1
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Su Z, Zhang G, Li X, Zhang H. Inverse correlation between Alzheimer's disease and cancer from the perspective of hypoxia. Neurobiol Aging 2023; 131:59-73. [PMID: 37572528 DOI: 10.1016/j.neurobiolaging.2023.07.002] [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: 01/08/2023] [Revised: 06/02/2023] [Accepted: 07/03/2023] [Indexed: 08/14/2023]
Abstract
Sporadic Alzheimer's disease and cancer remain epidemiologically inversely related, and exploring the reverse pathogenesis is important for our understanding of both. Cognitive dysfunctions in Alzheimer's disease (AD) might result from the depletion of adaptive reserves in the brain. Energy storage in the brain is limited and is dynamically regulated by neurovascular and neurometabolic coupling. The research on neurodegenerative diseases has been dominated by the neurocentric view that neuronal defects cause the diseases. However, the proposal of the 2-hit vascular hypothesis in AD led us to focus on alterations in the vasculature, especially hypoperfusion. Chronic hypoxia is a feature shared by AD and cancer. It is interesting how contradicting chronic hypoxia's effects on both cancer and AD are. In this article, we discuss the potential links between the 2 diseases' etiology, from comparable upstream circumstances to diametrically opposed downstream effects. We suggest opposing potential mechanisms, including upregulation and downregulation of hypoxia-inducible factor-1α, the Warburg and reverse-Warburg effects, lactate-mediated intracellular acidic and alkaline conditions, and VDAC1-mediated apoptosis and antiapoptosis, and search for regulators that may be identified as the crossroads between cancer and AD.
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Affiliation(s)
- Zhan Su
- Department of Neurology and Neuroscience Centre, The First Hospital of Jilin University, Changchun, China
| | - Guimei Zhang
- Department of Neurology and Neuroscience Centre, The First Hospital of Jilin University, Changchun, China
| | - Xiangting Li
- Department of Neurology and Neuroscience Centre, The First Hospital of Jilin University, Changchun, China
| | - Haining Zhang
- Department of Neurology and Neuroscience Centre, The First Hospital of Jilin University, Changchun, China.
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2
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Ventura C, Junco M, Santiago Valtierra FX, Gooz M, Zhiwei Y, Townsend DM, Woster PM, Maldonado EN. Synergism of small molecules targeting VDAC with sorafenib, regorafenib or lenvatinib on hepatocarcinoma cell proliferation and survival. Eur J Pharmacol 2023; 957:176034. [PMID: 37652292 PMCID: PMC10586475 DOI: 10.1016/j.ejphar.2023.176034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 08/25/2023] [Accepted: 08/28/2023] [Indexed: 09/02/2023]
Abstract
Voltage dependent anion channels (VDAC) in the outer mitochondrial membrane regulate the influx of metabolites that sustain mitochondrial metabolism and the efflux of ATP to the cytosol. Free tubulin and NADH close VDAC. The VDAC-binding small molecules X1 and SC18 modulate mitochondrial metabolism. X1 antagonizes the inhibitory effect of tubulin on VDAC. SC18 occupies an NADH-binding pocket in the inner wall of all VDAC isoforms. Here, we hypothesized that X1 and SC18 have a synergistic effect with sorafenib, regorafenib or lenvatinib to arrest proliferation and induce death in hepatocarcinoma cells. We used colony formation assays to determine cell proliferation, and a combination of calcein/propidium iodide, and trypan blue exclusion to assess cell death in the well differentiated Huh7 and the poorly differentiated SNU-449 cells. Synergism was assessed using the Chou-Talalay method. The inhibitory effect of X1, SC18, sorafenib, regorafenib and lenvatinib was concentration and time dependent. IC50s calculated from the inhibition of clonogenic capacity were lower than those determined from cell survival. At IC50s that inhibited cell proliferation, SC18 arrested cells in G0/G1. SC18 at 0.25-2 IC50s had a synergistic effect with sorafenib on clonogenic inhibition in Huh7 and SNU-449 cells, and with regorafenib or lenvatinib in SNU-449 cells. X1 or SC18 also had synergistic effects with sorafenib on promoting cell death at 0.5-2 IC50s for SC18 in Huh7 and SNU-449 cells. These results suggest that small molecules targeting VDAC represent a potential new class of drugs to treat liver cancer.
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Affiliation(s)
- C Ventura
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA; Institute for Immunological and Physiopathological Studies (IIFP), National Scientific and Technical Research Council (CONICET), Argentina
| | - M Junco
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - F X Santiago Valtierra
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - M Gooz
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - Y Zhiwei
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - D M Townsend
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - P M Woster
- Department of Drug Discovery & Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA
| | - E 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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3
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Bora JR, Mahalakshmi R. Photoradical-Mediated Catalyst-Independent Protein Cross-Link with Unusual Fluorescence Properties. Chembiochem 2023; 24:e202300380. [PMID: 37232210 PMCID: PMC7615464 DOI: 10.1002/cbic.202300380] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 05/25/2023] [Accepted: 05/26/2023] [Indexed: 05/27/2023]
Abstract
Photo-actively modified natural amino acids have served as lucrative probes for precise mapping of the dynamics, interaction networks, and turnover of cytosolic proteins both in vivo and ex vivo. In our attempts to extend the utility of photoreactive reporters to map the molecular characteristics of vital membrane proteins, we carried out site-selective incorporation of 7-fluoro-indole in the human mitochondrial outer membrane protein VDAC2 (voltage-dependent anion channel isoform 2), with the aim of generating Trp-Phe/Tyr cross-links. Prolonged irradiation at 282 nm provided us with a surprisingly unusual fluorophore that displayed sizably red-shifted excitation (λex-max =280 nm→360 nm) and emission (λem-max =330 nm→430 nm) spectra that was reversible with organic solvents. By measuring the kinetics of the photo-activated cross-linking with a library of hVDAC2 variants, we demonstrate that formation of this unusual fluorophore is kinetically retarded, independent of tryptophan, and is site-specific. Using other membrane (Tom40 and Sam50) and cytosolic (MscR and DNA Pol I) proteins, we additionally show that formation of this fluorophore is protein-independent. Our findings reveal the photoradical-mediated accumulation of reversible tyrosine cross-links, with unusual fluorescent properties. Our findings have immediate applications in protein biochemistry and UV-mediated protein aggregation and cellular damage, opening avenues for formulating therapeutics that prolong cell viability in humans.
