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Belosludtsev KN, Ilzorkina AI, Matveeva LA, Chulkov AV, Semenova AA, Dubinin MV, Belosludtseva NV. Effect of VBIT-4 on the functional activity of isolated mitochondria and cell viability. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184329. [PMID: 38679309 DOI: 10.1016/j.bbamem.2024.184329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 04/11/2024] [Accepted: 04/23/2024] [Indexed: 05/01/2024]
Abstract
VBIT-4 is a new inhibitor of the oligomerization of VDAC proteins of the outer mitochondrial membrane preventing the development of oxidative stress, mitochondrial dysfunction, and cell death in various pathologies. However, as a VDAC inhibitor, VBIT-4 may itself cause mitochondrial dysfunction in healthy cells. The article examines the effect of VBIT-4 on the functional activity of rat liver mitochondria and cell cultures. We have demonstrated that high concentrations of VBIT-4 (15-30 μM) suppressed mitochondrial respiration in state 3 and 3UDNP driven by substrates of complex I and II. VBIT-4 induced depolarization of organelles fueled by substrates of complex I but not complex II of the respiratory chain. VBIT-4 has been found to inhibit the activity of complexes I, III, and IV of the respiratory chain. Molecular docking demonstrated that VBIT-4 interacts with the rotenone-binding site in complex I with similar affinity. 15-30 μM VBIT-4 caused an increase in H2O2 production in mitochondria, decreased the Ca2+ retention capacity, but increased the time of Ca2+-dependent mitochondrial swelling. We have found that the incubation of breast adenocarcinoma (MCF-7) with 30 μM VBIT-4 for 48 h led to the decrease of the mitochondrial membrane potential, an increase in ROS production and death of MCF-7 cells. The mechanism of action of VBIT-4 on mitochondria and cells is discussed.
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Affiliation(s)
| | - Anna I Ilzorkina
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow region 142290, Russia
| | | | | | - Alena A Semenova
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia
| | - Mikhail V Dubinin
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia
| | - Natalia V Belosludtseva
- Mari State University, pl. Lenina 1, Yoshkar-Ola, Mari El 424001, Russia; Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Institutskaya 3, Pushchino, Moscow region 142290, Russia
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2
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Belosludtseva NV, Dubinin MV, Belosludtsev KN. Pore-Forming VDAC Proteins of the Outer Mitochondrial Membrane: Regulation and Pathophysiological Role. BIOCHEMISTRY. BIOKHIMIIA 2024; 89:1061-1078. [PMID: 38981701 DOI: 10.1134/s0006297924060075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2024] [Revised: 05/12/2024] [Accepted: 05/27/2024] [Indexed: 07/11/2024]
Abstract
Voltage-dependent anion channels (VDAC1-3) of the outer mitochondrial membrane are a family of pore-forming β-barrel proteins that carry out controlled "filtration" of small molecules and ions between the cytoplasm and mitochondria. Due to the conformational transitions between the closed and open states and interaction with cytoplasmic and mitochondrial proteins, VDACs not only regulate the mitochondrial membrane permeability for major metabolites and ions, but also participate in the control of essential intracellular processes and pathological conditions. This review discusses novel data on the molecular structure, regulatory mechanisms, and pathophysiological role of VDAC proteins, as well as future directions in this area of research.
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Affiliation(s)
- Natalia V Belosludtseva
- Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290, Russia
- Mari State University, Yoshkar-Ola, Mari El, 424001, Russia
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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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Lemeshko VV. VDAC as a voltage-dependent mitochondrial gatekeeper under physiological conditions. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184175. [PMID: 37201560 DOI: 10.1016/j.bbamem.2023.184175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 05/09/2023] [Accepted: 05/11/2023] [Indexed: 05/20/2023]
Abstract
Mitochondria, composed of two membranes, play a key role in energy production in eukaryotic cells. The main function of the inner membrane is oxidative phosphorylation, while the mitochondrial outer membrane (MOM) seems to control the energy flux and exchange of various charged metabolites between mitochondria and the cytosol. Metabolites cross MOM via the various isoforms of voltage-dependent anion channel (VDAC). In turn, VDACs interact with some enzymes, other proteins and molecules, including drugs. This work aimed to analyze various literature experimental data related to targeting mitochondrial VDACs and VDAC-kinase complexes on the basis of the hypothesis of generation of the outer membrane potential (OMP) and OMP-dependent reprogramming of cell energy metabolism. Our previous model of the VDAC-hexokinase-linked generation of OMP was further complemented in this study with an additional regulation of the MOM permeability by the OMP-dependent docking of cytosolic proteins like tubulin to VDACs. Computational analysis of the model suggests that OMP changes might be involved in the mechanisms of apoptosis promotion through the so-called transient hyperpolarization of mitochondria. The high concordance of the performed computational estimations with many published experimental data allows concluding that OMP generation under physiological conditions is highly probable and VDAC might function as an OMP-dependent gatekeeper of mitochondria, controlling cell life and death. The proposed model of OMP generation allows understanding in more detail the mechanisms of cancer death resistance and anticancer action of various drugs and treatments influencing VDAC voltage-gating properties, VDAC content, mitochondrial hexokinase activity and VDAC-kinase interactions in MOM.
