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Borrelli E, Bandello F, Boon CJF, Carelli V, Lenaers G, Reibaldi M, Sadda SR, Sadun AA, Sarraf D, Yu-Wai-Man P, Barboni P. Mitochondrial retinopathies and optic neuropathies: The impact of retinal imaging on modern understanding of pathogenesis, diagnosis, and management. Prog Retin Eye Res 2024; 101:101264. [PMID: 38703886 DOI: 10.1016/j.preteyeres.2024.101264] [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: 01/11/2024] [Revised: 03/18/2024] [Accepted: 04/26/2024] [Indexed: 05/06/2024]
Abstract
Advancements in ocular imaging have significantly broadened our comprehension of mitochondrial retinopathies and optic neuropathies by examining the structural and pathological aspects of the retina and optic nerve in these conditions. This article aims to review the prominent imaging characteristics associated with mitochondrial retinopathies and optic neuropathies, aiming to deepen our insight into their pathogenesis and clinical features. Preceding this exploration, the article provides a detailed overview of the crucial genetic and clinical features, which is essential for the proper interpretation of in vivo imaging. More importantly, we will provide a critical analysis on how these imaging modalities could serve as biomarkers for characterization and monitoring, as well as in guiding treatment decisions. However, these imaging methods have limitations, which will be discussed along with potential strategies to mitigate them. Lastly, the article will emphasize the potential advantages and future integration of imaging techniques in evaluating patients with mitochondrial eye disorders, considering the prospects of emerging gene therapies.
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Affiliation(s)
- Enrico Borrelli
- Department of Surgical Sciences, University of Turin, Turin, Italy; Department of Ophthalmology, "City of Health and Science" Hospital, Turin, Italy.
| | - Francesco Bandello
- Vita-Salute San Raffaele University, Milan, Italy; IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Camiel J F Boon
- Department of Ophthalmology, Amsterdam University Medical Centers, Amsterdam, the Netherlands; Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | - Valerio Carelli
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy; IRCCS Istituto delle Scienze Neurologiche di Bologna, Programma di Neurogenetica, Bologna, Italy
| | - Guy Lenaers
- Equipe MitoLab, Unité MitoVasc, INSERM U1083, Université d'Angers, 49933, Angers, France; Service de Neurologie, CHU d'Angers, 49100, Angers, France
| | - Michele Reibaldi
- Department of Surgical Sciences, University of Turin, Turin, Italy; Department of Ophthalmology, "City of Health and Science" Hospital, Turin, Italy
| | - Srinivas R Sadda
- Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Doheny Eye Institute, Los Angeles, CA, USA
| | - Alfredo A Sadun
- Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Doheny Eye Institute, Los Angeles, CA, USA
| | - David Sarraf
- Department of Ophthalmology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA; Retinal Disorders and Ophthalmic Genetics Division, Stein Eye Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Patrick Yu-Wai-Man
- John van Geest Centre for Brain Repair and MRC Mitochondrial Biology Unit, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK; Cambridge Eye Unit, Addenbrooke's Hospital, Cambridge University Hospitals, Cambridge, UK; Moorfields Eye Hospital NHS Foundation Trust, London, UK; Institute of Ophthalmology, University College London, London, UK
| | - Piero Barboni
- IRCCS San Raffaele Scientific Institute, Milan, Italy; Studio Oculistico d'Azeglio, Bologna, Italy.
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2
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Gorny H, Mularoni A, Delcros JG, Freton C, Preto J, Krimm I. Combining nano-differential scanning fluorimetry and microscale thermophoresis to investigate VDAC1 interaction with small molecules. J Enzyme Inhib Med Chem 2023; 38:2121821. [PMID: 36650907 PMCID: PMC9858421 DOI: 10.1080/14756366.2022.2121821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
The mitochondrial voltage-dependent anion channel 1 (VDAC1) plays a central role in metabolism and apoptosis, which makes it a promising therapeutic target. Nevertheless, molecular mechanisms governing VDAC1 functioning remain unclear. Small-molecule ligands specifically interacting with the channel provide an attractive way of exploring its structure-function relationships and can possibly be used as founding stones for future drug-candidates. While around 30 VDAC1 ligands have been identified over the years, various techniques have been used by research teams, making a fair and direct comparison between compounds impossible. To tackle this issue, we performed ligand-binding assays on a representative set of seventeen known VDAC1 ligands using nano-differential scanning fluorimetry and microscale thermophoresis. While all the compounds have been confirmed as VDAC1 ligands by at least one method, combining both technologies lead to the selection of four molecules (cannabidiol, curcumin, DIDS and VBIT4) as chemical starting points for future design of VDAC1 selective ligands.
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Affiliation(s)
- Hubert Gorny
- Centre de Recherche en Cancérologie de Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Lyon, France
| | - Angélique Mularoni
- Centre de Recherche en Cancérologie de Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Lyon, France
| | - Jean-Guy Delcros
- Centre de Recherche en Cancérologie de Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Lyon, France
| | - Céline Freton
- Molecular Microbiology and Structural Biochemistry, UMR 5086, Université de Lyon, CNRS, Lyon, France
| | - Jordane Preto
- Centre de Recherche en Cancérologie de Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Lyon, France,CONTACT Jordane Preto
| | - Isabelle Krimm
- Centre de Recherche en Cancérologie de Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Lyon, France,Isabelle Krimm Centre de Recherche en Cancérologie de Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Lyon, France
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3
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Nestorovich EM, Bezrukov SM. Beta-Barrel Channel Response to High Electric Fields: Functional Gating or Reversible Denaturation? Int J Mol Sci 2023; 24:16655. [PMID: 38068977 PMCID: PMC10706840 DOI: 10.3390/ijms242316655] [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: 09/30/2023] [Revised: 11/16/2023] [Accepted: 11/21/2023] [Indexed: 12/18/2023] Open
Abstract
Ion channels exhibit gating behavior, fluctuating between open and closed states, with the transmembrane voltage serving as one of the essential regulators of this process. Voltage gating is a fundamental functional aspect underlying the regulation of ion-selective, mostly α-helical, channels primarily found in excitable cell membranes. In contrast, there exists another group of larger, and less selective, β-barrel channels of a different origin, which are not directly associated with cell excitability. Remarkably, these channels can also undergo closing, or "gating", induced by sufficiently strong electric fields. Once the field is removed, the channels reopen, preserving a memory of the gating process. In this study, we explored the hypothesis that the voltage-induced closure of the β-barrel channels can be seen as a form of reversible protein denaturation by the high electric fields applied in model membranes experiments-typically exceeding twenty million volts per meter-rather than a manifestation of functional gating. Here, we focused on the bacterial outer membrane channel OmpF reconstituted into planar lipid bilayers and analyzed various characteristics of the closing-opening process that support this idea. Specifically, we considered the nearly symmetric response to voltages of both polarities, the presence of multiple closed states, the stabilization of the open conformation in channel clusters, the long-term gating memory, and the Hofmeister effects in closing kinetics. Furthermore, we contemplate the evolutionary aspect of the phenomenon, proposing that the field-induced denaturation of membrane proteins might have served as a starting point for their development into amazing molecular machines such as voltage-gated channels of nerve and muscle cells.
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Affiliation(s)
- Ekaterina M. Nestorovich
- Department of Biology, The Catholic University of America, Washington, DC 20064, USA
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Sergey M. Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA;
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4
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Di Mambro T, Pellielo G, Agyapong ED, Carinci M, Chianese D, Giorgi C, Morciano G, Patergnani S, Pinton P, Rimessi A. The Tricky Connection between Extracellular Vesicles and Mitochondria in Inflammatory-Related Diseases. Int J Mol Sci 2023; 24:8181. [PMID: 37175888 PMCID: PMC10179665 DOI: 10.3390/ijms24098181] [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: 03/28/2023] [Revised: 04/21/2023] [Accepted: 05/01/2023] [Indexed: 05/15/2023] Open
Abstract
Mitochondria are organelles present in almost all eukaryotic cells, where they represent the main site of energy production. Mitochondria are involved in several important cell processes, such as calcium homeostasis, OXPHOS, autophagy, and apoptosis. Moreover, they play a pivotal role also in inflammation through the inter-organelle and inter-cellular communications, mediated by the release of mitochondrial damage-associated molecular patterns (mtDAMPs). It is currently well-documented that in addition to traditional endocrine and paracrine communication, the cells converse via extracellular vesicles (EVs). These small membrane-bound particles are released from cells in the extracellular milieu under physio-pathological conditions. Importantly, EVs have gained much attention for their crucial role in inter-cellular communication, translating inflammatory signals into recipient cells. EVs cargo includes plasma membrane and endosomal proteins, but EVs also contain material from other cellular compartments, including mitochondria. Studies have shown that EVs may transport mitochondrial portions, proteins, and/or mtDAMPs to modulate the metabolic and inflammatory responses of recipient cells. Overall, the relationship between EVs and mitochondria in inflammation is an active area of research, although further studies are needed to fully understand the mechanisms involved and how they may be targeted for therapeutic purposes. Here, we have reported and discussed the latest studies focused on this fascinating and recent area of research, discussing of tricky connection between mitochondria and EVs in inflammatory-related diseases.
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Affiliation(s)
- Tommaso Di Mambro
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy; (T.D.M.); (G.P.); (E.D.A.); (M.C.); (D.C.); (C.G.); (G.M.); (S.P.); (P.P.)
| | - Giulia Pellielo
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy; (T.D.M.); (G.P.); (E.D.A.); (M.C.); (D.C.); (C.G.); (G.M.); (S.P.); (P.P.)
| | - Esther Densu Agyapong
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy; (T.D.M.); (G.P.); (E.D.A.); (M.C.); (D.C.); (C.G.); (G.M.); (S.P.); (P.P.)
| | - Marianna Carinci
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy; (T.D.M.); (G.P.); (E.D.A.); (M.C.); (D.C.); (C.G.); (G.M.); (S.P.); (P.P.)
| | - Diego Chianese
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy; (T.D.M.); (G.P.); (E.D.A.); (M.C.); (D.C.); (C.G.); (G.M.); (S.P.); (P.P.)
| | - Carlotta Giorgi
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy; (T.D.M.); (G.P.); (E.D.A.); (M.C.); (D.C.); (C.G.); (G.M.); (S.P.); (P.P.)
| | - Giampaolo Morciano
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy; (T.D.M.); (G.P.); (E.D.A.); (M.C.); (D.C.); (C.G.); (G.M.); (S.P.); (P.P.)
| | - Simone Patergnani
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy; (T.D.M.); (G.P.); (E.D.A.); (M.C.); (D.C.); (C.G.); (G.M.); (S.P.); (P.P.)
| | - Paolo Pinton
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy; (T.D.M.); (G.P.); (E.D.A.); (M.C.); (D.C.); (C.G.); (G.M.); (S.P.); (P.P.)
- Center of Research for Innovative Therapies in Cystic Fibrosis, University of Ferrara, 44121 Ferrara, Italy
| | - Alessandro Rimessi
- Department of Medical Sciences, Section of Experimental Medicine, Laboratory for Technologies of Advanced Therapies, University of Ferrara, 44121 Ferrara, Italy; (T.D.M.); (G.P.); (E.D.A.); (M.C.); (D.C.); (C.G.); (G.M.); (S.P.); (P.P.)
- Center of Research for Innovative Therapies in Cystic Fibrosis, University of Ferrara, 44121 Ferrara, Italy
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5
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Koren DT, Shrivastava R, Ghosh S. Ca 2+/Calmodulin-Dependent Protein Kinase II Disrupts the Voltage Dependency of the Voltage-Dependent Anion Channel on the Lipid Bilayer Membrane. J Phys Chem B 2023; 127:3372-3381. [PMID: 37040575 DOI: 10.1021/acs.jpcb.3c00142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Ca2+/calmodulin-dependent protein kinase II (CaMKII) is a key enzyme that plays a significant role in intracellular signaling and the modulation of mitochondrial membrane properties. It is known that the voltage-dependent anion channel (VDAC) is one of the most abundant outer mitochondrial membrane (OMM) proteins acting as a significant passageway and regulatory site for various enzymes, proteins, ions, and metabolites. Considering this, we hypothesize that VDAC could be one of the targets for CaMKII enzymatic activity. Our in vitro experiments indicate that VDAC can be phosphorylated by the CaMKII enzyme. Moreover, the bilayer electrophysiology experimental data indicate that CaMKII significantly reduces VDAC's single-channel conductivity; its open probability remains high at all the applied potentials between +60 and -60 mV, and the voltage dependency was lost, which suggests that CaMKII disrupted the VDAC's single-channel activities. Hence, we can infer that VDAC interacts with CaMKII and thus acts as a vital target for its activity. Furthermore, our findings suggest that CaMKII could play a significant role during the transport of ions and metabolites across the outer mitochondrial membrane (OMM) through VDAC and thus regulate apoptotic events.