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Affiliation(s)
- Jinam Ravindra Bora
- Molecular Biophysics Laboratory Department of Biological Sciences Indian Institute of Science Education and Research Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh (India)
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory Department of Biological Sciences Indian Institute of Science Education and Research Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh (India)
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4
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Ikunishi R, Otani R, Masuya T, Shinzawa-Itoh K, Shiba T, Murai M, Miyoshi H. Respiratory complex I in mitochondrial membrane catalyzes oversized ubiquinones. J Biol Chem 2023; 299:105001. [PMID: 37394006 PMCID: PMC10416054 DOI: 10.1016/j.jbc.2023.105001] [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: 05/08/2023] [Revised: 06/20/2023] [Accepted: 06/23/2023] [Indexed: 07/04/2023] Open
Abstract
NADH-ubiquinone (UQ) oxidoreductase (complex I) couples electron transfer from NADH to UQ with proton translocation in its membrane part. The UQ reduction step is key to triggering proton translocation. Structural studies have identified a long, narrow, tunnel-like cavity within complex I, through which UQ may access a deep reaction site. To elucidate the physiological relevance of this UQ-accessing tunnel, we previously investigated whether a series of oversized UQs (OS-UQs), whose tail moiety is too large to enter and transit the narrow tunnel, can be catalytically reduced by complex I using the native enzyme in bovine heart submitochondrial particles (SMPs) and the isolated enzyme reconstituted into liposomes. Nevertheless, the physiological relevance remained unclear because some amphiphilic OS-UQs were reduced in SMPs but not in proteoliposomes, and investigation of extremely hydrophobic OS-UQs was not possible in SMPs. To uniformly assess the electron transfer activities of all OS-UQs with the native complex I, here we present a new assay system using SMPs, which were fused with liposomes incorporating OS-UQ and supplemented with a parasitic quinol oxidase to recycle reduced OS-UQ. In this system, all OS-UQs tested were reduced by the native enzyme, and the reduction was coupled with proton translocation. This finding does not support the canonical tunnel model. We propose that the UQ reaction cavity is flexibly open in the native enzyme to allow OS-UQs to access the reaction site, but their access is obstructed in the isolated enzyme as the cavity is altered by detergent-solubilizing from the mitochondrial membrane.
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Affiliation(s)
- Ryo Ikunishi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Ryohei Otani
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Takahiro Masuya
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Kyoko Shinzawa-Itoh
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Hyogo, Japan
| | - Tomoo Shiba
- Department of Applied Biology, Graduate School of Science and Technology, Kyoto Institute of Technology, Kyoto, Japan
| | - Masatoshi Murai
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Hideto Miyoshi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
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5
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Mayse LA, Movileanu L. Gating of β-Barrel Protein Pores, Porins, and Channels: An Old Problem with New Facets. Int J Mol Sci 2023; 24:12095. [PMID: 37569469 PMCID: PMC10418385 DOI: 10.3390/ijms241512095] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 07/23/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
β barrels are ubiquitous proteins in the outer membranes of mitochondria, chloroplasts, and Gram-negative bacteria. These transmembrane proteins (TMPs) execute a wide variety of tasks. For example, they can serve as transporters, receptors, membrane-bound enzymes, as well as adhesion, structural, and signaling elements. In addition, multimeric β barrels are common structural scaffolds among many pore-forming toxins. Significant progress has been made in understanding the functional, structural, biochemical, and biophysical features of these robust and versatile proteins. One frequently encountered fundamental trait of all β barrels is their voltage-dependent gating. This process consists of reversible or permanent conformational transitions between a large-conductance, highly permeable open state and a low-conductance, solute-restrictive closed state. Several intrinsic molecular mechanisms and environmental factors modulate this universal property of β barrels. This review article outlines the typical signatures of voltage-dependent gating. Moreover, we discuss recent developments leading to a better qualitative understanding of the closure dynamics of these TMPs.
