using a complex array of Ca2+-selective ion channels, transporters, and signaling effectors. Ca2+ transport through various cellular membranes is highly dependent on the intrinsic properties of specific membrane compartments and conversely, local Ca2+ changes have profound effects on the membrane lipid composition of such membrane sub-domains. In particular, inositol phospholipids are a minor class of phospholipids that play pivotal roles in the control of Ca2+-dependent signaling pathways. In this review, we will highlight some of the recent advances in this field as well as their impact in defining future research directions.
Collapse
Affiliation(s)
- Tamas Balla
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Gergo Gulyas
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Yeun Ju Kim
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| | - Joshua Pemberton
- Section on Molecular Signal Transduction, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892
| |
Collapse
|
24
|
Endoplasmic reticulum-plasma membrane contacts: Principals of phosphoinositide and calcium signaling. Curr Opin Cell Biol 2020; 63:125-134. [PMID: 32088611 DOI: 10.1016/j.ceb.2020.01.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 01/18/2020] [Accepted: 01/20/2020] [Indexed: 12/29/2022]
Abstract
The endoplasmic reticulum (ER) forms an extensive network of membrane contact sites with intra-cellular organelles and the plasma membrane (PM). Interorganelle contacts have vital roles in membrane lipid and ion dynamics. In particular, ER-PM contacts are integral to numerous inter-cellular and intra-cellular signaling pathways including phosphoinositide lipid and calcium signaling, mechanotransduction, metabolic regulation, and cell stress responses. Accordingly, ER-PM contacts serve important signaling functions in excitable cells including neurons and muscle and endocrine cells. This review highlights recent advances in our understanding of the vital roles for ER-PM contacts in phosphoinositide and calcium signaling and how signaling pathways in turn regulate proteins that form and function at ER-PM contacts.
Collapse
|
25
|
da Silva DC, Valentão P, Andrade PB, Pereira DM. Endoplasmic reticulum stress signaling in cancer and neurodegenerative disorders: Tools and strategies to understand its complexity. Pharmacol Res 2020; 155:104702. [PMID: 32068119 DOI: 10.1016/j.phrs.2020.104702] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 02/10/2020] [Accepted: 02/13/2020] [Indexed: 12/12/2022]
Abstract
The endoplasmic reticulum (ER) comprises a network of tubules and vesicles that constitutes the largest organelle of the eukaryotic cell. Being the location where most proteins are synthesized and folded, it is crucial for the upkeep of cellular homeostasis. Disturbed ER homeostasis triggers the activation of a conserved molecular machinery, termed the unfolded protein response (UPR), that comprises three major signaling branches, initiated by the protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring enzyme 1 (IRE1) and the activating transcription factor 6 (ATF6). Given the impact of this intricate signaling network upon an extensive list of cellular processes, including protein turnover and autophagy, ER stress is involved in the onset and progression of multiple diseases, including cancer and neurodegenerative disorders. There is, for this reason, an increasing number of publications focused on characterizing and/or modulating ER stress, which have resulted in a wide array of techniques employed to study ER-related molecular events. This review aims to sum up the essentials on the current knowledge of the molecular biology of endoplasmic reticulum stress, while highlighting the available tools used in studies of this nature.
Collapse
Affiliation(s)
- Daniela Correia da Silva
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-213, Porto, Portugal
| | - Patrícia Valentão
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-213, Porto, Portugal
| | - Paula B Andrade
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-213, Porto, Portugal
| | - David M Pereira
- REQUIMTE/LAQV, Laboratório de Farmacognosia, Departamento de Química, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira, 228, 4050-213, Porto, Portugal.
| |
Collapse
|