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Affiliation(s)
| | - Rajan Shrivastava
- Department of Biophysics, University of Delhi South Campus, New Delhi 110021, India
| | - Subhendu Ghosh
- Department of Biophysics, University of Delhi South Campus, New Delhi 110021, India
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6
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Mannella C. In Silico Exploration of Alternative Conformational States of VDAC. Molecules 2023; 28:molecules28083309. [PMID: 37110543 PMCID: PMC10144127 DOI: 10.3390/molecules28083309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 04/03/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
VDAC (Voltage-Dependent Anion-selective Channel) is the primary metabolite pore in the mitochondrial outer membrane (OM). Atomic structures of VDAC, consistent with its physiological "open" state, are β-barrels formed by 19 transmembrane (TM) β-strands and an N-terminal segment (NTERM) that folds inside the pore lumen. However, structures are lacking for VDAC's partially "closed" states. To provide clues about possible VDAC conformers, we used the RoseTTAFold neural network to predict structures for human and fungal VDAC sequences modified to mimic removal from the pore wall or lumen of "cryptic" domains, i.e., segments buried in atomic models yet accessible to antibodies in OM-bound VDAC. Predicted in vacuo structures for full-length VDAC sequences are 19-strand β-barrels similar to atomic models, but with weaker H-bonding between TM strands and reduced interactions between NTERM and the pore wall. Excision of combinations of "cryptic" subregions yields β-barrels with smaller diameters, wide gaps between N- and C-terminal β-strands, and in some cases disruption of the β-sheet (associated with strained backbone H-bond registration). Tandem repeats of modified VDAC sequences also were explored, as was domain swapping in monomer constructs. Implications of the results for possible alternative conformational states of VDAC are discussed.
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Affiliation(s)
- Carmen Mannella
- Department of Physiology and Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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7
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Wang X, Zhou Y, Wang D, Wang Y, Zhou Z, Ma X, Liu X, Dong Y. Cisplatin-induced ototoxicity: From signaling network to therapeutic targets. Biomed Pharmacother 2023; 157:114045. [PMID: 36455457 DOI: 10.1016/j.biopha.2022.114045] [Citation(s) in RCA: 39] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/15/2022] [Accepted: 11/25/2022] [Indexed: 11/29/2022] Open
Abstract
Administration of cisplatin, a common chemotherapeutic drug, has an inevitable side effect of sensorineural hearing loss. The main etiologies are stria vascularis injury, spiral ganglion degeneration, and hair cell death. Over several decades, the research scope of cisplatin-induced ototoxicity has expanded with the discovery of the molecular mechanism mediating inner ear cell death, highlighting the roles of reactive oxygen species and transport channels for cisplatin uptake into inner ear cells. Upon entering hair cells, cisplatin disrupts organelle metabolism, induces oxidative stress, and targets DNA to cause intracellular damage. Recent studies have also reported the role of inflammation in cisplatin-induced ototoxicity. In this article, we preform a narrative review of the latest reported molecular mechanisms of cisplatin-induced ototoxicity, from extracellular to intracellular. We build up a signaling network starting with cisplatin entering into the inner ear through the blood labyrinth barrier, disrupting cochlear endolymph homeostasis, and activating inflammatory responses of the outer hair cells. After entering the hair cells, cisplatin causes hair cell death via DNA damage, redox system imbalance, and mitochondrial and endoplasmic reticulum dysfunction, culminating in programmed cell death including apoptosis, necroptosis, autophagic death, pyroptosis, and ferroptosis. Based on the mentioned mechanisms, prominent therapeutic targets, such as channel-blocking drugs of cisplatin transporter, construction of cisplatin structural analogues, anti-inflammatory drugs, antioxidants, cell death inhibitors, and others, were collated. Considering the recent research efforts, we have analyzed the feasibility of the aforementioned therapeutic strategies and proposed our otoprotective approaches to overcome cisplatin-induced ototoxicity.
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Affiliation(s)
- Xilu Wang
- Department of Otolaryngology Head and Neck Surgery, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yingying Zhou
- Department of Obstetrics & gynecology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Dali Wang
- Department of Otolaryngology Head and Neck Surgery, Shengjing Hospital of China Medical University, Shenyang, China
| | - Yi Wang
- Department of Otolaryngology Head and Neck Surgery, Shengjing Hospital of China Medical University, Shenyang, China
| | - Zhaoyu Zhou
- Department of Otolaryngology Head and Neck Surgery, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xiulan Ma
- Department of Otolaryngology Head and Neck Surgery, Shengjing Hospital of China Medical University, Shenyang, China
| | - Xiaofang Liu
- Department of Surgical Oncology, the First Affiliated Hospital of China Medical University, Shenyang, China.
| | - Yaodong Dong
- Department of Otolaryngology Head and Neck Surgery, Shengjing Hospital of China Medical University, Shenyang, China.
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8
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Rister AB, Gudermann T, Schredelseker J. E as in Enigma: The Mysterious Role of the Voltage-Dependent Anion Channel Glutamate E73. Int J Mol Sci 2022; 24:ijms24010269. [PMID: 36613710 PMCID: PMC9820230 DOI: 10.3390/ijms24010269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/07/2022] [Accepted: 12/12/2022] [Indexed: 12/28/2022] Open
Abstract
The voltage-dependent anion channel (VDAC) is the main passageway for ions and metabolites over the outer mitochondrial membrane. It was associated with many physiological processes, including apoptosis and modulation of intracellular Ca2+ signaling. The protein is formed by a barrel of 19 beta-sheets with an N-terminal helix lining the inner pore. Despite its large diameter, the channel can change its selectivity for ions and metabolites based on its open state to regulate transport into and out of mitochondria. VDAC was shown to be regulated by a variety of cellular factors and molecular partners including proteins, lipids and ions. Although the physiological importance of many of these modulatory effects are well described, the binding sites for molecular partners are still largely unknown. The highly symmetrical and sleek structure of the channel makes predictions of functional moieties difficult. However, one residue repeatedly sticks out when reviewing VDAC literature. A glutamate at position 73 (E73) located on the outside of the channel facing the hydrophobic membrane environment was repeatedly proposed to be involved in channel regulation on multiple levels. Here, we review the distinct hypothesized roles of E73 and summarize the open questions around this mysterious residue.
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Affiliation(s)
- Alexander Bernhard Rister
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, 80336 Munich, Germany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, 80336 Munich, Germany
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Partner Site Munich Heart Alliance, Munich, Germany
| | - Johann Schredelseker
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, 80336 Munich, Germany
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Partner Site Munich Heart Alliance, Munich, Germany
- Correspondence: ; Tel.: +49-(0)89-2180-73831
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9
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Ngo VA, Queralt-Martín M, Khan F, Bergdoll L, Abramson J, Bezrukov SM, Rostovtseva TK, Hoogerheide DP, Noskov SY. The Single Residue K12 Governs the Exceptional Voltage Sensitivity of Mitochondrial Voltage-Dependent Anion Channel Gating. J Am Chem Soc 2022; 144:14564-14577. [PMID: 35925797 DOI: 10.1021/jacs.2c03316] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The voltage-dependent anion channel (VDAC) is a β-barrel channel of the mitochondrial outer membrane (MOM) that passively transports ions, metabolites, polypeptides, and single-stranded DNA. VDAC responds to a transmembrane potential by "gating," i.e. transitioning to one of a variety of low-conducting states of unknown structure. The gated state results in nearly complete suppression of multivalent mitochondrial metabolite (such as ATP and ADP) transport, while enhancing calcium transport. Voltage gating is a universal property of β-barrel channels, but VDAC gating is anomalously sensitive to transmembrane potential. Here, we show that a single residue in the pore interior, K12, is responsible for most of VDAC's voltage sensitivity. Using the analysis of over 40 μs of atomistic molecular dynamics (MD) simulations, we explore correlations between motions of charged residues inside the VDAC pore and geometric deformations of the β-barrel. Residue K12 is bistable; its motions between two widely separated positions along the pore axis enhance the fluctuations of the β-barrel and augment the likelihood of gating. Single channel electrophysiology of various K12 mutants reveals a dramatic reduction of the voltage-induced gating transitions. The crystal structure of the K12E mutant at a resolution of 2.6 Å indicates a similar architecture of the K12E mutant to the wild type; however, 60 μs of atomistic MD simulations using the K12E mutant show restricted motion of residue 12, due to enhanced connectivity with neighboring residues, and diminished amplitude of barrel motions. We conclude that β-barrel fluctuations, governed particularly by residue K12, drive VDAC gating transitions.
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Affiliation(s)
- Van A Ngo
- Center for Molecular Simulations, Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada.,Advanced Computing for Life Sciences and Engineering, Computing and Computational Sciences, National Center for Computational Sciences, Oak Ridge National Lab, Oak Ridge, Tennessee 37830, United States
| | - María Queralt-Martín
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, United States.,Laboratory of Molecular Biophysics, Department of Physics, Universitat Jaume I, 12071 Castellón, Spain
| | - Farha Khan
- Department of Physiology, University of California, Los Angeles, California 90095, United States
| | - Lucie Bergdoll
- LISM UMR 7255, CNRS and Aix-Marseille University, Marseille cedex 20, 13402, France
| | - Jeff Abramson
- Department of Physiology, University of California, Los Angeles, California 90095, United States
| | - Sergey M Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - Tatiana K Rostovtseva
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, United States
| | - David P Hoogerheide
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | - Sergei Yu Noskov
- Center for Molecular Simulations, Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada
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10
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Heslop KA, Burger P, Kappler C, Solanki AK, Gooz M, Peterson YK, Mills C, Benton T, Duncan SA, Woster PM, Maldonado EN. Small molecules targeting the NADH-binding pocket of VDAC modulate mitochondrial metabolism in hepatocarcinoma cells. Biomed Pharmacother 2022; 150:112928. [PMID: 35447542 PMCID: PMC9400819 DOI: 10.1016/j.biopha.2022.112928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/25/2022] [Accepted: 04/05/2022] [Indexed: 11/18/2022] Open
Abstract
Voltage dependent anion channels (VDAC) control the flux of most anionic respiratory substrates, ATP, ADP, and small cations, crossing the outer mitochondrial membrane. VDAC closure contributes to the partial suppression of mitochondrial metabolism that favors the Warburg phenotype of cancer cells. Recently, it has been shown that NADH binds to a specific pocket in the inner surface of VDAC1, also conserved in VDAC2 and 3, closing the channel. We hypothesized that binding of small molecules to the NADH pocket, maintain VDAC in an open configuration by preventing closure induced by NADH and possible other endogenous regulators. We screened in silico, the South Carolina Compound Collection SC3 (~ 100,000 proprietary molecules), using shape-based queries of the NADH binding region of VDAC. After molecular docking of selected compounds, we physically screened candidates using mitochondrial membrane potential (ΔΨm), as an overall readout of mitochondrial metabolism. We identified SC18, as the most potent compound. SC18 bound to VDAC1, as assessed by a thermal shift assay. Short-term treatment with SC18 decreased ΔΨm in SNU-449 and HepG2 human hepatocarcinoma cells. Mitochondrial depolarization was similar in wild type, VDAC1/2, 1/3, and 2/3 double KO HepG2 cells indicating that the effect of SC18 was not VDAC isoform-dependent. In addition, SC18 decreased mitochondrial NADH and cellular ATP production; and increased basal respiration. Long-term exposure to SC18, decreased cell proliferation as determined by wound-healing and cell viability assays. In summary, SC18 is a novel VDAC-targeting small molecule that induces mitochondrial dysfunction and inhibits cell proliferation.
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Affiliation(s)
- Kareem A Heslop
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Pieter Burger
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Christiana Kappler
- Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Ashish K Solanki
- Nephrology Division, Medical University of South Carolina, Charleston, SC, USA
| | - Monika Gooz
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Yuri K Peterson
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Catherine Mills
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Thomas Benton
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Stephen A Duncan
- Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC, USA
| | - Patrick M Woster
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Eduardo N Maldonado
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA.
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11
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Chemotherapy Resistance: Role of Mitochondrial and Autophagic Components. Cancers (Basel) 2022; 14:cancers14061462. [PMID: 35326612 PMCID: PMC8945922 DOI: 10.3390/cancers14061462] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 03/10/2022] [Accepted: 03/10/2022] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Chemotherapy resistance is a common occurrence during cancer treatment that cancer researchers are attempting to understand and overcome. Mitochondria are a crucial intracellular signaling core that are becoming important determinants of numerous aspects of cancer genesis and progression, such as metabolic reprogramming, metastatic capability, and chemotherapeutic resistance. Mitophagy, or selective autophagy of mitochondria, can influence both the efficacy of tumor chemotherapy and the degree of drug resistance. Regardless of the fact that mitochondria are well-known for coordinating ATP synthesis from cellular respiration in cellular bioenergetics, little is known its mitophagy regulation in chemoresistance. Recent advancements in mitochondrial research, mitophagy regulatory mechanisms, and their implications for our understanding of chemotherapy resistance are discussed in this review. Abstract Cancer chemotherapy resistance is one of the most critical obstacles in cancer therapy. One of the well-known mechanisms of chemotherapy resistance is the change in the mitochondrial death pathways which occur when cells are under stressful situations, such as chemotherapy. Mitophagy, or mitochondrial selective autophagy, is critical for cell quality control because it can efficiently break down, remove, and recycle defective or damaged mitochondria. As cancer cells use mitophagy to rapidly sweep away damaged mitochondria in order to mediate their own drug resistance, it influences the efficacy of tumor chemotherapy as well as the degree of drug resistance. Yet despite the importance of mitochondria and mitophagy in chemotherapy resistance, little is known about the precise mechanisms involved. As a consequence, identifying potential therapeutic targets by analyzing the signal pathways that govern mitophagy has become a vital research goal. In this paper, we review recent advances in mitochondrial research, mitophagy control mechanisms, and their implications for our understanding of chemotherapy resistance.