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Affiliation(s)
- Victor V Lemeshko
- Universidad Nacional de Colombia, Sede Medellín, Carrera 65, Nro. 59A - 110, Medellín, Colombia.
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5
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Baik SH, Ramanujan VK, Becker C, Fett S, Underhill DM, Wolf AJ. Hexokinase dissociation from mitochondria promotes oligomerization of VDAC that facilitates NLRP3 inflammasome assembly and activation. Sci Immunol 2023; 8:eade7652. [PMID: 37327321 PMCID: PMC10360408 DOI: 10.1126/sciimmunol.ade7652] [Citation(s) in RCA: 32] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 05/25/2023] [Indexed: 06/18/2023]
Abstract
NLRP3 inflammasome activation is a highly regulated process for controlling secretion of the potent inflammatory cytokines IL-1β and IL-18 that are essential during bacterial infection, sterile inflammation, and disease, including colitis, diabetes, Alzheimer's disease, and atherosclerosis. Diverse stimuli activate the NLRP3 inflammasome, and unifying upstream signals has been challenging to identify. Here, we report that a common upstream step in NLRP3 inflammasome activation is the dissociation of the glycolytic enzyme hexokinase 2 from the voltage-dependent anion channel (VDAC) in the outer membrane of mitochondria. Hexokinase 2 dissociation from VDAC triggers activation of inositol triphosphate receptors, leading to release of calcium from the ER, which is taken up by mitochondria. This influx of calcium into mitochondria leads to oligomerization of VDAC, which is known to form a macromolecule-sized pore in the outer membranes of mitochondria that allows proteins and mitochondrial DNA (mtDNA), often associated with apoptosis and inflammation, respectively, to exit the mitochondria. We observe that VDAC oligomers aggregate with NLRP3 during initial assembly of the multiprotein oligomeric NLRP3 inflammasome complex. We also find that mtDNA is necessary for NLRP3 association with VDAC oligomers. These data, together with other recent work, help to paint a more complete picture of the pathway leading to NLRP3 inflammasome activation.
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Affiliation(s)
- Sung Hoon Baik
- F. Widjaja Foundation Inflammatory Bowel & Immunobiology Research Institute, and the Karsh Division of Gastroenterology and Hepatology, Cedars-Sinai Medical Center; Los Angeles, CA, 90048, USA
| | | | - Courtney Becker
- F. Widjaja Foundation Inflammatory Bowel & Immunobiology Research Institute, and the Karsh Division of Gastroenterology and Hepatology, Cedars-Sinai Medical Center; Los Angeles, CA, 90048, USA
| | - Sarah Fett
- F. Widjaja Foundation Inflammatory Bowel & Immunobiology Research Institute, and the Karsh Division of Gastroenterology and Hepatology, Cedars-Sinai Medical Center; Los Angeles, CA, 90048, USA
| | - David M. Underhill
- F. Widjaja Foundation Inflammatory Bowel & Immunobiology Research Institute, and the Karsh Division of Gastroenterology and Hepatology, Cedars-Sinai Medical Center; Los Angeles, CA, 90048, USA
- Department of Biomedical Sciences, Research Division of Immunology, Cedars-Sinai Medical Center; Los Angeles, CA, 90048, USA
| | - Andrea J. Wolf
- F. Widjaja Foundation Inflammatory Bowel & Immunobiology Research Institute, and the Karsh Division of Gastroenterology and Hepatology, Cedars-Sinai Medical Center; Los Angeles, CA, 90048, USA
- Department of Biomedical Sciences, Research Division of Immunology, Cedars-Sinai Medical Center; Los Angeles, CA, 90048, USA
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Tassone A, Meringolo M, Ponterio G, Bonsi P, Schirinzi T, Martella G. Mitochondrial Bioenergy in Neurodegenerative Disease: Huntington and Parkinson. Int J Mol Sci 2023; 24:ijms24087221. [PMID: 37108382 PMCID: PMC10138549 DOI: 10.3390/ijms24087221] [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: 03/27/2023] [Revised: 04/10/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023] Open
Abstract