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Affiliation(s)
- Lauren A. Mayse
- Department of Physics, Syracuse University, 201 Physics Building, Syracuse, NY 13244, USA;
- Department of Biomedical and Chemical Engineering, Syracuse University, 223 Link Hall, Syracuse, NY 13244, USA
| | - Liviu Movileanu
- Department of Physics, Syracuse University, 201 Physics Building, Syracuse, NY 13244, USA;
- Department of Biomedical and Chemical Engineering, Syracuse University, 223 Link Hall, Syracuse, NY 13244, USA
- The BioInspired Institute, Syracuse University, Syracuse, NY 13244, USA
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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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Yokoyama M, Fujita T, Kadonosawa Y, Tatara Y, Motooka D, Ikawa M, Fujii H, Yokoayama Y. Development of transgenic mice overexpressing mouse carbonyl reductase 1. Mol Biol Rep 2023; 50:531-540. [PMID: 36352178 DOI: 10.1007/s11033-022-07994-x] [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: 05/06/2022] [Accepted: 09/29/2022] [Indexed: 11/10/2022]
Abstract
BACKGROUND Carbonyl reductase 1 (CBR1) is a nicotinamide adenine dinucleotide phosphate (NADPH)-dependent reductase with broad substrate specificity. CBR1 catalyzes the reduction of numerous carbonyl compounds, including quinones, prostaglandins, menadione, and multiple xenobiotics, while also participating in various cellular processes, such as carcinogenesis, apoptosis, signal transduction, and drug resistance. In this study, we aimed to generate transgenic mice overexpressing mouse Cbr1 (mCbr1), characterize the mCbr1 expression in different organs, and identify changes in protein expression patterns. METHODS AND RESULTS To facilitate a deeper understanding of the functions of CBR1, we generated transgenic mice overexpressing CBR1 throughout the body. These transgenic mice overexpress 3xFLAG-tagged mCbr1 (3xFLAG-mCbr1) under the CAG promoter. Two lines of transgenic mice were generated, one with 3xFLAG-mCbr1 expression in multiple tissues, and the other, with specific expression of 3xFLAG-mCbr1 in the heart. Pathway and network analysis using transgenic mouse hearts identified 73 proteins with levels of expression correlating with mCbr1 overexpression. The expression of voltage-gated anion channels, which may be directly related to calcium ion-related myocardial contraction, was also upregulated. CONCLUSION mCbr1 transgenic mice may be useful for further in vivo analyses of the molecular mechanisms regulated by Cbr1; such analyses will provide a better understanding of its effects on carcinogenesis and cardiotoxicity of certain cancer drugs.
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Affiliation(s)
- Minako Yokoyama
- Department of Obstetrics and Gynecology, Graduate School of Medicine, Hirosaki University, 5 Zaifu-cho, 036-8562, Hirosaki, Aomori, Japan
| | - Toshitsugu Fujita
- Department of Biochemistry and Genome Biology, Graduate School of Medicine, Hirosaki University, 5 Zaifu-cho, 036-8562, Hirosaki, Aomori, Japan
| | - Yuka Kadonosawa
- Department of Obstetrics and Gynecology, Graduate School of Medicine, Hirosaki University, 5 Zaifu-cho, 036-8562, Hirosaki, Aomori, Japan
| | - Yota Tatara
- Department of Stress Response Science, Center for Advanced Medical Research, Graduate School of Medicine, Hirosaki University, 5 Zaifu-cho, 036-8562, Hirosaki, Aomori, Japan
| | - Daisuke Motooka
- Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, 565-0871, Suita, Osaka, Japan
| | - Masahito Ikawa
- Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, 565-0871, Suita, Osaka, Japan
| | - Hodaka Fujii
- Department of Biochemistry and Genome Biology, Graduate School of Medicine, Hirosaki University, 5 Zaifu-cho, 036-8562, Hirosaki, Aomori, Japan
| | - Yoshihito Yokoayama
- Department of Obstetrics and Gynecology, Graduate School of Medicine, Hirosaki University, 5 Zaifu-cho, 036-8562, Hirosaki, Aomori, Japan.
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8
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Hu H, Guo L, Overholser J, Wang X. Mitochondrial VDAC1: A Potential Therapeutic Target of Inflammation-Related Diseases and Clinical Opportunities. Cells 2022; 11:cells11193174. [PMID: 36231136 PMCID: PMC9562648 DOI: 10.3390/cells11193174] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 09/27/2022] [Accepted: 09/30/2022] [Indexed: 12/03/2022] Open
Abstract
The multifunctional protein, voltage-dependent anion channel 1 (VDAC1), is located on the mitochondrial outer membrane. It is a pivotal protein that maintains mitochondrial function to power cellular bioactivities via energy generation. VDAC1 is involved in regulating energy production, mitochondrial oxidase stress, Ca2+ transportation, substance metabolism, apoptosis, mitochondrial autophagy (mitophagy), and many other functions. VDAC1 malfunction is associated with mitochondrial disorders that affect inflammatory responses, resulting in an up-regulation of the body’s defensive response to stress stimulation. Overresponses to inflammation may cause chronic diseases. Mitochondrial DNA (mtDNA) acts as a danger signal that can further trigger native immune system activities after its secretion. VDAC1 mediates the release of mtDNA into the cytoplasm to enhance cytokine levels by activating immune responses. VDAC1 regulates mitochondrial Ca2+ transportation, lipid metabolism and mitophagy, which are involved in inflammation-related disease pathogenesis. Many scientists have suggested approaches to deal with inflammation overresponse issues via specific targeting therapies. Due to the broad functionality of VDAC1, it may become a useful target for therapy in inflammation-related diseases. The mechanisms of VDAC1 and its role in inflammation require further exploration. We comprehensively and systematically summarized the role of VDAC1 in the inflammatory response, and hope that our research will lead to novel therapeutic strategies that target VDAC1 in order to treat inflammation-related disorders.
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Affiliation(s)
- Hang Hu
- Inflammation & Allergic Diseases Research Unit, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, China
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, China
| | - Linlin Guo
- Department of Obstetrics and Gynecology, The Ohio State University Wexner Medical Center at The Ohio State University, Columbus, OH 43210, USA
- Correspondence: (L.G.); (X.W.)
| | - Jay Overholser
- Department of Obstetrics and Gynecology, The Ohio State University Wexner Medical Center at The Ohio State University, Columbus, OH 43210, USA
| | - Xing Wang
- Inflammation & Allergic Diseases Research Unit, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, China
- Department of Respiratory and Critical Care Medicine, The Affiliated Hospital of Southwest Medical University, Luzhou 646000, China
- Correspondence: (L.G.); (X.W.)