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12
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Najbauer EE, Tekwani Movellan K, Giller K, Benz R, Becker S, Griesinger C, Andreas LB. Structure and Gating Behavior of the Human Integral Membrane Protein VDAC1 in a Lipid Bilayer. J Am Chem Soc 2022; 144:2953-2967. [PMID: 35164499 PMCID: PMC8874904 DOI: 10.1021/jacs.1c09848] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
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The voltage-dependent
anion channel (VDAC), the most abundant protein
in the outer mitochondrial membrane, is responsible for the transport
of all ions and metabolites into and out of mitochondria. Larger than
any of the β-barrel structures determined to date by magic-angle
spinning (MAS) NMR, but smaller than the size limit of cryo-electron
microscopy (cryo-EM), VDAC1’s 31 kDa size has long been a bottleneck
in determining its structure in a near-native lipid bilayer environment.
Using a single two-dimensional (2D) crystalline sample of human VDAC1
in lipids, we applied proton-detected fast magic-angle spinning NMR
spectroscopy to determine the arrangement of β strands. Combining
these data with long-range restraints from a spin-labeled sample,
chemical shift-based secondary structure prediction, and previous
MAS NMR and atomic force microscopy (AFM) data, we determined the
channel’s structure at a 2.2 Å root-mean-square deviation
(RMSD). The structure, a 19-stranded β-barrel, with an N-terminal
α-helix in the pore is in agreement with previous data in detergent,
which was questioned due to the potential for the detergent to perturb
the protein’s functional structure. Using a quintuple mutant
implementing the channel’s closed state, we found that dynamics
are a key element in the protein’s gating behavior, as channel
closure leads to the destabilization of not only the C-terminal barrel
residues but also the α2 helix. We showed that cholesterol,
previously shown to reduce the frequency of channel closure, stabilizes
the barrel relative to the N-terminal helix. Furthermore, we observed
channel closure through steric blockage by a drug shown to selectively
bind to the channel, the Bcl2-antisense oligonucleotide G3139.
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Affiliation(s)
- Eszter E Najbauer
- Department of NMR-Based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077 Göttingen, Germany
| | - Kumar Tekwani Movellan
- Department of NMR-Based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077 Göttingen, Germany
| | - Karin Giller
- Department of NMR-Based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077 Göttingen, Germany
| | - Roland Benz
- Life Sciences and Chemistry, Jacobs University of Bremen, Campus Ring 1, 28759 Bremen, Germany
| | - Stefan Becker
- Department of NMR-Based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077 Göttingen, Germany
| | - Christian Griesinger
- Department of NMR-Based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077 Göttingen, Germany
| | - Loren B Andreas
- Department of NMR-Based Structural Biology, Max Planck Institute for Multidisciplinary Sciences, Am Faßberg 11, 37077 Göttingen, Germany
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13
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Preto J, Gorny H, Krimm I. A Deep Dive into VDAC1 Conformational Diversity Using All-Atom Simulations Provides New Insights into the Structural Origin of the Closed States. Int J Mol Sci 2022; 23:ijms23031175. [PMID: 35163095 PMCID: PMC8834982 DOI: 10.3390/ijms23031175] [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] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 01/13/2022] [Accepted: 01/19/2022] [Indexed: 01/14/2023] Open
Abstract
The voltage-dependent anion channel 1 (VDAC1) is a crucial mitochondrial transporter that controls the flow of ions and respiratory metabolites entering or exiting mitochondria. As a voltage-gated channel, VDAC1 can switch between a high-conducting “open” state and a low-conducting “closed” state emerging at high transmembrane (TM) potentials. Although cell homeostasis depends on channel gating to regulate the transport of ions and metabolites, structural hallmarks characterizing the closed states remain unknown. Here, we performed microsecond accelerated molecular dynamics to highlight a vast region of VDAC1 conformational landscape accessible at typical voltages known to promote closure. Conformers exhibiting durable subconducting properties inherent to closed states were identified. In all cases, the low conductance was due to the particular positioning of an unfolded part of the N-terminus, which obstructed the channel pore. While the N-terminal tail was found to be sensitive to voltage orientation, our models suggest that stable low-conducting states of VDAC1 predominantly take place from disordered events and do not result from the displacement of a voltage sensor or a significant change in the pore. In addition, our results were consistent with conductance jumps observed experimentally and corroborated a recent study describing entropy as a key factor for VDAC gating.
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14
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Aljamal J. Effect of Lysine and Histidine Residues Modification on the Voltage Gating of the Mitochondrial Porin. JOURNAL OF BIOCHEMICAL TECHNOLOGY 2022. [DOI: 10.51847/dvlzksdsn8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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15
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VDAC2 and the BCL-2 family of proteins. Biochem Soc Trans 2021; 49:2787-2795. [PMID: 34913469 PMCID: PMC8786305 DOI: 10.1042/bst20210753] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/21/2021] [Accepted: 11/26/2021] [Indexed: 12/26/2022]
Abstract
The BCL-2 protein family govern whether a cell dies or survives by controlling mitochondrial apoptosis. As dysregulation of mitochondrial apoptosis is a common feature of cancer cells, targeting protein–protein interactions within the BCL-2 protein family is a key strategy to seize control of apoptosis and provide favourable outcomes for cancer patients. Non-BCL-2 family proteins are emerging as novel regulators of apoptosis and are potential drug targets. Voltage dependent anion channel 2 (VDAC2) can regulate apoptosis. However, it is unclear how this occurs at the molecular level, with conflicting evidence in the literature for its role in regulating the BCL-2 effector proteins, BAK and BAX. Notably, VDAC2 is required for efficient BAX-mediated apoptosis, but conversely inhibits BAK-mediated apoptosis. This review focuses on the role of VDAC2 in apoptosis, discussing the current knowledge of the interaction between VDAC2 and BCL-2 family proteins and the recent development of an apoptosis inhibitor that targets the VDAC2–BAK interaction.
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16
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Gong J, Zhu M, Zhan M, Xi C, Xu Z, Shui Y, Shen H. PcVDAC promotes WSSV infection by regulating the apoptotic activity of haemocytes in Procambarus clarkii. Comp Biochem Physiol B Biochem Mol Biol 2021; 259:110697. [PMID: 34798242 DOI: 10.1016/j.cbpb.2021.110697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/07/2021] [Accepted: 11/12/2021] [Indexed: 11/15/2022]
Abstract
Apoptosis is programmed cell death that is strictly regulated by a series of related genes and is of great importance in resisting pathogen invasion and maintaining cell environment homeostasis. Among apoptotic proteins, the voltage-dependent anion channel protein (VDAC) plays a key role in the mitochondrial apoptosis pathway because of its close connection with changes in mitochondrial membrane potential. However, the role of VDAC in apoptosis and immune regulation in Procambarus clarkii is poorly understood. In this study, the VDAC gene in P. clarkii (PcVDAC) was cloned by rapid amplification of cDNA ends (RACE) technology. The gene was found to have a total length of 2277 bp, including a 194-bp 5'-UTR, 1234-bp 3'-UTR and 849-bp open reading frame (ORF), and to encode 282 amino acids. PcVDAC was expressed in all tissues tested, and its expression was upregulated after white spot syndrome virus (WSSV) infection (P < 0.05). The RNA interference (RNAi) method was used to explore the role of PcVDAC in WSSV infection. The results showed that the number of WSSV copies in haemocytes was significantly reduced after RNAi (P < 0.05), and the survival rate was significantly increased. In addition, after RNAi, the apoptosis rate was significantly increased (P < 0.05), the mitochondrial membrane potential was reduced (P < 0.01), and the expression of caspase-3 and other genes was upregulated (P < 0.05). These results indicate that PcVDAC promotes the replication of WSSV in P. clarkii by inhibiting haemocytes apoptosis. Therefore, the results presented in this paper provide new insights into the immune response of P. clarkii infected with WSSV.
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Affiliation(s)
- Jie Gong
- Wuxi Fisheries College, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Mengru Zhu
- Wuxi Fisheries College, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Ming Zhan
- Wuxi Fisheries College, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Changjun Xi
- Wuxi Fisheries College, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China
| | - Zenghong Xu
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
| | - Yan Shui
- Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
| | - Huaishun Shen
- Wuxi Fisheries College, Nanjing Agricultural University, Nanjing 210095, China; Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081, China.
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17
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Heslop KA, Milesi V, Maldonado EN. VDAC Modulation of Cancer Metabolism: Advances and Therapeutic Challenges. Front Physiol 2021; 12:742839. [PMID: 34658929 PMCID: PMC8511398 DOI: 10.3389/fphys.2021.742839] [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: 07/16/2021] [Accepted: 08/25/2021] [Indexed: 12/16/2022] Open
Abstract
Most anionic metabolites including respiratory substrates, glycolytic adenosine triphosphate (ATP), and small cations that enter mitochondria, and mitochondrial ATP moving to the cytosol, cross the outer mitochondrial membrane (OMM) through voltage dependent anion channels (VDAC). The closed states of VDAC block the passage of anionic metabolites, and increase the flux of small cations, including calcium. Consequently, physiological or pharmacological regulation of VDAC opening, by conditioning the magnitude of both anion and cation fluxes, is a major contributor to mitochondrial metabolism. Tumor cells display a pro-proliferative Warburg phenotype characterized by enhanced aerobic glycolysis in the presence of partial suppression of mitochondrial metabolism. The heterogeneous and flexible metabolic traits of most human tumors render cells able to adapt to the constantly changing energetic and biosynthetic demands by switching between predominantly glycolytic or oxidative phenotypes. Here, we describe the biological consequences of changes in the conformational state of VDAC for cancer metabolism, the mechanisms by which VDAC-openers promote cancer cell death, and the advantages of VDAC opening as a valuable pharmacological target. Particular emphasis is given to the endogenous regulation of VDAC by free tubulin and the effects of VDAC-tubulin antagonists in cancer cells. Because of its function and location, VDAC operates as a switch to turn-off mitochondrial metabolism (closed state) and increase aerobic glycolysis (pro-Warburg), or to turn-on mitochondrial metabolism (open state) and decrease glycolysis (anti-Warburg). A better understanding of the role of VDAC regulation in tumor progression is relevant both for cancer biology and for developing novel cancer chemotherapies.
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Affiliation(s)
- Kareem A Heslop
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States
| | - Veronica Milesi
- Facultad de Ciencias Exactas, Instituto de Estudios Inmunológicos y Fisiopatológicos (IIFP), UNLP, CONICET, CIC PBA, La Plata, Argentina
| | - Eduardo N Maldonado
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States.,Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States
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18
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Molecular mechanism of thiamine pyrophosphate import into mitochondria: a molecular simulation study. J Comput Aided Mol Des 2021; 35:987-1007. [PMID: 34406552 DOI: 10.1007/s10822-021-00414-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 07/26/2021] [Indexed: 10/20/2022]
Abstract
The import of thiamine pyrophosphate (TPP) through both mitochondrial membranes was studied using a total of 3-µs molecular dynamics simulations. Regarding the translocation through the mitochondrial outer membrane, our simulations support the conjecture that TPP uses the voltage-dependent anion channel, the major pore of this membrane, for its passage to the intermembrane space, as its transport presents significant analogies with that used by other metabolites previously studied, in particular with ATP. As far as passing through the mitochondrial inner membrane is concerned, our simulations show that the specific carrier of TPP has a single binding site that becomes accessible, through an alternating access mechanism. The preference of this transporter for TPP can be rationalized mainly by three residues located in the binding site that differ from those identified in the ATP/ADP carrier, the most studied member of the mitochondrial carrier family. The simulated transport mechanism of TPP highlights the essential role, at the energetic level, of the contributions coming from the formation and breakage of two networks of salt bridges, one on the side of the matrix and the other on the side of the intermembrane space, as well as the interactions, mainly of an ionic nature, formed by TPP upon its binding. The energy contribution provided by the cytosolic network establishes a lower barrier than that of the matrix network, which can be explained by the lower interaction energy of TPP on the matrix side or possibly a uniport activity.