Strong evidence suggests a correlation between degeneration and mitochondrial deficiency. Typical cases of degeneration can be observed in physiological phenomena (i.e., ageing) as well as in neurological neurodegenerative diseases and cancer. All these pathologies have the dyshomeostasis of mitochondrial bioenergy as a common denominator. Neurodegenerative diseases show bioenergetic imbalances in their pathogenesis or progression. Huntington's chorea and Parkinson's disease are both neurodegenerative diseases, but while Huntington's disease is genetic and progressive with early manifestation and severe penetrance, Parkinson's disease is a pathology with multifactorial aspects. Indeed, there are different types of Parkinson/Parkinsonism. Many forms are early-onset diseases linked to gene mutations, while others could be idiopathic, appear in young adults, or be post-injury senescence conditions. Although Huntington's is defined as a hyperkinetic disorder, Parkinson's is a hypokinetic disorder. However, they both share a lot of similarities, such as neuronal excitability, the loss of striatal function, psychiatric comorbidity, etc. In this review, we will describe the start and development of both diseases in relation to mitochondrial dysfunction. These dysfunctions act on energy metabolism and reduce the vitality of neurons in many different brain areas.
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Affiliation(s)
- Annalisa Tassone
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Maria Meringolo
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
- Saint Camillus International University of Health and Medical Sciences, 00131 Rome, Italy
| | - Giulia Ponterio
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Paola Bonsi
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
| | - Tommaso Schirinzi
- Unit of Neurology, Department of Systems Medicine, Tor Vergata University of Rome, 00133 Rome, Italy
| | - Giuseppina Martella
- Laboratory of Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, 00143 Rome, Italy
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Kmita H, Messina AA, De Pinto V. VDAC as a Cellular Hub: Docking Molecules and Interactions. Int J Mol Sci 2023; 24:ijms24076649. [PMID: 37047622 PMCID: PMC10095168 DOI: 10.3390/ijms24076649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 03/31/2023] [Indexed: 04/05/2023] Open
Abstract
The voltage-dependent anion channel (VDAC) is the primary regulating pathway of water-soluble metabolites and ions across the mitochondrial outer membrane [...]
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Affiliation(s)
- Hanna Kmita
- Department of Bioenergetics, Institute of Molecular Biology and Biotechnology, Faculty of Biology, Adam Mickiewicz University, Uniwersytetu Poznańskiego 6, 61-614 Poznań, Poland
| | - Angela Anna Messina
- Molecular Biology Laboratory, Department of Biological, Geological and Environmental Sciences, University of Catania, Via S. Sofia 64, 95123 Catania, Italy
| | - Vito De Pinto
- Department of Biomedical and Biotechnological Sciences, University of Catania, Via S. Sofia 64, 95123 Catania, Italy
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8
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Lemeshko VV. Apparent "mild depolarization of the inner mitochondrial membrane" as a result of a possible generation of the outer membrane potential. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:184032. [PMID: 35985076 DOI: 10.1016/j.bbamem.2022.184032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/29/2022] [Accepted: 08/08/2022] [Indexed: 12/31/2022]
Abstract
Recently reported kinase-linked mild depolarization of mitochondria, which prevents the generation of the reactive oxygen species (ROS) and disappears in various organs of the old mice, has been assumed to represent a crucial component of the mitochondrial anti-aging program. To measure mitochondrial inner membrane potential (IMP), the authors used fluorescent probe safranin O+. It is widely accepted that the accumulation of such cationic probes in the mitochondrial matrix depends exclusively on IMP, thus completely ignoring the possibility of the outer membrane potential (OMP) generation. However, computational analysis performed in the presented work suggests that the kinase-linked generation of the positive OMP might take place under the described conditions, because the measured potential includes the algebraic sum of both IMP and OMP. Alternatively to the suggested mild depolarization of mitochondria, the reported experimental data might reflect mainly a change of the positive OMP generated by the VDAC-kinase complexes. We also demonstrate that the reported in the literature mitochondrial hyperpolarization induced by erastin (known to prevent VDAC-tubulin interactions) and the depolarization caused by the mitochondrial VDAC knockdowns in the cancer cells might actually represent a decrease or increase, respectively, of the magnitude of the kinase-linked positive OMP. This is consistent with our hypothesis that VDAC voltage gating by the kinase-linked metabolically-dependent OMP plays a very important physiological role in regulating the cell energy metabolism under normal and pathological conditions, in the maintenance of the cell death resistance and even in the genetic aging program.