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9
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Shi W, Hu R, Zhao R, Zhu J, Shen H, Li H, Wang L, Yang Z, Jiang Q, Qiao Y, Jiang G, Cheng J, Wan X. Transcriptome analysis of hepatopancreas and gills of Palaemon gravieri under salinity stress. Gene 2022; 851:147013. [DOI: 10.1016/j.gene.2022.147013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 09/01/2022] [Accepted: 10/25/2022] [Indexed: 11/04/2022]
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10
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Mitochondrial Porin Is Involved in Development, Virulence, and Autophagy in Fusarium graminearum. J Fungi (Basel) 2022; 8:jof8090936. [PMID: 36135661 PMCID: PMC9506537 DOI: 10.3390/jof8090936] [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: 08/11/2022] [Revised: 08/28/2022] [Accepted: 09/02/2022] [Indexed: 11/22/2022] Open
Abstract
Mitochondrial porin, the voltage-dependent anion-selective channel (VDAC), is the most abundant protein in the outer membrane, and is critical for the exchange of metabolites and phospholipids in yeast and mammals. However, the functions of porin in phytopathogenic fungi are not known. In this study, we characterized a yeast porin orthologue, Fgporin, in Fusarium graminearum. The deletion of Fgporin resulted in defects in hyphal growth, conidiation, and perithecia development. The Fgporin deletion mutant showed reduced virulence, deoxynivalenol production, and lipid droplet accumulation. In addition, the Fgporin deletion mutant exhibited morphological changes and the dysfunction of mitochondria, and also displayed impaired autophagy in the non-nitrogen medium compared to the wild type. Yeast two-hybrid and bimolecular fluorescence complementation assays indicated that Fgporin interacted with FgUps1/2, but not with FgMdm35. Taken together, these results suggest that Fgporin is involved in hyphal growth, asexual and sexual reproduction, virulence, and autophagy in F. graminearum.
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11
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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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12
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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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13
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Uno S, Masuya T, Zdorevskyi O, Ikunishi R, Shinzawa-Itoh K, Lasham J, Sharma V, Murai M, Miyoshi H. Diverse reaction behaviors of artificial ubiquinones in mitochondrial respiratory complex I. J Biol Chem 2022; 298:102075. [PMID: 35643318 PMCID: PMC9243180 DOI: 10.1016/j.jbc.2022.102075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 05/23/2022] [Accepted: 05/23/2022] [Indexed: 11/24/2022] Open
Abstract
The ubiquinone (UQ) reduction step catalyzed by NADH-UQ oxidoreductase (mitochondrial respiratory complex I) is key to triggering proton translocation across the inner mitochondrial membrane. Structural studies have identified a long, narrow, UQ-accessing tunnel within the enzyme. We previously demonstrated that synthetic oversized UQs, which are unlikely to transit this narrow tunnel, are catalytically reduced by native complex I embedded in submitochondrial particles but not by the isolated enzyme. To explain this contradiction, we hypothesized that access of oversized UQs to the reaction site is obstructed in the isolated enzyme because their access route is altered following detergent solubilization from the inner mitochondrial membrane. In the present study, we investigated this using two pairs of photoreactive UQs (pUQm-1/pUQp-1 and pUQm-2/pUQp-2), with each pair having the same chemical properties except for a ∼1.0 Å difference in side-chain widths. Despite this subtle difference, reduction of the wider pUQs by the isolated complex was significantly slower than of the narrower pUQs, but both were similarly reduced by the native enzyme. In addition, photoaffinity-labeling experiments using the four [125I]pUQs demonstrated that their side chains predominantly label the ND1 subunit with both enzymes but at different regions around the tunnel. Finally, we show that the suppressive effects of different types of inhibitors on the labeling significantly changed depending on [125I]pUQs used, indicating that [125I]pUQs and these inhibitors do not necessarily share a common binding cavity. Altogether, we conclude that the reaction behaviors of pUQs cannot be simply explained by the canonical UQ tunnel model.
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Affiliation(s)
- Shinpei Uno
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Takahiro Masuya
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | | | - Ryo Ikunishi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Kyoko Shinzawa-Itoh
- Department of Life Science, Graduate School of Life Science, University of Hyogo, Hyogo, Japan
| | - Jonathan Lasham
- Department of Physics, University of Helsinki, Helsinki, Finland
| | - Vivek Sharma
- Department of Physics, University of Helsinki, Helsinki, Finland; Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Masatoshi Murai
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan
| | - Hideto Miyoshi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
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14
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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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15
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Yoshinaga N, Numata K. Rational Designs at the Forefront of Mitochondria-Targeted Gene Delivery: Recent Progress and Future Perspectives. ACS Biomater Sci Eng 2022; 8:348-359. [PMID: 34979085 DOI: 10.1021/acsbiomaterials.1c01114] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Mitochondria play an essential role in cellular metabolism and generate energy in cells. To support these functions, several proteins are encoded in the mitochondrial DNA (mtDNA). The mutation of mtDNA causes mitochondrial dysfunction and ultimately results in a variety of inherited diseases. To date, gene delivery systems targeting mitochondria have been developed to ameliorate mtDNA mutations. However, applications of these strategies in mitochondrial gene therapy are still being explored and optimized. Thus, from this perspective, we herein highlight recent mitochondria-targeting strategies for gene therapy and discuss future directions for effective mitochondria-targeted gene delivery.