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19
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Rostovtseva TK, Bezrukov SM, Hoogerheide DP. Regulation of Mitochondrial Respiration by VDAC Is Enhanced by Membrane-Bound Inhibitors with Disordered Polyanionic C-Terminal Domains. Int J Mol Sci 2021; 22:7358. [PMID: 34298976 PMCID: PMC8306229 DOI: 10.3390/ijms22147358] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 12/18/2022] Open
Abstract
The voltage-dependent anion channel (VDAC) is the primary regulating pathway of water-soluble metabolites and ions across the mitochondrial outer membrane. When reconstituted into lipid membranes, VDAC responds to sufficiently large transmembrane potentials by transitioning to gated states in which ATP/ADP flux is reduced and calcium flux is increased. Two otherwise unrelated cytosolic proteins, tubulin, and α-synuclein (αSyn), dock with VDAC by a novel mechanism in which the transmembrane potential draws their disordered, polyanionic C-terminal domains into and through the VDAC channel, thus physically blocking the pore. For both tubulin and αSyn, the blocked state is observed at much lower transmembrane potentials than VDAC gated states, such that in the presence of these cytosolic docking proteins, VDAC's sensitivity to transmembrane potential is dramatically increased. Remarkably, the features of the VDAC gated states relevant for bioenergetics-reduced metabolite flux and increased calcium flux-are preserved in the blocked state induced by either docking protein. The ability of tubulin and αSyn to modulate mitochondrial potential and ATP production in vivo is now supported by many studies. The common physical origin of the interactions of both tubulin and αSyn with VDAC leads to a general model of a VDAC inhibitor, facilitates predictions of the effect of post-translational modifications of known inhibitors, and points the way toward the development of novel therapeutics targeting VDAC.
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Affiliation(s)
- Tatiana K. Rostovtseva
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA;
| | - Sergey M. Bezrukov
- Program in Physical Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA;
| | - David P. Hoogerheide
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899, USA;
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20
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Queralt-Martín M, Bergdoll L, Teijido O, Munshi N, Jacobs D, Kuszak AJ, Protchenko O, Reina S, Magrì A, De Pinto V, Bezrukov SM, Abramson J, Rostovtseva TK. A lower affinity to cytosolic proteins reveals VDAC3 isoform-specific role in mitochondrial biology. J Gen Physiol 2021; 152:133600. [PMID: 31935282 PMCID: PMC7062508 DOI: 10.1085/jgp.201912501] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 11/20/2019] [Indexed: 01/30/2023] Open
Abstract
Voltage-dependent anion channel (VDAC) is the major pathway for the transport of ions and metabolites across the mitochondrial outer membrane. Among the three known mammalian VDAC isoforms, VDAC3 is the least characterized, but unique functional roles have been proposed in cellular and animal models. Yet, a high-sequence similarity between VDAC1 and VDAC3 is indicative of a similar pore-forming structure. Here, we conclusively show that VDAC3 forms stable, highly conductive voltage-gated channels that, much like VDAC1, are weakly anion selective and facilitate metabolite exchange, but exhibit unique properties when interacting with the cytosolic proteins α-synuclein and tubulin. These two proteins are known to be potent regulators of VDAC1 and induce similar characteristic blockages (on the millisecond time scale) of VDAC3, but with 10- to 100-fold reduced on-rates and altered α-synuclein blocking times, indicative of an isoform-specific function. Through cysteine scanning mutagenesis, we found that VDAC3's cysteine residues regulate its interaction with α-synuclein, demonstrating VDAC3-unique functional properties and further highlighting a general molecular mechanism for VDAC isoform-specific regulation of mitochondrial bioenergetics.
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Affiliation(s)
- María Queralt-Martín
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Lucie Bergdoll
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Oscar Teijido
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Nabill Munshi
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Daniel Jacobs
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Adam J Kuszak
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Olga Protchenko
- Liver Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Simona Reina
- Department of Biological, Geological and Environmental Sciences, University of Catania, Catania, Italy
| | - Andrea Magrì
- Department of Biological, Geological and Environmental Sciences, University of Catania, Catania, Italy
| | - Vito De Pinto
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Sergey M Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
| | - Jeff Abramson
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA
| | - Tatiana K Rostovtseva
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD
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Sabirov RZ, Islam MR, Okada T, Merzlyak PG, Kurbannazarova RS, Tsiferova NA, Okada Y. The ATP-Releasing Maxi-Cl Channel: Its Identity, Molecular Partners and Physiological/Pathophysiological Implications. Life (Basel) 2021; 11:life11060509. [PMID: 34073084 PMCID: PMC8229958 DOI: 10.3390/life11060509] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 05/27/2021] [Indexed: 12/18/2022] Open
Abstract
The Maxi-Cl phenotype accounts for the majority (app. 60%) of reports on the large-conductance maxi-anion channels (MACs) and has been detected in almost every type of cell, including placenta, endothelium, lymphocyte, cardiac myocyte, neuron, and glial cells, and in cells originating from humans to frogs. A unitary conductance of 300-400 pS, linear current-to-voltage relationship, relatively high anion-to-cation selectivity, bell-shaped voltage dependency, and sensitivity to extracellular gadolinium are biophysical and pharmacological hallmarks of the Maxi-Cl channel. Its identification as a complex with SLCO2A1 as a core pore-forming component and two auxiliary regulatory proteins, annexin A2 and S100A10 (p11), explains the activation mechanism as Tyr23 dephosphorylation at ANXA2 in parallel with calcium binding at S100A10. In the resting state, SLCO2A1 functions as a prostaglandin transporter whereas upon activation it turns to an anion channel. As an efficient pathway for chloride, Maxi-Cl is implicated in a number of physiologically and pathophysiologically important processes, such as cell volume regulation, fluid secretion, apoptosis, and charge transfer. Maxi-Cl is permeable for ATP and other small signaling molecules serving as an electrogenic pathway in cell-to-cell signal transduction. Mutations at the SLCO2A1 gene cause inherited bone and gut pathologies and malignancies, signifying the Maxi-Cl channel as a perspective pharmacological target.
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Affiliation(s)
- Ravshan Z. Sabirov
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent 100174, Uzbekistan
- Correspondence: (R.Z.S.); (Y.O.); Tel.: +81-46-858-1501 (Y.O.); Fax: +81-46-858-1542 (Y.O.)
| | - Md. Rafiqul Islam
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Department of Biochemistry and Molecular Biology, Jagannath University, Dhaka 1100, Bangladesh
| | - Toshiaki Okada
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Veneno Technologies Co. Ltd., Tsukuba 305-0031, Japan
| | - Petr G. Merzlyak
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent 100174, Uzbekistan
| | - Ranokhon S. Kurbannazarova
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent 100174, Uzbekistan
| | - Nargiza A. Tsiferova
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Institute of Biophysics and Biochemistry, National University of Uzbekistan, Tashkent 100174, Uzbekistan
| | - Yasunobu Okada
- Division of Cell Signaling, National Institute for Physiological Sciences (NIPS), Okazaki 444-8787, Japan; (M.R.I.); (T.O.); (P.G.M.); (R.S.K.); (N.A.T.)
- Department of Physiology, Kyoto Prefectural University of Medicine, Kyoto 602-8566, Japan
- Department of Physiology, School of Medicine, Aichi Medical University, Nagakute 480-1195, Japan
- Correspondence: (R.Z.S.); (Y.O.); Tel.: +81-46-858-1501 (Y.O.); Fax: +81-46-858-1542 (Y.O.)
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Ruiz-Iglesias A, Mañes S. The Importance of Mitochondrial Pyruvate Carrier in Cancer Cell Metabolism and Tumorigenesis. Cancers (Basel) 2021; 13:cancers13071488. [PMID: 33804985 PMCID: PMC8037430 DOI: 10.3390/cancers13071488] [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: 02/16/2021] [Revised: 03/16/2021] [Accepted: 03/19/2021] [Indexed: 02/06/2023] Open
Abstract
Simple Summary The characteristic metabolic hallmark of cancer cells is the massive catabolism of glucose by glycolysis, even under aerobic conditions—the so-called Warburg effect. Although energetically unfavorable, glycolysis provides “building blocks” to sustain the unlimited growth of malignant cells. Aberrant glycolysis is also responsible for lactate accumulation and acidosis in the tumor milieu, which fosters hypoxia and immunosuppression. One of the mechanisms used by cancer cells to increase glycolytic flow is the negative regulation of the proteins that conform the mitochondrial pyruvate carrier (MPC) complex, which transports pyruvate into the mitochondrial matrix to be metabolized in the tricarboxylic acid (TCA) cycle. Evidence suggests that MPC downregulation in tumor cells impacts many aspects of tumorigenesis, including cancer cell-intrinsic (proliferation, invasiveness, stemness, resistance to therapy) and -extrinsic (angiogenesis, anti-tumor immune activity) properties. In many cancers, but not in all, MPC downregulation is associated with poor survival. MPC regulation is therefore central to tackling glycolysis in tumors. Abstract Pyruvate is a key molecule in the metabolic fate of mammalian cells; it is the crossroads from where metabolism proceeds either oxidatively or ends with the production of lactic acid. Pyruvate metabolism is regulated by many enzymes that together control carbon flux. Mitochondrial pyruvate carrier (MPC) is responsible for importing pyruvate from the cytosol to the mitochondrial matrix, where it is oxidatively phosphorylated to produce adenosine triphosphate (ATP) and to generate intermediates used in multiple biosynthetic pathways. MPC activity has an important role in glucose homeostasis, and its alteration is associated with diabetes, heart failure, and neurodegeneration. In cancer, however, controversy surrounds MPC function. In some cancers, MPC upregulation appears to be associated with a poor prognosis. However, most transformed cells undergo a switch from oxidative to glycolytic metabolism, the so-called Warburg effect, which, amongst other possibilities, is induced by MPC malfunction or downregulation. Consequently, impaired MPC function might induce tumors with strong proliferative, migratory, and invasive capabilities. Moreover, glycolytic cancer cells secrete lactate, acidifying the microenvironment, which in turn induces angiogenesis, immunosuppression, and the expansion of stromal cell populations supporting tumor growth. This review examines the latest findings regarding the tumorigenic processes affected by MPC.
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Rosencrans WM, Rajendran M, Bezrukov SM, Rostovtseva TK. VDAC regulation of mitochondrial calcium flux: From channel biophysics to disease. Cell Calcium 2021; 94:102356. [PMID: 33529977 PMCID: PMC7914209 DOI: 10.1016/j.ceca.2021.102356] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 01/06/2021] [Accepted: 01/06/2021] [Indexed: 12/14/2022]
Abstract
Voltage-dependent anion channel (VDAC), the most abundant mitochondrial outer membrane protein, is important for a variety of mitochondrial functions including metabolite exchange, calcium transport, and apoptosis. While VDAC's role in shuttling metabolites between the cytosol and mitochondria is well established, there is a growing interest in understanding the mechanisms of its regulation of mitochondrial calcium transport. Here we review the current literature on VDAC's role in calcium signaling, its biophysical properties, physiological function, and pathology focusing on its importance in cardiac diseases. We discuss the specific biophysical properties of the three VDAC isoforms in mammalian cells-VDAC 1, 2, and 3-in relationship to calcium transport and their distinct roles in cell physiology and disease. Highlighting the emerging evidence that cytosolic proteins interact with VDAC and regulate its calcium permeability, we advocate for continued investigation into the VDAC interactome at the contact sites between mitochondria and organelles and its role in mitochondrial calcium transport.
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Affiliation(s)
- William M Rosencrans
- Section on Molecular Transport, Eunice Kennedy Shriver. National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Megha Rajendran
- Section on Molecular Transport, Eunice Kennedy Shriver. National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Sergey M Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver. National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, United States
| | - Tatiana K Rostovtseva
- Section on Molecular Transport, Eunice Kennedy Shriver. National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, United States.
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Abstract
The evolution of the eukaryotic cell from the primal endosymbiotic event involved a complex series of adaptations driven primarily by energy optimization. Transfer of genes from endosymbiont to host and concomitant expansion (by infolding) of the endosymbiont's chemiosmotic membrane greatly increased output of adenosine triphosphate (ATP) and placed selective pressure on the membrane at the host-endosymbiont interface to sustain the energy advantage. It is hypothesized that critical functions at this interface (metabolite exchange, polypeptide import, barrier integrity to proteins and DNA) were managed by a precursor β-barrel protein ("pβB") from which the voltage-dependent anion-selective channel (VDAC) descended. VDAC's role as hub for disparate and increasingly complex processes suggests an adaptability that likely springs from a feature inherited from pβB, retained because of important advantages conferred. It is proposed that this property is the remarkable structural flexibility evidenced in VDAC's gating mechanism, a possible origin of which is discussed.
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Affiliation(s)
- Carmen A Mannella
- Department of Physiology, Center for Biomedical Engineering and Technology, University of Maryland School of Medicine, Baltimore, MD 20201, USA
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25
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Rosencrans WM, Aguilella VM, Rostovtseva TK, Bezrukov SM. α-Synuclein emerges as a potent regulator of VDAC-facilitated calcium transport. Cell Calcium 2021; 95:102355. [PMID: 33578201 DOI: 10.1016/j.ceca.2021.102355] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 01/04/2021] [Indexed: 02/06/2023]
Abstract
Voltage-dependent anion channel (VDAC) is the most ubiquitous channel at the mitochondrial outer membrane, and is believed to be the pathway for calcium entering or leaving the mitochondria. Therefore, understanding the molecular mechanisms of how VDAC regulates calcium influx and efflux from the mitochondria is of particular interest for mitochondrial physiology. When the Parkinson's disease (PD) related neuronal protein, alpha-synuclein (αSyn), is added to the reconstituted VDAC, it reversibly and partially blocks VDAC conductance by its acidic C-terminal tail. Using single-molecule VDAC electrophysiology of reconstituted VDAC we now demonstrate that, at CaCl2 concentrations below 150 mM, αSyn reverses the channel's selectivity from anionic to cationic. Importantly, we find that the decrease in channel conductance upon its blockage by αSyn is hugely overcompensated by a favorable change in the electrostatic environment for calcium, making the blocked state orders-of-magnitude more selective for calcium and thus increasing its net flux. -Our findings with higher calcium concentrations also demonstrate that the phenomenon of "charge inversion" is taking place at the level of a single polypeptide chain. Measurements of ion selectivity of three VDAC isoforms in CaCl2 gradient show that VDAC3 exhibits the highest calcium permeability among them, followed by VDAC2 and VDAC1, thus pointing to isoform-dependent physiological function. Mutation of the E73 residue - VDAC1 purported calcium binding site - shows that there is no measurable effect of the mutation in either open or αSyn-blocked VDAC1 states. Our results confirm VDACs involvement in calcium signaling and reveal a new regulatory role of αSyn, with clear implications for both normal calcium signaling and PD-associated mitochondrial dysfunction.