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Affiliation(s)
- Victor V Lemeshko
- Escuela de Física, Facultad de Ciencias, Universidad Nacional de Colombia, Sede Medellín, Carrera 65, Nro. 59A - 110, Medellín, Colombia.
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9
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Molecular and Cellular Interactions in Pathogenesis of Sporadic Parkinson Disease. Int J Mol Sci 2022; 23:ijms232113043. [PMID: 36361826 PMCID: PMC9657547 DOI: 10.3390/ijms232113043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 10/16/2022] [Accepted: 10/25/2022] [Indexed: 11/23/2022] Open
Abstract
An increasing number of the population all around the world suffer from age-associated neurodegenerative diseases including Parkinson’s disease (PD). This disorder presents different signs of genetic, epigenetic and environmental origin, and molecular, cellular and intracellular dysfunction. At the molecular level, α-synuclein (αSyn) was identified as the principal molecule constituting the Lewy bodies (LB). The gut microbiota participates in the pathogenesis of PD and may contribute to the loss of dopaminergic neurons through mitochondrial dysfunction. The most important pathogenetic link is an imbalance of Ca2+ ions, which is associated with redox imbalance in the cells and increased generation of reactive oxygen species (ROS). In this review, genetic, epigenetic and environmental factors that cause these disorders and their cause-and-effect relationships are considered. As a constituent of environmental factors, the example of organophosphates (OPs) is also reviewed. The role of endothelial damage in the pathogenesis of PD is discussed, and a ‘triple hit hypothesis’ is proposed as a modification of Braak’s dual hit one. In the absence of effective therapies for neurodegenerative diseases, more and more evidence is emerging about the positive impact of nutritional structure and healthy lifestyle on the state of blood vessels and the risk of developing these diseases.
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10
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Dysfunction of Mitochondria in Alzheimer’s Disease: ANT and VDAC Interact with Toxic Proteins and Aid to Determine the Fate of Brain Cells. Int J Mol Sci 2022; 23:ijms23147722. [PMID: 35887070 PMCID: PMC9316216 DOI: 10.3390/ijms23147722] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 07/10/2022] [Accepted: 07/11/2022] [Indexed: 02/05/2023] Open
Abstract
Alzheimer’s disease (AD), certainly the most widespread proteinopathy, has as classical neuropathological hallmarks, two groups of protein aggregates: senile plaques and neurofibrillary tangles. However, the research interest is rapidly gaining ground in a better understanding of other pathological features, first, of all the mitochondrial dysfunctions. Several pieces of evidence support the hypothesis that abnormal mitochondrial function may trigger aberrant processing of amyloid progenitor protein or tau and thus neurodegeneration. Here, our aim is to emphasize the role played by two ‘bioenergetic’ proteins inserted in the mitochondrial membranes, inner and outer, respectively, that is, the adenine nucleotide translocator (ANT) and the voltage-dependent anion channel (VDAC), in the progression of AD. To perform this, we will magnify the ANT and VDAC defects, which are measurable hallmarks of mitochondrial dysfunction, and collect all the existing information on their interaction with toxic Alzheimer’s proteins. The pathological convergence of tau and amyloid β-peptide (Aβ) on mitochondria may finally explain why the therapeutic strategies used against the toxic forms of Aβ or tau have not given promising results separately. Furthermore, the crucial role of ANT-1 and VDAC impairment in the onset/progression of AD opens a window for new therapeutic strategies aimed at preserving/improving mitochondrial function, which is suspected to be the driving force leading to plaque and tangle deposition in AD.