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Affiliation(s)
- Naoto Yoshinaga
- Biomacromolecule Research Team, RIKEN Center for Sustainable Resource Science, Saitama 351-0198, Japan
| | - Keiji Numata
- Biomacromolecule Research Team, RIKEN Center for Sustainable Resource Science, Saitama 351-0198, Japan.,Department of Material Chemistry, Kyoto University, Kyoto 606-8501, Japan
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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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Enhancing the Cell-Free Expression of Native Membrane Proteins by In Silico Optimization of the Coding Sequence-An Experimental Study of the Human Voltage-Dependent Anion Channel. MEMBRANES 2021; 11:membranes11100741. [PMID: 34677509 PMCID: PMC8540592 DOI: 10.3390/membranes11100741] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 09/12/2021] [Accepted: 09/13/2021] [Indexed: 11/16/2022]
Abstract
Membrane proteins are involved in many aspects of cellular biology; for example, they regulate how cells interact with their environment, so such proteins are important drug targets. The rapid advancement in the field of immune effector cell therapy has been expanding the horizons of synthetic membrane receptors in the areas of cell-based immunotherapy and cellular medicine. However, the investigation of membrane proteins, which are key constituents of cells, is hampered by the difficulty and complexity of their in vitro synthesis, which is of unpredictable yield. Cell-free synthesis is herein employed to unravel the impact of the expression construct on gene transcription and translation, without the complex regulatory mechanisms of cellular systems. Through the systematic design of plasmids in the immediacy of the start of the target gene, it was possible to identify translation initiation and the conformation of mRNA as the main factors governing the cell-free expression efficiency of the human voltage-dependent anion channel (VDAC), which is a relevant membrane protein in drug-based therapy. A simple translation initiation model was developed to quantitatively assess the expression potential for the designed constructs. A scoring function that quantifies the feasibility of the formation of the translation initiation complex through the ribosome–mRNA hybridization energy and the accessibility of the mRNA segment binding to the ribosome is proposed. The scoring function enables one to optimize plasmid sequences and semi-quantitatively predict protein expression efficiencies. This scoring function is publicly available as webservice XenoExpressO at University of Vienna, Austria.
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19
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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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20
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Suthar SK, Alam MM, Lee J, Monga J, Joseph A, Lee SY. Bioinformatic Analyses of Canonical Pathways of TSPOAP1 and its Roles in Human Diseases. Front Mol Biosci 2021; 8:667947. [PMID: 34212002 PMCID: PMC8239723 DOI: 10.3389/fmolb.2021.667947] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 05/21/2021] [Indexed: 12/19/2022] Open
Abstract
TSPO-associated protein 1 (TSPOAP1) is a cytoplasmic protein and is closely associated with its mitochondrial transmembrane protein partner translocator protein (TSPO). To decipher the canonical signalling pathways of TSPOAP1, its role in human diseases and disorders, and relationship with TSPO; expression analyses of TSPOAP1- and TSPO-associated human genes were performed by Qiagen Ingenuity Pathway Analysis (IPA). In the expression analysis, necroptosis and sirtuin signalling pathways, mitochondrial dysfunction, and inflammasome were the top canonical pathways for both TSPOAP1 and TSPO, confirming the close relationship between these two proteins. A distribution analysis of common proteins in all the canonical pathways predicted for TSPOAP1 revealed that tumor necrosis factor receptor 1 (TNFR1), vascular cell adhesion molecule 1 (VCAM1), cyclic AMP response element-binding protein 1 (CREB1), T-cell receptor (TCR), nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain containing 3 (NLRP3), DNA-dependent protein kinase (DNA-PK or PRKDC), and mitochondrial permeability transition pore (mPTP) were the major interaction partners of TSPOAP1, highlighting the role of TSPOAP1 in inflammation, particularly neuroinflammation. An analysis of the overlap between TSPO and TSPOAP1 Homo sapiens genes and top-ranked canonical pathways indicated that TSPO and TSPOAP1 interact via voltage-dependent anion-selective channels (VDAC1/2/3). A heat map analysis indicated that TSPOAP1 has critical roles in inflammatory, neuroinflammatory, psychiatric, and metabolic diseases and disorders, and cancer. Taken together, this information improves our understanding of the mechanism of action and biological functions of TSPOAP1 as well as its relationship with TSPO; furthermore, these results could provide new directions for in-depth functional studies of TSPOAP1 aimed at unmasking its detailed functions.
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Affiliation(s)
- Sharad Kumar Suthar
- Neuroscience Research Institute, Gachon University, Incheon, South Korea.,Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, India
| | | | - Jihye Lee
- Neuroscience Research Institute, Gachon University, Incheon, South Korea
| | - Jitender Monga
- Department of Urology, Postgraduate Institute of Medical Education and Research, Chandigarh, India
| | - Alex Joseph
- Manipal College of Pharmaceutical Sciences, Manipal University, Manipal, India
| | - Sang-Yoon Lee
- Neuroscience Research Institute, Gachon University, Incheon, South Korea.,Department of Neuroscience, College of Medicine, Gachon University, Incheon, South Korea
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21
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Di Rosa MC, Guarino F, Conti Nibali S, Magrì A, De Pinto V. Voltage-Dependent Anion Selective Channel Isoforms in Yeast: Expression, Structure, and Functions. Front Physiol 2021; 12:675708. [PMID: 34093236 PMCID: PMC8171188 DOI: 10.3389/fphys.2021.675708] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/20/2021] [Indexed: 12/25/2022] Open
Abstract
Mitochondrial porins, also known as voltage-dependent anion selective channels (VDACs), are pore-forming molecules of the outer mitochondrial membranes, involved in the regulation of metabolic flux between cytosol and mitochondria. Playing such an essential role, VDAC proteins are evolutionary conserved and isoforms are present in numerous species. The quest for specific function(s) related to the raise of multiple isoforms is an intriguing theme. The yeast Saccharomyces cerevisiae genome is endowed with two different VDAC genes encoding for two distinct porin isoforms, definitely less characterized in comparison to mammalian counterpart. While yVDAC1 has been extensively studied, the second isoform, yVDAC2, is much less expressed, and has a still misunderstood function. This review will recapitulate the known and poorly known information in the literature, in the light of the growing interest about the features of VDAC isoforms in the cell.