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Affiliation(s)
- William M Rosencrans
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Vicente M Aguilella
- Laboratory of Molecular Biophysics, Department of Physics, Universitat Jaume I, Av. Vicent Sos Baynat s/n 12071, Castellón, Spain
| | - Tatiana K Rostovtseva
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Sergey M Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, 20892, USA
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26
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Sander P, Gudermann T, Schredelseker J. A Calcium Guard in the Outer Membrane: Is VDAC a Regulated Gatekeeper of Mitochondrial Calcium Uptake? Int J Mol Sci 2021; 22:ijms22020946. [PMID: 33477936 PMCID: PMC7833399 DOI: 10.3390/ijms22020946] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/12/2021] [Accepted: 01/14/2021] [Indexed: 12/15/2022] Open
Abstract
Already in the early 1960s, researchers noted the potential of mitochondria to take up large amounts of Ca2+. However, the physiological role and the molecular identity of the mitochondrial Ca2+ uptake mechanisms remained elusive for a long time. The identification of the individual components of the mitochondrial calcium uniporter complex (MCUC) in the inner mitochondrial membrane in 2011 started a new era of research on mitochondrial Ca2+ uptake. Today, many studies investigate mitochondrial Ca2+ uptake with a strong focus on function, regulation, and localization of the MCUC. However, on its way into mitochondria Ca2+ has to pass two membranes, and the first barrier before even reaching the MCUC is the outer mitochondrial membrane (OMM). The common opinion is that the OMM is freely permeable to Ca2+. This idea is supported by the presence of a high density of voltage-dependent anion channels (VDACs) in the OMM, forming large Ca2+ permeable pores. However, several reports challenge this idea and describe VDAC as a regulated Ca2+ channel. In line with this idea is the notion that its Ca2+ selectivity depends on the open state of the channel, and its gating behavior can be modified by interaction with partner proteins, metabolites, or small synthetic molecules. Furthermore, mitochondrial Ca2+ uptake is controlled by the localization of VDAC through scaffolding proteins, which anchor VDAC to ER/SR calcium release channels. This review will discuss the possibility that VDAC serves as a physiological regulator of mitochondrial Ca2+ uptake in the OMM.
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Affiliation(s)
- Paulina Sander
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, 80336 Munich, Germany; (P.S.); (T.G.)
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, 80336 Munich, Germany; (P.S.); (T.G.)
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Partner Site Munich Heart Alliance, Munich, Germany
| | - Johann Schredelseker
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of Medicine, LMU Munich, 80336 Munich, Germany; (P.S.); (T.G.)
- Deutsches Zentrum für Herz-Kreislauf-Forschung, Partner Site Munich Heart Alliance, Munich, Germany
- Correspondence: ; Tel.: +49-(0)89-2180-73831
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Mitochondrial Structure and Bioenergetics in Normal and Disease Conditions. Int J Mol Sci 2021; 22:ijms22020586. [PMID: 33435522 PMCID: PMC7827222 DOI: 10.3390/ijms22020586] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 01/03/2021] [Accepted: 01/04/2021] [Indexed: 02/06/2023] Open
Abstract
Mitochondria are ubiquitous intracellular organelles found in almost all eukaryotes and involved in various aspects of cellular life, with a primary role in energy production. The interest in this organelle has grown stronger with the discovery of their link to various pathologies, including cancer, aging and neurodegenerative diseases. Indeed, dysfunctional mitochondria cannot provide the required energy to tissues with a high-energy demand, such as heart, brain and muscles, leading to a large spectrum of clinical phenotypes. Mitochondrial defects are at the origin of a group of clinically heterogeneous pathologies, called mitochondrial diseases, with an incidence of 1 in 5000 live births. Primary mitochondrial diseases are associated with genetic mutations both in nuclear and mitochondrial DNA (mtDNA), affecting genes involved in every aspect of the organelle function. As a consequence, it is difficult to find a common cause for mitochondrial diseases and, subsequently, to offer a precise clinical definition of the pathology. Moreover, the complexity of this condition makes it challenging to identify possible therapies or drug targets.
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VDAC Gating Thermodynamics, but Not Gating Kinetics, Are Virtually Temperature Independent. Biophys J 2020; 119:2584-2592. [PMID: 33189678 DOI: 10.1016/j.bpj.2020.10.039] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 10/06/2020] [Accepted: 10/16/2020] [Indexed: 12/17/2022] Open
Abstract
The voltage-dependent anion channel (VDAC) is the most abundant protein in the mitochondrial outer membrane and an archetypical β-barrel channel. Here, we study the effects of temperature on VDAC channels reconstituted in planar lipid membranes at the single- and multichannel levels within the 20°C to 40°C range. The temperature dependence of conductance measured on a single channel in 1 M KCl shows an increase characterized by a 10°C temperature coefficient Q10 = 1.22 ± 0.02, which exceeds that of the bathing electrolyte solution conductivity, Q10 = 1.17 ± 0.01. The rates of voltage-induced channel transition between the open and closed states measured on multichannel membranes also show statistically significant increases, with temperatures that are consistent with activation energy barriers of ∼10 ± 3 kcal/mol. At the same time, the gating thermodynamics, as characterized by the gating charge and voltage of equipartitioning, does not display any measurable temperature dependence. The two parameters stay within 3.2 ± 0.2 elementary charges and 30 ± 2 mV, respectively. Thus, whereas the channel kinetics, specifically its conductance and rates of gating response to voltage steps, demonstrates a clear increase with temperature, the conformational voltage-dependent equilibria are virtually insensitive to temperature. These results, which may be a general feature of β-barrel channel gating, suggest either an entropy-driven gating mechanism or a role for enthalpy-entropy compensation.
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29
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Modulation of the mitochondrial voltage-dependent anion channel (VDAC) by hydrogen peroxide and its recovery by curcumin. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2020; 49:661-672. [DOI: 10.1007/s00249-020-01469-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 09/25/2020] [Accepted: 10/05/2020] [Indexed: 11/26/2022]
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30
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Rovini A, Gurnev PA, Beilina A, Queralt-Martín M, Rosencrans W, Cookson MR, Bezrukov SM, Rostovtseva TK. Molecular mechanism of olesoxime-mediated neuroprotection through targeting α-synuclein interaction with mitochondrial VDAC. Cell Mol Life Sci 2020; 77:3611-3626. [PMID: 31760463 PMCID: PMC7244372 DOI: 10.1007/s00018-019-03386-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 10/23/2019] [Accepted: 11/13/2019] [Indexed: 01/03/2023]
Abstract
An intrinsically disordered neuronal protein α-synuclein (αSyn) is known to cause mitochondrial dysfunction, contributing to loss of dopaminergic neurons in Parkinson's disease. Through yet poorly defined mechanisms, αSyn crosses mitochondrial outer membrane and targets respiratory complexes leading to bioenergetics defects. Here, using neuronally differentiated human cells overexpressing wild-type αSyn, we show that the major metabolite channel of the outer membrane, the voltage-dependent anion channel (VDAC), is a pathway for αSyn translocation into the mitochondria. Importantly, the neuroprotective cholesterol-like synthetic compound olesoxime inhibits this translocation. By applying complementary electrophysiological and biophysical approaches, we provide mechanistic insights into the interplay between αSyn, VDAC, and olesoxime. Our data suggest that olesoxime interacts with VDAC β-barrel at the lipid-protein interface thus hindering αSyn translocation through the VDAC pore and affecting VDAC voltage gating. We propose that targeting αSyn translocation through VDAC could represent a key mechanism for the development of new neuroprotective strategies.
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Affiliation(s)
- Amandine Rovini
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bldg. 29B, Room 1G09, Bethesda, MD, 20892-0924, USA
- Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Philip A Gurnev
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bldg. 29B, Room 1G09, Bethesda, MD, 20892-0924, USA
| | - Alexandra Beilina
- Cell Biology and Gene Expression Section, Laboratory of Neurogenetics, National Institute of Aging, National Institutes of Health, Bethesda, MD, 20892, USA
| | - María Queralt-Martín
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bldg. 29B, Room 1G09, Bethesda, MD, 20892-0924, USA
| | - William Rosencrans
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bldg. 29B, Room 1G09, Bethesda, MD, 20892-0924, USA
- Colgate University, Hamilton, NY, 13346, USA
| | - Mark R Cookson
- Cell Biology and Gene Expression Section, Laboratory of Neurogenetics, National Institute of Aging, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Sergey M Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bldg. 29B, Room 1G09, Bethesda, MD, 20892-0924, USA
| | - Tatiana K Rostovtseva
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bldg. 29B, Room 1G09, Bethesda, MD, 20892-0924, USA.
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31
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Srivastava SR, Mahalakshmi R. Evolutionary selection of a 19-stranded mitochondrial β-barrel scaffold bears structural and functional significance. J Biol Chem 2020; 295:14653-14665. [PMID: 32817169 PMCID: PMC7586230 DOI: 10.1074/jbc.ra120.014366] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 08/15/2020] [Indexed: 12/12/2022] Open
Abstract
Transmembrane β-barrels of eukaryotic outer mitochondrial membranes (OMMs) are major channels of communication between the cytosol and mitochondria and are indispensable for cellular homeostasis. A structurally intriguing exception to all known transmembrane β-barrels is the unique odd-stranded, i.e. 19-stranded, structures found solely in the OMM. The molecular origins of this 19-stranded structure and its associated functional significance are unclear. In humans, the most abundant OMM transporter is the voltage-dependent anion channel. Here, using the human voltage-dependent anion channel as our template scaffold, we designed and engineered odd- and even-stranded structures of smaller (V216, V217, V218) and larger (V220, V221) barrel diameters. Determination of the structure, dynamics, and energetics of these engineered structures in bilayer membranes reveals that the 19-stranded barrel surprisingly holds modest to low stability in a lipid-dependent manner. However, we demonstrate that this structurally metastable protein possesses superior voltage-gated channel regulation, efficient mitochondrial targeting, and in vivo cell survival, with lipid-modulated stability, all of which supersede the occurrence of a metastable 19-stranded scaffold. We propose that the unique structural adaptation of these transmembrane transporters exclusively in mitochondria bears strong evolutionary basis and is functionally significant for homeostasis.
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Affiliation(s)
- Shashank Ranjan Srivastava
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, India
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhopal, India.
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32
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Zhang L, Townsend DM, Morris M, Maldonado EN, Jiang YL, Broome AM, Bethard JR, Ball LE, Tew KD. Voltage-Dependent Anion Channels Influence Cytotoxicity of ME-344, a Therapeutic Isoflavone. J Pharmacol Exp Ther 2020; 374:308-318. [PMID: 32546528 PMCID: PMC7372917 DOI: 10.1124/jpet.120.000009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 05/19/2020] [Indexed: 01/27/2023] Open
Abstract
ME-344 is a second-generation cytotoxic isoflavone with anticancer activity promulgated through interference with mitochondrial functions. Using a click chemistry version of the drug together with affinity-enriched mass spectrometry, voltage-dependent anion channels (VDACs) 1 and 2 were identified as drug targets. To determine the importance of VDAC1 or 2 to cytotoxicity, we used lung cancer cells that were either sensitive (H460) or intrinsically resistant (H596) to the drug. In H460 cells, depletion of VDAC1 and VDAC2 by small interfering RNA impacted ME-344 effects by diminishing generation of reactive oxygen species (ROS), preventing mitochondrial membrane potential dissipation, and moderating ME-344-induced cytotoxicity and mitochondrial-mediated apoptosis. Mechanistically, VDAC1 and VDAC2 knockdown prevented ME-344-induced apoptosis by inhibiting Bax mitochondrial translocation and cytochrome c release as well as apoptosis in these H460 cells. We conclude that VDAC1 and 2, as mediators of the response to oxidative stress, have roles in modulating ROS generation, Bax translocation, and cytochrome c release during mitochondrial-mediated apoptosis caused by ME-344. SIGNIFICANCE STATEMENT: Dissecting preclinical drug mechanisms are of significance in development of a drug toward eventual Food and Drug Administration approval.