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11
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De Pinto V, Mahalakshmi R, Messina A. Editorial: VDAC Structure and Function: An Up-to-Date View. Front Physiol 2022; 13:871586. [PMID: 35480047 PMCID: PMC9037234 DOI: 10.3389/fphys.2022.871586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 03/08/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Vito De Pinto
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy.,INBB-Biostructures and Biosystems National Institute, Rome, Italy
| | | | - Angela Messina
- Department of Biological, Geological and Environmental Sciences, University of Catania, Catania, Italy
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12
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Karachitos A, Grabiński W, Baranek M, Kmita H. Redox-Sensitive VDAC: A Possible Function as an Environmental Stress Sensor Revealed by Bioinformatic Analysis. Front Physiol 2021; 12:750627. [PMID: 34966287 PMCID: PMC8710658 DOI: 10.3389/fphys.2021.750627] [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: 07/30/2021] [Accepted: 11/12/2021] [Indexed: 11/13/2022] Open
Abstract
Voltage-dependent anion-selective channel (VDAC) allows the exchange of small metabolites and inorganic ions across the mitochondrial outer membrane. It is involved in complex interactions that regulate mitochondrial and cellular functioning. Many organisms have several VDAC paralogs that play distinct but poorly understood roles in the life and death of cells. It is assumed that such a large diversity of VDAC-encoding genes might cause physiological plasticity to cope with abiotic and biotic stresses known to impact mitochondrial function. Moreover, cysteine residues in mammalian VDAC paralogs may contribute to the reduction-oxidation (redox) sensor function based on disulfide bond formation and elimination, resulting in redox-sensitive VDAC (rsVDAC). Therefore, we analyzed whether rsVDAC is possible when only one VDAC variant is present in mitochondria and whether all VDAC paralogs present in mitochondria could be rsVDAC, using representatives of currently available VDAC amino acid sequences. The obtained results indicate that rsVDAC can occur when only one VDAC variant is present in mitochondria; however, the possibility of all VDAC paralogs in mitochondria being rsVDAC is very low. Moreover, the presence of rsVDAC may correlate with habitat conditions as rsVDAC appears to be prevalent in parasites. Thus, the channel may mediate detection and adaptation to environmental conditions.
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Affiliation(s)
- Andonis Karachitos
- Department of Bioenergetics, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznań, Poland
| | - Wojciech Grabiński
- Department of Bioenergetics, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznań, Poland
| | - Martyna Baranek
- Department of Bioenergetics, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznań, Poland
| | - Hanna Kmita
- Department of Bioenergetics, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Poznań, Poland
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13
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Hoogerheide DP, Gurnev PA, Rostovtseva TK, Bezrukov SM. Voltage-activated complexation of α-synuclein with three diverse β-barrel channels: VDAC, MspA, and α-hemolysin. Proteomics 2021; 22:e2100060. [PMID: 34813679 DOI: 10.1002/pmic.202100060] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 01/07/2023]
Abstract
Voltage-activated complexation is the process by which a transmembrane potential drives complex formation between a membrane-embedded channel and a soluble or membrane-peripheral target protein. Metabolite and calcium flux across the mitochondrial outer membrane was shown to be regulated by voltage-activated complexation of the voltage-dependent anion channel (VDAC) and either dimeric tubulin or α-synuclein (αSyn). However, the roles played by VDAC's characteristic attributes-its anion selectivity and voltage gating behavior-have remained unclear. Here, we compare in vitro measurements of voltage-activated complexation of αSyn with three well-characterized β-barrel channels-VDAC, MspA, and α-hemolysin-that differ widely in their organism of origin, structure, geometry, charge density distribution, and voltage gating behavior. The voltage dependences of the complexation dynamics for the different channels are observed to differ quantitatively but have similar qualitative features. In each case, energy landscape modeling describes the complexation dynamics in a manner consistent with the known properties of the individual channels, while voltage gating does not appear to play a role. The reaction free energy landscapes thus calculated reveal a non-trivial dependence of the αSyn/channel complex stability on the surface density of αSyn.
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Affiliation(s)
- David P Hoogerheide
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, USA
| | - Philip A Gurnev
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Tatiana K Rostovtseva
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Sergey M Bezrukov
- Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
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