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Affiliation(s)
- Maria Carmela Di Rosa
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Francesca Guarino
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy.,we.MitoBiotech S.R.L., Catania, Italy
| | - Stefano Conti Nibali
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Andrea Magrì
- we.MitoBiotech S.R.L., Catania, Italy.,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.,we.MitoBiotech S.R.L., Catania, Italy
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22
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Coleman PS, Parlo RA. Warburg's Ghost-Cancer's Self-Sustaining Phenotype: The Aberrant Carbon Flux in Cholesterol-Enriched Tumor Mitochondria via Deregulated Cholesterogenesis. Front Cell Dev Biol 2021; 9:626316. [PMID: 33777935 PMCID: PMC7994618 DOI: 10.3389/fcell.2021.626316] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 01/29/2021] [Indexed: 01/08/2023] Open
Abstract
Interpreting connections between the multiple networks of cell metabolism is indispensable for understanding how cells maintain homeostasis or transform into the decontrolled proliferation phenotype of cancer. Situated at a critical metabolic intersection, citrate, derived via glycolysis, serves as either a combustible fuel for aerobic mitochondrial bioenergetics or as a continuously replenished cytosolic carbon source for lipid biosynthesis, an essentially anaerobic process. Therein lies the paradox: under what conditions do cells control the metabolic route by which they process citrate? The Warburg effect exposes essentially the same dilemma—why do cancer cells, despite an abundance of oxygen needed for energy-generating mitochondrial respiration with citrate as fuel, avoid catabolizing mitochondrial citrate and instead rely upon accelerated glycolysis to support their energy requirements? This review details the genesis and consequences of the metabolic paradigm of a “truncated” Krebs/TCA cycle. Abundant data are presented for substrate utilization and membrane cholesterol enrichment in tumors that are consistent with criteria of the Warburg effect. From healthy cellular homeostasis to the uncontrolled proliferation of tumors, metabolic alterations center upon the loss of regulation of the cholesterol biosynthetic pathway. Deregulated tumor cholesterogenesis at the HMGR locus, generating enhanced carbon flux through the cholesterol synthesis pathway, is an absolute prerequisite for DNA synthesis and cell division. Therefore, expedited citrate efflux from cholesterol-enriched tumor mitochondria via the CTP/SLC25A1 citrate transporter is fundamental for sustaining the constant demand for cytosolic citrate that fuels the elevated flow of carbons from acetyl-CoA through the deregulated pathway of cholesterol biosynthesis.
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Affiliation(s)
| | - Risa A Parlo
- Kingsborough Community College, Brooklyn, NY, United States
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23
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Skvortsov AT, Dagdug L, Berezhkovskii AM, MacGillivray IR, Bezrukov SM. Evaluating diffusion resistance of a constriction in a membrane channel by the method of boundary homogenization. Phys Rev E 2021; 103:012408. [PMID: 33601596 DOI: 10.1103/physreve.103.012408] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 12/18/2020] [Indexed: 11/07/2022]
Abstract
In this paper we analyze diffusive transport of noninteracting electrically uncharged solute molecules through a cylindrical membrane channel with a constriction located in the middle of the channel. The constriction is modeled by an infinitely thin partition with a circular hole in its center. The focus is on how the presence of the partition slows down the transport governed by the difference in the solute concentrations in the two reservoirs separated by the membrane. It is assumed that the solutions in both reservoirs are well stirred. To quantify the effect of the constriction we use the notion of diffusion resistance defined as the ratio of the concentration difference to the steady-state flux. We show that when the channel length exceeds its radius, the diffusion resistance is the sum of the diffusion resistance of the cylindrical channel without a partition and an additional diffusion resistance due to the presence of the partition. We derive an expression for the additional diffusion resistance as a function of the tube radius and that of the hole in the partition. The derivation involves the replacement of the nonpermeable partition with the hole by an effective uniform semipermeable partition with a properly chosen permeability. Such a replacement makes it possible to reduce the initial three-dimensional diffusion problem to a one-dimensional one that can be easily solved. To determine the permeability of the effective partition, we take advantage of the results found earlier for trapping of diffusing particles by inhomogeneous surfaces, which were obtained with the method of boundary homogenization. Brownian dynamics simulations are used to corroborate our approximate analytical results and to establish the range of their applicability.
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Affiliation(s)
- Alexei T Skvortsov
- Maritime Division, Defence Science and Technology, Fishermans Bend, VIC 3207, Australia
| | - Leonardo Dagdug
- Physics Department, Universidad Autonoma Metropolitana-Iztapalapa, 09340 Mexico City, Mexico
| | - Alexander M Berezhkovskii
- Mathematical and Statistical Computing Laboratory, Office of Intramural Research, Center for Information Technology, National Institutes of Health, Bethesda, Maryland 20892, USA.,Section on Molecular Transport, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Ian R MacGillivray
- Maritime Division, Defence Science and Technology, Fishermans Bend, VIC 3207, Australia
| | - 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, USA
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24
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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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Brown KA, Tucholski T, Alpert AJ, Eken C, Wesemann L, Kyrvasilis A, Jin S, Ge Y. Top-Down Proteomics of Endogenous Membrane Proteins Enabled by Cloud Point Enrichment and Multidimensional Liquid Chromatography-Mass Spectrometry. Anal Chem 2020; 92:15726-15735. [PMID: 33231430 PMCID: PMC7968110 DOI: 10.1021/acs.analchem.0c02533] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Although top-down proteomics has emerged as a powerful strategy to characterize proteins in biological systems, the analysis of endogenous membrane proteins remains challenging due to their low solubility, low abundance, and the complexity of the membrane subproteome. Here, we report a simple but effective enrichment and separation strategy for top-down proteomics of endogenous membrane proteins enabled by cloud point extraction and multidimensional liquid chromatography coupled to high-resolution mass spectrometry (MS). The cloud point extraction efficiently enriched membrane proteins using a single extraction, eliminating the need for time-consuming ultracentrifugation steps. Subsequently, size-exclusion chromatography (SEC) with an MS-compatible mobile phase (59% water, 40% isopropanol, 1% formic acid) was used to remove the residual surfactant and fractionate intact proteins (6-115 kDa). The fractions were separated further by reversed-phase liquid chromatography (RPLC) coupled with MS for protein characterization. This method was applied to human embryonic kidney cells and cardiac tissue lysates to enable the identification of 188 and 124 endogenous integral membrane proteins, respectively, some with as many as 19 transmembrane domains.