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Affiliation(s)
- Leilei Zhang
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Danyelle M Townsend
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Morgan Morris
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Eduardo N Maldonado
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Yu-Lin Jiang
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Ann-Marie Broome
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Jennifer R Bethard
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Lauren E Ball
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
| | - Kenneth D Tew
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics (L.Z., M.M., E.N.M., Y.-L.J., A.-M.B., J.R.B., L.E.B., K.D.T.) and Department of Pharmaceutical and Biomedical Sciences (D.M.T.), Medical University of South Carolina, Charleston, South Carolina
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Wilting F, Kopp R, Gurnev PA, Schedel A, Dupper NJ, Kwon O, Nicke A, Gudermann T, Schredelseker J. The antiarrhythmic compound efsevin directly modulates voltage-dependent anion channel 2 by binding to its inner wall and enhancing mitochondrial Ca 2+ uptake. Br J Pharmacol 2020; 177:2947-2958. [PMID: 32059260 PMCID: PMC7279994 DOI: 10.1111/bph.15022] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 01/20/2020] [Accepted: 01/29/2020] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND AND PURPOSE The synthetic compound efsevin was recently identified to suppress arrhythmogenesis in models of cardiac arrhythmia, making it a promising candidate for antiarrhythmic therapy. Its activity was shown to be dependent on the voltage-dependent anion channel 2 (VDAC2) in the outer mitochondrial membrane. Here, we investigated the molecular mechanism of the efsevin-VDAC2 interaction. EXPERIMENTAL APPROACH To evaluate the functional interaction of efsevin and VDAC2, we measured currents through recombinant VDAC2 in planar lipid bilayers. Using molecular ligand-protein docking and mutational analysis, we identified the efsevin binding site on VDAC2. Finally, physiological consequences of the efsevin-induced modulation of VDAC2 were analysed in HL-1 cardiomyocytes. KEY RESULTS In lipid bilayers, efsevin reduced VDAC2 conductance and shifted the channel's open probability towards less anion-selective closed states. Efsevin binds to a binding pocket formed by the inner channel wall and the pore-lining N-terminal α-helix. Exchange of amino acids N207, K236 and N238 within this pocket for alanines abolished the channel's efsevin-responsiveness. Upon heterologous expression in HL-1 cardiomyocytes, both channels, wild-type VDAC2 and the efsevin-insensitive VDAC2AAA restored mitochondrial Ca2+ uptake, but only wild-type VDAC2 was sensitive to efsevin. CONCLUSION AND IMPLICATIONS In summary, our data indicate a direct interaction of efsevin with VDAC2 inside the channel pore that leads to modified gating and results in enhanced SR-mitochondria Ca2+ transfer. This study sheds new light on the function of VDAC2 and provides a basis for structure-aided chemical optimization of efsevin.
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Affiliation(s)
- Fabiola Wilting
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of MedicineLMU MunichMunichGermany
| | - Robin Kopp
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of MedicineLMU MunichMunichGermany
| | - Philip A. Gurnev
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human DevelopmentNational Institutes of HealthBethesdaMaryland
| | - Anna Schedel
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of MedicineLMU MunichMunichGermany
| | - Nathan J. Dupper
- Department of Chemistry and BiochemistryUniversity of California Los AngelesLos AngelesCalifornia
| | - Ohyun Kwon
- Department of Chemistry and BiochemistryUniversity of California Los AngelesLos AngelesCalifornia
| | - Annette Nicke
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of MedicineLMU MunichMunichGermany
| | - Thomas Gudermann
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of MedicineLMU MunichMunichGermany
- Deutsches Zentrum für Herz‐Kreislauf‐Forschung (DZHK)Partner Site Munich Heart Alliance (MHA)MunichGermany
| | - Johann Schredelseker
- Walther Straub Institute of Pharmacology and Toxicology, Faculty of MedicineLMU MunichMunichGermany
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Cryo-Electron Microscopy and Correlation Averaging of Frozen-Hydrated, Polymorphic 2D Crystals of the Mitochondrial Outer Membrane Channel. ACTA ACUST UNITED AC 2020. [DOI: 10.1017/s0424820100179257] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Voltage-dependent, anion-selective channels (VDAC) are formed in the mitochondrial outer membrane (mitOM) by a 30-kDa polypeptide. These channels form ordered 2D arrays when mitOMs from Neurospora crassa are treated with soluble phospholipase A2. We obtain low-dose electron microscopic images of unstained specimens of VDAC crystals preserved in vitreous ice, using a Philips EM420 equipped with a Gatan cryo-transfer stage. We then use correlation analysis to compute average projections of the channel crystals. The procedure involves Fourier-filtration of a region within a crystal field to obtain a preliminary average that is subsequently cross-correlated with the entire crystal. Subregions are windowed from the crystal image at coordinates of peaks in the cross-correlation function (CCF, see Figures 1 and 2) and summed to form averages (Figure 3).The VDAC channel forms several different types of crystalline arrays in mitOMs. The polymorph first observed during phospholipase treatment is a parallelogram array (a=13 run, b=11.5 run, θ==109°) containing 6 water-filled pores per unit cell. Figure 1 shows the CCF of a sub-field of such an “oblique” array used to compute the correlation average of Figure 3A. With increased phospholipase treatment, other polymorphs are observed, often co-existing within the same crystal. For example, two distinct (but closely related) types of lattices occur in the field corresponding to the CCF of Figure 2: a “contracted” version of the parallelogram lattice (a=13 run, b=10 run, θ=99°), and a near-rectangular lattice (a=8.5 run, b=5 nm). The pattern of maxima in this CCF suggests that a third, near-hexagonal lattice (a=4.5 nm) may also be present. The correlation averages of Figures 3B-D were computed from polycrystalline fields, using peak coordinates in regions of CCFs corresponding to each of the three lattice types.
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Rostovtseva TK, Queralt-Martín M, Rosencrans WM, Bezrukov SM. Targeting the Multiple Physiologic Roles of VDAC With Steroids and Hydrophobic Drugs. Front Physiol 2020; 11:446. [PMID: 32457654 PMCID: PMC7221028 DOI: 10.3389/fphys.2020.00446] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/09/2020] [Indexed: 12/12/2022] Open
Abstract
There is accumulating evidence that endogenous steroids and non-polar drugs are involved in the regulation of mitochondrial physiology. Many of these hydrophobic compounds interact with the Voltage Dependent Anion Channel (VDAC). This major metabolite channel in the mitochondrial outer membrane (MOM) regulates the exchange of ions and water-soluble metabolites, such as ATP and ADP, across the MOM, thus governing mitochondrial respiration. Proteomics and biochemical approaches together with molecular dynamics simulations have identified an impressively large number of non-polar compounds, including endogenous, able to bind to VDAC. These findings have sparked speculation that both natural steroids and synthetic hydrophobic drugs regulate mitochondrial physiology by directly affecting VDAC ion channel properties and modulating its metabolite permeability. Here we evaluate recent studies investigating the effect of identified VDAC-binding natural steroids and non-polar drugs on VDAC channel functioning. We argue that while many compounds are found to bind to the VDAC protein, they do not necessarily affect its channel functions in vitro. However, they may modify other aspects of VDAC physiology such as interaction with its cytosolic partner proteins or complex formation with other mitochondrial membrane proteins, thus altering mitochondrial function.
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Affiliation(s)
- Tatiana K Rostovtseva
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - María Queralt-Martín
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - William M Rosencrans
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
| | - Sergey M Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, United States
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Kanwar P, Samtani H, Sanyal SK, Srivastava AK, Suprasanna P, Pandey GK. VDAC and its interacting partners in plant and animal systems: an overview. Crit Rev Biotechnol 2020; 40:715-732. [PMID: 32338074 DOI: 10.1080/07388551.2020.1756214] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Molecular trafficking between different subcellular compartments is the key for normal cellular functioning. Voltage-dependent anion channels (VDACs) are small-sized proteins present in the outer mitochondrial membrane, which mediate molecular trafficking between mitochondria and cytoplasm. The conductivity of VDAC is dependent on the transmembrane voltage, its oligomeric state and membrane lipids. VDAC acts as a convergence point to a diverse variety of mitochondrial functions as well as cell survival. This functional diversity is attained due to their interaction with a plethora of proteins inside the cell. Although, there are hints toward functional conservation/divergence between animals and plants; knowledge about the functional role of the VDACs in plants is still limited. We present here a comparative overview to provide an integrative picture of the interactions of VDAC with different proteins in both animals and plants. Also discussed are their physiological functions from the perspective of cellular movements, signal transduction, cellular fate, disease and development. This in-depth knowledge of the biological importance of VDAC and its interacting partner(s) will assist us to explore their function in the applied context in both plant and animal.
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Affiliation(s)
- Poonam Kanwar
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Harsha Samtani
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Sibaji K Sanyal
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Ashish K Srivastava
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Penna Suprasanna
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Girdhar K Pandey
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
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37
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Calabrò E, Magazù S, Currò M, Ientile R. The inverse relation between mitochondrial transmembrane potential and proteins α-helix in neuronal-like cells under static magnetic field and the role of VDAC. Electromagn Biol Med 2020; 39:176-182. [PMID: 32149540 DOI: 10.1080/15368378.2020.1737808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
In this study, a correlation between cell channel α-helices displacement and the mitochondrial transmembrane potential after exposure of 3, 7, 15 and 24 h of neuronal-like cells to a uniform magnetic field at the intensity of 2 mT was shown. Fourier Transform Infrared (FTIR) Spectroscopy and fluorescence techniques were used to analyze the secondary structure of protein content and mitochondrial transmembrane potential, respectively. The main result of this study was represented by a significant inverse relation between the mitochondrial transmembrane potential and the intensity of the Amide I band that can be associated with time exposure. Given that mitochondrial transmembrane potential should be related to the gating state of voltage-dependent anion channel (VDAC) in mitochondrial membrane, this result could have a relevant role in medicine. Indeed, VDAC's irregular behavior can be associated with several varieties of mitochondria-associated pathologies and various forms of cancer and neurodegeneration.
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Affiliation(s)
- Emanuele Calabrò
- Department of Mathematical and Informatics Sciences, Physical Sciences and Earth Sciences of Messina University, Messina, Italy
| | - Salvatore Magazù
- Department of Mathematical and Informatics Sciences, Physical Sciences and Earth Sciences of Messina University, Messina, Italy.,Department of Biochemical and Dental Sciences and Morphological and Functional Image, University of Messina, Messina, Italy.,Le Studium, Loire Valley Institute for Advanced Studies, Orléans & Tours, France.,Centre de Biophysique Moleculaire (CBM), rue Charles Sandron, Laboratoire Interfaces, Confinement, Materiaux et Nanostructures (ICMN) - UMR 7374 CNRS, Université d'Orleans, Orleans, France.,INDAM - Gruppo Nazionale per la Fisica Matematica - GNFM, Istituto Nazionale di Alta Matematica "F. Severi, Rome, Italy
| | - Monica Currò
- Department of Biochemical and Dental Sciences and Morphological and Functional Image, University of Messina, Messina, Italy
| | - Riccardo Ientile
- Department of Biochemical and Dental Sciences and Morphological and Functional Image, University of Messina, Messina, Italy
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38
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Malik C, Ghosh S. Quinidine partially blocks mitochondrial voltage-dependent anion channel (VDAC). EUROPEAN BIOPHYSICS JOURNAL: EBJ 2020; 49:193-205. [DOI: 10.1007/s00249-020-01426-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Revised: 02/12/2020] [Accepted: 02/17/2020] [Indexed: 02/07/2023]
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39
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Böhm R, Amodeo GF, Murlidaran S, Chavali S, Wagner G, Winterhalter M, Brannigan G, Hiller S. The Structural Basis for Low Conductance in the Membrane Protein VDAC upon β-NADH Binding and Voltage Gating. Structure 2020; 28:206-214.e4. [PMID: 31862297 PMCID: PMC8353649 DOI: 10.1016/j.str.2019.11.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 09/27/2019] [Accepted: 11/26/2019] [Indexed: 11/26/2022]
Abstract
The voltage-dependent anion channel (VDAC) forms the primary diffusion pore of the outer mitochondrial membrane. In its apo form, VDAC adopts an open conformation with high conductance. States of lower conductance can be induced by ligand binding or the application of voltage. Here, we clarify at the atomic level how β-NADH binding leads to a low-conductance state and characterize the role of the VDAC N-terminal helix in voltage gating. A high-resolution NMR structure of human VDAC-1 with bound NADH, combined with molecular dynamics simulation show that β-NADH binding reduces the pore conductance sterically without triggering a structural change. Electrophysiology recordings of crosslinked protein variants and NMR relaxation experiments probing different time scales show that increased helix dynamics is present in the open state and that motions of the N-terminal helices are involved in the VDAC voltage gating mechanism.
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Affiliation(s)
- Raphael Böhm
- Biozentrum, University of Basel, Basel 4056, Switzerland
| | | | - Sruthi Murlidaran
- Center for Computational Biology, Rutgers University, Camden, NJ 08102, USA
| | - Shashank Chavali
- Department of Biology, Rutgers University, Camden, NJ 08201, USA
| | - Gerhard Wagner
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Grace Brannigan
- Center for Computational Biology, Rutgers University, Camden, NJ 08102, USA; Department of Physics, Center for Computational and Integrative Biology, Rutgers University, Camden, NJ 08201, USA
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40
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Ortega-Sánchez R, Camacho-Nuez M, Castañeda-Ortiz EJ, Martínez-Benítez MB, Hernández-Silva DJ, Aguilar-Tipacamú G, Mosqueda J. Vaccine efficacy of recombinant BmVDAC on Rhipicephalus microplus fed on Babesia bigemina-infected and uninfected cattle. Vaccine 2020; 38:3618-3625. [PMID: 31928853 DOI: 10.1016/j.vaccine.2019.12.040] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2019] [Revised: 12/09/2019] [Accepted: 12/17/2019] [Indexed: 12/16/2022]
Abstract
Rhipicephalus microplus is the most widely distributed tick worldwide and causes significant economic losses in the livestock industry. It directly affects hosts (especially in large infestations) by feeding on blood and piercing the skin and indirectly affects hosts as a vector of pathogens that cause infectious diseases, such as bovine babesiosis. Current research on the control of ticks is focused on integrated tick control programmes, including vaccination treatment with acaricides and completely blocking pathogen transmission. Our previous studies showed that R. microplus VDAC (BmVDAC) expression is modulated by Babesia bigemina infection. VDAC is a mitochondrial protein with multiple functions in addition to its primary role as a central component of the apoptotic machinery. In this paper, we evaluated BmVDAC as an anti-tick vaccine and its capacity to block the infection of Babesia bigemina in ticks. Our results demonstrate that rBmVDAC is immunogenic and that antibodies specifically recognize the native protein from midguts of R. microplus. Immunization with rBmVDAC afforded an 82% efficacy against R. microplus infestation in the group of vaccinated cattle compared with the control group. In contrast, rBmVDAC showed a lower efficacy of 34% against tick infestation in cattle vaccinated with rBmVDAC, infested with R. microplus and infected with B. bigemina. The main effect on ticks fed in vaccinated and infected cattle was a 34% reduction in egg fertility (DF) compared to ticks fed on the control group. There was no reduction in the B. bigemina parasite levels of ticks fed on rBmVDAC-vaccinated cattle. These results suggest that the rBmVDAC protein could be tested as a vaccine for the control of tick infestation.
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Affiliation(s)
- Reyna Ortega-Sánchez
- Immunology and Vaccines Laboratory, C.A. Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Carretera a Chichimequillas, Ejido Bolaños, Queretaro Queretaro 76140, Mexico; Maestria en Salud y Producción Animal Sustentable, Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Querétaro, Qro, Mexico
| | - Minerva Camacho-Nuez
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, San Lorenzo Núm. 290, esquina Roberto Gayol, colonia del Valle Sur, delegación Benito Juárez, México D.F. C.P. 03100, Mexico.
| | - Elizabeth Jacqueline Castañeda-Ortiz
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, San Lorenzo Núm. 290, esquina Roberto Gayol, colonia del Valle Sur, delegación Benito Juárez, México D.F. C.P. 03100, Mexico
| | - Máximo Berto Martínez-Benítez
- Posgrado en Ciencias Genómicas, Universidad Autónoma de la Ciudad de México, San Lorenzo Núm. 290, esquina Roberto Gayol, colonia del Valle Sur, delegación Benito Juárez, México D.F. C.P. 03100, Mexico
| | - Diego Josimar Hernández-Silva
- Immunology and Vaccines Laboratory, C.A. Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Carretera a Chichimequillas, Ejido Bolaños, Queretaro Queretaro 76140, Mexico
| | - Gabriela Aguilar-Tipacamú
- Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Av. de las Ciencias s/n, Col Juriquilla C.P. 76230, Queretaro, Mexico
| | - Juan Mosqueda
- Immunology and Vaccines Laboratory, C.A. Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Carretera a Chichimequillas, Ejido Bolaños, Queretaro Queretaro 76140, Mexico; Facultad de Ciencias Naturales, Universidad Autónoma de Querétaro, Av. de las Ciencias s/n, Col Juriquilla C.P. 76230, Queretaro, Mexico.
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Cheng WW, Budelier MM, Sugasawa Y, Bergdoll L, Queralt-Martín M, Rosencrans W, Rostovtseva TK, Chen ZW, Abramson J, Krishnan K, Covey DF, Whitelegge JP, Evers AS. Multiple neurosteroid and cholesterol binding sites in voltage-dependent anion channel-1 determined by photo-affinity labeling. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:1269-1279. [PMID: 31176038 PMCID: PMC6681461 DOI: 10.1016/j.bbalip.2019.06.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 05/23/2019] [Accepted: 06/02/2019] [Indexed: 12/31/2022]
Abstract
Voltage-dependent anion channel-1 (VDAC1) is a mitochondrial porin that is implicated in cellular metabolism and apoptosis, and modulated by numerous small molecules including lipids. VDAC1 binds sterols, including cholesterol and neurosteroids such as allopregnanolone. Biochemical and computational studies suggest that VDAC1 binds multiple cholesterol molecules, but photolabeling studies have identified only a single cholesterol and neurosteroid binding site at E73. To identify all the binding sites of neurosteroids in VDAC1, we apply photo-affinity labeling using two sterol-based photolabeling reagents with complementary photochemistry: 5α-6-AziP which contains an aliphatic diazirine, and KK200 which contains a trifluoromethyl-phenyldiazirine (TPD) group. 5α-6-AziP and KK200 photolabel multiple residues within an E73 pocket confirming the presence of this site and mapping sterol orientation within this pocket. In addition, KK200 photolabels four other sites consistent with the finding that VDAC1 co-purifies with five cholesterol molecules. Both allopregnanolone and cholesterol competitively prevent photolabeling at E73 and three other sites indicating that these are common sterol binding sites shared by both neurosteroids and cholesterol. Binding at the functionally important residue E73 suggests a possible role for sterols in regulating VDAC1 signaling and interaction with partner proteins.
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Affiliation(s)
- Wayland W.L. Cheng
- Department of Anesthesiology, Washington University in St. Louis, MO 63110, USA
| | - Melissa M. Budelier
- Department of Anesthesiology, Washington University in St. Louis, MO 63110, USA,Department of Biochemistry and Molecular Biophysics, Washington University in St. Louis, MO 63110, USA
| | - Yusuke Sugasawa
- Department of Anesthesiology, Washington University in St. Louis, MO 63110, USA
| | - Lucie Bergdoll
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - María Queralt-Martín
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - William Rosencrans
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tatiana K. Rostovtseva
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Zi-Wei Chen
- Department of Anesthesiology, Washington University in St. Louis, MO 63110, USA,Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis, MO 63110, USA
| | - Jeff Abramson
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Kathiresan Krishnan
- Department of Developmental Biology, Washington University in St. Louis, MO 63110, USA
| | - Douglas F. Covey
- Department of Anesthesiology, Washington University in St. Louis, MO 63110, USA,Department of Developmental Biology, Washington University in St. Louis, MO 63110, USA,Department of Psychiatry, Washington University in St. Louis, MO 63110, USA,Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis, MO 63110, USA
| | - Julian P. Whitelegge
- Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA
| | - Alex S. Evers
- Department of Anesthesiology, Washington University in St. Louis, MO 63110, USA,Department of Developmental Biology, Washington University in St. Louis, MO 63110, USA,Department of Psychiatry, Washington University in St. Louis, MO 63110, USA,Taylor Family Institute for Innovative Psychiatric Research, Washington University in St. Louis, MO 63110, USA,Corresponding author at: Department of Anesthesiology, Washington University School of Medicine, Campus Box 8054, St. Louis, MO 63110, USA. (A.S. Evers)
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42
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Fan K, Fan Z, Cheng H, Huang Q, Yang C, Jin K, Luo G, Yu X, Liu C. Hexokinase 2 dimerization and interaction with voltage-dependent anion channel promoted resistance to cell apoptosis induced by gemcitabine in pancreatic cancer. Cancer Med 2019; 8:5903-5915. [PMID: 31426130 PMCID: PMC6792491 DOI: 10.1002/cam4.2463] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 06/12/2019] [Accepted: 06/29/2019] [Indexed: 12/12/2022] Open
Abstract
Gemcitabine (GEM) is the standard chemotherapy drug for pancreatic cancer. Because of widespread drug resistance, the effect is limited. Therefore, it is urgent to reveal the underlying mechanism. Glycolysis is the most remarkable character of tumor aberrant metabolism, which plays vital roles on tumor drug resistance. Hexokinase 2 (HK2), as the key enzyme regulating the first‐step reaction of glycolysis, is overexpressed in many kinds of tumors. The putative role of HK2 resisting GEM therapy was investigated in this study. We found that HK2 was overexpressed in pancreatic cancer and associated with poor prognosis. HK2 knockdown decreased pancreatic cancer cell proliferation, migration viability, and promoted cell apoptosis in vitro. HK2 high expression in pancreatic cancer showed GEM resistance. HK2 knockdown increased the sensitivity of pancreatic cancer cell to GEM, the growth of xenograft tumor with HK2 knockdown was also further decreased with the GEM treatment compared with control in vivo. GEM‐resistant pancreatic cancer showed the increase of HK2 dimer rather than HK2 mRNA or protein. Our study revealed that the ROS derived from GEM promoted HK2 dimerization combining with voltage‐dependent anion channel, which resulted in the resistance to GEM. Meanwhile, our study established a new sight for GEM resistance in pancreatic cancer.
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Affiliation(s)
- Kun Fan
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China.,Shanghai Pancreatic Cancer Institute, Shanghai, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Zhiyao Fan
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China.,Shanghai Pancreatic Cancer Institute, Shanghai, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - He Cheng
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China.,Shanghai Pancreatic Cancer Institute, Shanghai, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Qiuyi Huang
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China.,Shanghai Pancreatic Cancer Institute, Shanghai, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Chao Yang
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China.,Shanghai Pancreatic Cancer Institute, Shanghai, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Kaizhou Jin
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China.,Shanghai Pancreatic Cancer Institute, Shanghai, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Guopei Luo
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China.,Shanghai Pancreatic Cancer Institute, Shanghai, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Xianjun Yu
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China.,Shanghai Pancreatic Cancer Institute, Shanghai, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
| | - Chen Liu
- Department of Pancreatic Surgery, Fudan University Shanghai Cancer Center, Shanghai, P.R. China.,Department of Oncology, Shanghai Medical College, Fudan University, Shanghai, P.R. China.,Shanghai Pancreatic Cancer Institute, Shanghai, P.R. China.,Pancreatic Cancer Institute, Fudan University, Shanghai, P.R. China
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Reif MM, Fischer M, Fredriksson K, Hagn F, Zacharias M. The N-Terminal Segment of the Voltage-Dependent Anion Channel: A Possible Membrane-Bound Intermediate in Pore Unbinding. J Mol Biol 2019; 431:223-243. [DOI: 10.1016/j.jmb.2018.09.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 09/11/2018] [Accepted: 09/26/2018] [Indexed: 12/25/2022]
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44
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Queralt-Martín M, Bergdoll L, Jacobs D, Bezrukov SM, Abramson J, Rostovtseva TK. Assessing the role of residue E73 and lipid headgroup charge in VDAC1 voltage gating. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2019; 1860:22-29. [PMID: 30412693 PMCID: PMC8283775 DOI: 10.1016/j.bbabio.2018.11.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Revised: 10/05/2018] [Accepted: 11/04/2018] [Indexed: 12/25/2022]
Abstract
The voltage-dependent anion channel (VDAC) is the most abundant protein of the mitochondrial outer membrane (MOM) where it regulates transport of ions and metabolites in and out of the organelle. VDAC function is extensively studied in a lipid bilayer system that allows conductance monitoring of reconstituted channels under applied voltage. The process of switching from a high-conductance state, open to metabolites, to a variety of low-conducting states, which excludes metabolite transport, is termed voltage gating and the mechanism remains poorly understood. Recent studies have implicated the involvement of the membrane-solvated residue E73 in the gating process through β-barrel destabilization. However, there has been no direct experimental evidence of E73 involvement in VDAC1 voltage gating. Here, using electrophysiology measurements, we exclude the involvement of E73 in murine VDAC1 (mVDAC1) voltage gating process. With an established protocol of assessing voltage gating of VDACs reconstituted into planar lipid membranes, we definitively show that mVDAC1 gating properties do not change when E73 is replaced by either a glutamine or an alanine. We further demonstrate that cholesterol has no effect on mVDAC1 gating characteristics, though it was shown that E73 is coordinating residue in the cholesterol binding site. In contrast, we found a pronounced gating effect based on the charge of the phospholipid headgroup, where the positive charge stimulates and negative charge suppresses gating. These findings call for critical evaluation of the existing models of VDAC gating and contribute to our understanding of VDAC's role in control of MOM permeability and regulation of mitochondrial respiration and metabolism.