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Affiliation(s)
- Kyle A. Brown
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Trisha Tucholski
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Andrew J. Alpert
- PolyLC Inc., Columbia, Maryland 21045, United States
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
| | - Christian Eken
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Lucas Wesemann
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
| | - Andreas Kyrvasilis
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
| | - Song Jin
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin, 53706, USA
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
- Human Proteomics Program, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wisconsin, 53705, USA
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26
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Costello MJ, Gilliland KO, Mohamed A, Schey KL, Johnsen S, Brennan LA, Kantorow M. Novel mitochondrial derived Nuclear Excisosome degrades nuclei during differentiation of prosimian Galago (bush baby) monkey lenses. PLoS One 2020; 15:e0241631. [PMID: 33180800 PMCID: PMC7660580 DOI: 10.1371/journal.pone.0241631] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 10/16/2020] [Indexed: 11/18/2022] Open
Abstract
The unique cellular organization and transparent function of the ocular lens depend on the continuous differentiation of immature epithelial cells on the lens anterior surface into mature elongated fiber cells within the lens core. A ubiquitous event during lens differentiation is the complete elimination of organelles required for mature lens fiber cell structure and transparency. Distinct pathways have been identified to mediate the elimination of non-nuclear organelles and nuclei. Recently, we reported the discovery of a unique structure in developing fiber cells of the chick embryo lens, called the Nuclear Excisosome, that is intractably associated with degrading nuclei during lens fiber cell differentiation. In the chick lens, the Nuclear Excisosome is derived from projections of adjacent cells contacting the nuclear envelope during nuclear elimination. Here, we demonstrate that, in contrast to the avian model, Nuclear Excisosomes in a primate model, Galago (bush baby) monkeys, are derived through the recruitment of mitochondria to form unique linear assemblies that define a novel primate Nuclear Excisosome. Four lenses from three monkeys aged 2–5 years were fixed in formalin, followed by paraformaldehyde, then processed for Airyscan confocal microscopy or transmission electron microscopy. For confocal imaging, fluorescent dyes labelled membranes, carbohydrate in the extracellular space, filamentous actin and nuclei. Fiber cells from Galago lenses typically displayed prominent linear structures within the cytoplasm with a distinctive cross-section of four membranes and lengths up to 30 μm. The outer membranes of these linear structures were observed to attach to the outer nuclear envelope membrane to initiate degradation near the organelle-free zone. The origin of these unique structures was mitochondria in the equatorial epithelium (not from plasma membranes of adjacent cells as in the chick embryo model). Early changes in mitochondria appeared to be the collapse of the cristae and modification of one side of the mitochondrial outer membrane to promote accumulation of protein in a dense cluster. As a mitochondrion surrounded the dense protein cluster, an outer mitochondrial membrane enclosed the protein to form a core and another outer mitochondrial membrane formed the outermost layer. The paired membranes of irregular texture between the inner core membrane and the outer limiting membrane appeared to be derived from modified mitochondrial cristae. Several mitochondria were involved in the formation and maturation of these unique complexes that apparently migrated around the fulcrum into the cytoplasm of nascent fiber cells where they were stabilized until the nuclear degradation was initiated. Thus, unlike in the chick embryo, the Galago lenses degraded nuclear envelopes with a Nuclear Excisosome derived from multiple mitochondria in the epithelium that formed novel linear assemblies in developing fiber cells. These findings suggest that recruitment of distinct structures is required for Nuclear Excisosome formation in different species.
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Affiliation(s)
- M Joseph Costello
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC, United States of America
| | - Kurt O Gilliland
- Department of Cell Biology and Physiology, University of North Carolina, Chapel Hill, NC, United States of America
| | - Ashik Mohamed
- Ophthalmic Biophysics, L V Prasad Eye Institute, Hyderabad, Telangana, India
| | - Kevin L Schey
- Biochemistry Department, Vanderbilt University, Nashville, TN, United States of America
| | - Sönke Johnsen
- Biology Department, Duke University, Durham, NC, United States of America
| | - Lisa A Brennan
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL, United States of America
| | - Marc Kantorow
- Department of Biomedical Science, Florida Atlantic University, Boca Raton, FL, United States of America
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27
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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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28
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Multifaceted roles of porin in mitochondrial protein and lipid transport. Biochem Soc Trans 2020; 47:1269-1277. [PMID: 31670371 DOI: 10.1042/bst20190153] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/03/2019] [Accepted: 10/04/2019] [Indexed: 11/17/2022]
Abstract
Mitochondria are essential eukaryotic organelles responsible for primary cellular energy production. Biogenesis, maintenance, and functions of mitochondria require correct assembly of resident proteins and lipids, which require their transport into and within mitochondria. Mitochondrial normal functions also require an exchange of small metabolites between the cytosol and mitochondria, which is primarily mediated by a metabolite channel of the outer membrane (OM) called porin or voltage-dependent anion channel. Here, we describe recently revealed novel roles of porin in the mitochondrial protein and lipid transport. First, porin regulates the formation of the mitochondrial protein import gate in the OM, the translocase of the outer membrane (TOM) complex, and its dynamic exchange between the major form of a trimer and the minor form of a dimer. The TOM complex dimer lacks a core subunit Tom22 and mediates the import of a subset of mitochondrial proteins while the TOM complex trimer facilitates the import of most other mitochondrial proteins. Second, porin interacts with both a translocating inner membrane (IM) protein like a carrier protein accumulated at the small TIM chaperones in the intermembrane space and the TIM22 complex, a downstream translocator in the IM for the carrier protein import. Porin thereby facilitates the efficient transfer of carrier proteins to the IM during their import. Third, porin facilitates the transfer of lipids between the OM and IM and promotes a back-up pathway for the cardiolipin synthesis in mitochondria. Thus, porin has roles more than the metabolite transport in the protein and lipid transport into and within mitochondria, which is likely conserved from yeast to human.