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Affiliation(s)
- María Queralt-Martín
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA.
| | - Lucie Bergdoll
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA.
| | - Daniel Jacobs
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Sergey M. Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jeff Abramson
- Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095, USA.
| | - Tatiana K. Rostovtseva
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA,To whom correspondence should be addressed: Tatiana K. Rostovtseva, Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 9000 Rockville Pike, Bldg. 9, Room 1E-106, Bethesda, MD 20892-0924. Phone: (301) 402-4702, ; Jeff Abramson, Department of Physiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA 90095. Phone: (310) 825-3913,
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Hoogerheide DP, Noskov SY, Kuszak AJ, Buchanan SK, Rostovtseva TK, Nanda H. Structure of voltage-dependent anion channel-tethered bilayer lipid membranes determined using neutron reflectivity. Acta Crystallogr D Struct Biol 2018; 74:1219-1232. [PMID: 30605136 PMCID: PMC6317592 DOI: 10.1107/s2059798318011749] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Accepted: 08/20/2018] [Indexed: 01/05/2023] Open
Abstract
Neutron reflectivity (NR) has emerged as a powerful technique to study the structure and behavior of membrane proteins at planar lipid interfaces. Integral membrane proteins (IMPs) remain a significant challenge for NR owing to the difficulty of forming complete bilayers with sufficient protein density for scattering techniques. One strategy to achieve high protein density on a solid substrate is the capture of detergent-stabilized, affinity-tagged IMPs on a nitrilotriacetic acid (NTA)-functionalized self-assembled monolayer (SAM), followed by reconstitution into the lipids of interest. Such protein-tethered bilayer lipid membranes (ptBLMs) have the notable advantage of a uniform IMP orientation on the substrate. Here, NR is used to provide a structural characterization of the ptBLM process from formation of the SAM to capture of the detergent-stabilized IMP and lipid reconstitution. The mitochondrial outer-membrane voltage-dependent anion channel (VDAC), which controls the exchange of bioenergetic metabolites between mitochondria and the cytosol, was used as a model β-barrel IMP. Molecular dynamics simulations were used for comparison with the experimental results and to inform the parameters of the physical models describing the NR data. The detailed structure of the SAM is shown to depend on the density of the NTA chelating groups. The relative content of detergent and protein in surface-immobilized, detergent-stabilized VDAC is measured, while the reconstituted lipid bilayer is shown to be complete to within a few percent, using the known atomic structure of VDAC. Finally, excess lipid above the reconstituted bilayer, which is of consequence for more indirect structural and functional studies, is shown to be present.
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Affiliation(s)
- David P. Hoogerheide
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20878, USA
| | - Sergei Yu. Noskov
- Centre for Molecular Simulations and Department of Biological Sciences, University of Calgary, Calgary T2N 1N4, Canada
| | - Adam J. Kuszak
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Susan K. Buchanan
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Tatiana K. Rostovtseva
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA
| | - Hirsh Nanda
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20878, USA
- Physics Department, Carnegie Mellon University, Pittsburgh, PA 15213, USA
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46
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Van Liefferinge F, Krammer EM, Sengupta D, Prévost M. Lipid composition and salt concentration as regulatory factors of the anion selectivity of VDAC studied by coarse-grained molecular dynamics simulations. Chem Phys Lipids 2018; 220:66-76. [PMID: 30448398 DOI: 10.1016/j.chemphyslip.2018.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 11/08/2018] [Accepted: 11/12/2018] [Indexed: 12/27/2022]
Abstract
The voltage-dependent anion channel (VDAC) is a mitochondrial outer membrane protein whose fundamental function is to facilitate and regulate the flow of metabolites between the cytosol and the mitochondrial intermembrane space. Using coarse-grained molecular dynamics simulations, we investigated the dependence of VDAC selectivity towards small inorganic anions on two factors: the ionic strength and the lipid composition. In agreement with experimental data we found that VDAC becomes less anion selective with increasing salt concentration due to the screening of a few basic residues that point into the pore lumen. The molecular dynamics simulations provide insight into the regulation mechanism of VDAC selectivity by the composition in the lipid membrane and suggest that the ion distribution is differently modulated by POPE compared to the POPC bilayer. This occurs through the more persistent interactions of acidic residues located at both rims of the β-barrel with head groups of POPE which in turn impact the electrostatic potential and thereby the selectivity of the pore. This mechanism occurs not only in POPE single component membranes but also in a mixed POPE/POPC bilayer by an enrichment of POPE over POPC lipids on the surface of VDAC. Thus we show here that computationally-inexpensive coarse-grained simulations are able to capture, in a semi-quantitative way, essential features of VDAC anion selectivity and could pave the way toward a molecular level understanding of metabolite transport in natural membranes.
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Affiliation(s)
- F Van Liefferinge
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - E-M Krammer
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles (ULB), Brussels, Belgium
| | - D Sengupta
- CSIR-National Chemical Laboratory, Dr. Homi Bhabha Road, Pune, 411 008, India
| | - M Prévost
- Structure et Fonction des Membranes Biologiques, Université Libre de Bruxelles (ULB), Brussels, Belgium.
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47
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Kasimova MA, Lindahl E, Delemotte L. Determining the molecular basis of voltage sensitivity in membrane proteins. J Gen Physiol 2018; 150:1444-1458. [PMID: 30150239 PMCID: PMC6168238 DOI: 10.1085/jgp.201812086] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Accepted: 08/07/2018] [Indexed: 12/31/2022] Open
Abstract
The identification of voltage-sensing elements in membrane proteins is challenging due to the diversity of voltage-sensing mechanisms. Kasimova et al. present a computational approach to predict the elements involved in voltage sensing, which they validate using voltage-gated ion channels. Voltage-sensitive membrane proteins are united by their ability to transform changes in membrane potential into mechanical work. They are responsible for a spectrum of physiological processes in living organisms, including electrical signaling and cell-cycle progression. Although the mechanism of voltage-sensing has been well characterized for some membrane proteins, including voltage-gated ion channels, even the location of the voltage-sensing elements remains unknown for others. Moreover, the detection of these elements by using experimental techniques is challenging because of the diversity of membrane proteins. Here, we provide a computational approach to predict voltage-sensing elements in any membrane protein, independent of its structure or function. It relies on an estimation of the propensity of a protein to respond to changes in membrane potential. We first show that this property correlates well with voltage sensitivity by applying our approach to a set of voltage-sensitive and voltage-insensitive membrane proteins. We further show that it correctly identifies authentic voltage-sensitive residues in the voltage-sensor domain of voltage-gated ion channels. Finally, we investigate six membrane proteins for which the voltage-sensing elements have not yet been characterized and identify residues and ions that might be involved in the response to voltage. The suggested approach is fast and simple and enables a characterization of voltage sensitivity that goes beyond mere identification of charges. We anticipate that its application before mutagenesis experiments will significantly reduce the number of potential voltage-sensitive elements to be tested.
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Affiliation(s)
- Marina A Kasimova
- Department of Applied Physics, Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Erik Lindahl
- Department of Applied Physics, Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden.,Department of Biochemistry and Biophysics, Science for Life Laboratory, Stockholm University, Stockholm, Sweden
| | - Lucie Delemotte
- Department of Applied Physics, Science for Life Laboratory, KTH Royal Institute of Technology, Stockholm, Sweden
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48
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Kalu N, Atsmon-Raz Y, Momben Abolfath S, Lucas L, Kenney C, Leppla SH, Tieleman DP, Nestorovich EM. Effect of late endosomal DOBMP lipid and traditional model lipids of electrophysiology on the anthrax toxin channel activity. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2192-2203. [PMID: 30409515 DOI: 10.1016/j.bbamem.2018.08.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 07/09/2018] [Accepted: 08/19/2018] [Indexed: 01/26/2023]
Abstract
Anthrax toxin action requires triggering of natural endocytic transport mechanisms whereby the binding component of the toxin forms channels (PA63) within endosomal limiting and intraluminal vesicle membranes to deliver the toxin's enzymatic components into the cytosol. Membrane lipid composition varies at different stages of anthrax toxin internalization, with intraluminal vesicle membranes containing ~70% of anionic bis(monoacylglycero)phosphate lipid. Using model bilayer measurements, we show that membrane lipids can have a strong effect on the anthrax toxin channel properties, including the channel-forming activity, voltage-gating, conductance, selectivity, and enzymatic factor binding. Interestingly, the highest PA63 insertion rate was observed in bis(monoacylglycero)phosphate membranes. The molecular dynamics simulation data show that the conformational properties of the channel are different in bis(monoacylglycero)phosphate compared to PC, PE, and PS lipids. The anthrax toxin protein/lipid bilayer system can be advanced as a novel robust model to directly investigate lipid influence on membrane protein properties and protein/protein interactions.
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Affiliation(s)
- Nnanya Kalu
- Department of Biology, The Catholic University of America, 620 Michigan Ave NE, Washington 20064, DC, USA
| | - Yoav Atsmon-Raz
- Department of Biological Sciences, Centre for Molecular Simulation, University of Calgary, 2500 University Drive NW, Calgary T2N 1N4, Alberta, Canada.
| | - Sanaz Momben Abolfath
- Department of Biology, The Catholic University of America, 620 Michigan Ave NE, Washington 20064, DC, USA
| | - Laura Lucas
- Department of Biology, The Catholic University of America, 620 Michigan Ave NE, Washington 20064, DC, USA
| | - Clare Kenney
- Department of Biology, The Catholic University of America, 620 Michigan Ave NE, Washington 20064, DC, USA
| | - Stephen H Leppla
- Microbial Pathogenesis Section, Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 9000 Rockville Pike, Bethesda 20892, MD, USA
| | - D Peter Tieleman
- Department of Biological Sciences, Centre for Molecular Simulation, University of Calgary, 2500 University Drive NW, Calgary T2N 1N4, Alberta, Canada
| | - Ekaterina M Nestorovich
- Department of Biology, The Catholic University of America, 620 Michigan Ave NE, Washington 20064, DC, USA.
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Molecular Identities and ATP Release Activities of Two Types of Volume-Regulatory Anion Channels, VSOR and Maxi-Cl. CURRENT TOPICS IN MEMBRANES 2018; 81:125-176. [PMID: 30243431 DOI: 10.1016/bs.ctm.2018.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
An elaborate volume regulation system based on interplay of ion channels and transporters was evolved to cope with constant osmotic challenges caused by intensive metabolism, transport and other physiological/pathophysiological events. In animal cells, two types of anion channels are directly activated by cell swelling and involved in the regulatory volume decrease (RVD): volume-sensitive outwardly rectifying anion channel (VSOR), also called volume-regulated anion channel (VRAC), and Maxi-Cl which is the most major type of maxi-anion channel (MAC). These two channels have very different biophysical profiles and exhibit opposite dependence on intracellular ATP. After several decades of verifying many false-positive candidates for VSOR and Maxi-Cl, LRRC8 family proteins emerged as major VSOR components, and SLCO2A1 protein as a core of Maxi-Cl. Still, neither of these proteins alone can fully reproduce the native channel phenotypes suggesting existence of missing components. Although both VSOR and Maxi-Cl have pores wide enough to accommodate bulky ATP4- and MgATP2- anions, evidence accumulated hitherto, based on pharmacological and gene silencing experiments, suggests that Maxi-Cl, but not VSOR, serves as one of the major pathways for the release of ATP from swollen and ischemic/hypoxic cells. Relations of VSOR and Maxi-Cl with diseases and their selective pharmacology are the topics promoted by recent advance in molecular identification of the two volume-activated, volume-regulatory anion channels.
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Caterino M, Ruoppolo M, Mandola A, Costanzo M, Orrù S, Imperlini E. Protein-protein interaction networks as a new perspective to evaluate distinct functional roles of voltage-dependent anion channel isoforms. MOLECULAR BIOSYSTEMS 2018; 13:2466-2476. [PMID: 29028058 DOI: 10.1039/c7mb00434f] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Voltage-dependent anion channels (VDACs) are a family of three mitochondrial porins and the most abundant integral membrane proteins of the mitochondrial outer membrane (MOM). VDACs are known to be involved in metabolite/ion transport across the MOM and in many cellular processes ranging from mitochondria-mediated apoptosis to the control of energy metabolism, by interacting with cytosolic, mitochondrial and cytoskeletal proteins and other membrane channels. Despite redundancy and compensatory mechanisms among VDAC isoforms, they display not only different channel properties and protein expression levels, but also distinct protein partners. Here, we review the known protein interactions for each VDAC isoform in order to shed light on their peculiar roles in physiological and pathological conditions. As proteins associated with the MOM, VDAC opening/closure as a metabolic checkpoint is regulated by protein-protein interactions, and is of pharmacological interest in pathological conditions such as cancer. The interactions involving VDAC1 have been characterized more in depth than those involving VDAC2 and VDAC3. Nevertheless, the so far explored VDAC-protein interactions for each isoform show that VDAC1 is mainly involved in the maintenance of cellular homeostasis and in pro-apoptotic processes, whereas VDAC2 displays an anti-apoptotic role. Despite there being limited information on VDAC3, this isoform could contribute to mitochondrial protein quality control and act as a marker of oxidative status. In pathological conditions, namely neurodegenerative and cardiovascular diseases, both VDAC1 and VDAC2 establish abnormal interactions aimed to counteract the mitochondrial dysfunction which contributes to end-organ damage.
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Affiliation(s)
- Marianna Caterino
- Dipartimento di Medicina Molecolare e Biotecnologie Mediche, Università degli Studi di Napoli "Federico II", Naples, Italy
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