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29
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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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30
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Kaur H, Grahl A, Hartmann JB, Hiller S. Sample Preparation and Technical Setup for NMR Spectroscopy with Integral Membrane Proteins. Methods Mol Biol 2020; 2127:373-396. [PMID: 32112334 DOI: 10.1007/978-1-0716-0373-4_24] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
NMR spectroscopy is a method of choice to characterize structure, function, and dynamics of integral membrane proteins at atomic resolution. Here, we describe protocols for sample preparation and characterization by NMR spectroscopy of two integral membrane proteins with different architecture, the α-helical membrane protein MsbA and the β-barrel membrane protein BamA. The protocols describe recombinant expression in E. coli, protein refolding, purification, and reconstitution in suitable membrane mimetics, as well as key setup steps for basic NMR experiments. These include experiments on protein samples in the solid state under magic angle spinning (MAS) conditions and experiments on protein samples in aqueous solution. Since MsbA and BamA are typical examples of their respective architectural classes, the protocols presented here can also serve as a reference for other integral membrane proteins.
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Affiliation(s)
- Hundeep Kaur
- Biozentrum, University of Basel, Basel, Switzerland
| | - Anne Grahl
- Biozentrum, University of Basel, Basel, Switzerland
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31
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Lopes-Rodrigues M, Matagne A, Zanuy D, Alemán C, Perpète EA, Michaux C. Structural and functional characterization of Solanum tuberosum VDAC36. Proteins 2019; 88:729-739. [PMID: 31833115 DOI: 10.1002/prot.25861] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Revised: 11/26/2019] [Accepted: 12/06/2019] [Indexed: 11/05/2022]
Abstract
As it forms water-filled channel in the mitochondria outer membrane and diffuses essential metabolites such as NADH and ATP, the voltage-dependent anion channel (VDAC) protein family plays a central role in all eukaryotic cells. In comparison with their mammalian homologues, little is known about the structural and functional properties of plant VDACs. In the present contribution, one of the two VDACs isoforms of Solanum tuberosum, stVDAC36, has been successfully overexpressed and refolded by an in-house method, as demonstrated by the information on its secondary and tertiary structure gathered from circular dichroism and intrinsic fluorescence. Cross-linking and molecular modeling studies have evidenced the presence of dimers and tetramers, and they suggest the formation of an intermolecular disulfide bond between two stVDAC36 monomers. The pore-forming activity was also assessed by liposome swelling assays, indicating a typical pore diameter between 2.0 and 2.7 nm. Finally, insights about the ATP binding inside the pore are given by docking studies and electrostatic calculations.
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Affiliation(s)
- Maximilien Lopes-Rodrigues
- Laboratoire de Chimie Physique des Biomolécules, Unité de Chimie Physique Théorique et Structurale (UCPTS), University of Namur, Namur, Belgium.,Namur Institute of Structured Matter, University of Namur, Namur, Belgium.,Departament d'Enginyeria Química, EEBE, Universitat Politècnica de Catalunya, C/Eduard Maristany, Barcelona, Spain.,Barcelona Research Center for Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Eduard Maristany, Barcelona, Spain
| | - André Matagne
- Laboratoire d'Enzymologie et Repliement des Protéines, Centre d'Ingénierie des Protéines (CIP), Université de Liège, Liège, Belgium
| | - David Zanuy
- Departament d'Enginyeria Química, EEBE, Universitat Politècnica de Catalunya, C/Eduard Maristany, Barcelona, Spain
| | - Carlos Alemán
- Departament d'Enginyeria Química, EEBE, Universitat Politècnica de Catalunya, C/Eduard Maristany, Barcelona, Spain.,Barcelona Research Center for Multiscale Science and Engineering, Universitat Politècnica de Catalunya, Eduard Maristany, Barcelona, Spain
| | - Eric A Perpète
- Laboratoire de Chimie Physique des Biomolécules, Unité de Chimie Physique Théorique et Structurale (UCPTS), University of Namur, Namur, Belgium.,Namur Institute of Structured Matter, University of Namur, Namur, Belgium.,Namur Research Institute for Life Sciences, University of Namur, Namur, Belgium
| | - Catherine Michaux
- Laboratoire de Chimie Physique des Biomolécules, Unité de Chimie Physique Théorique et Structurale (UCPTS), University of Namur, Namur, Belgium.,Namur Institute of Structured Matter, University of Namur, Namur, Belgium.,Institute of Life-Earth-Environment, University of Namur, Namur, Belgium
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32
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Unten Y, Murai M, Yamamoto T, Watanabe A, Ichimaru N, Aburaya S, Aoki W, Shinohara Y, Miyoshi H. Pentenediol-Type Compounds Specifically Bind to Voltage-Dependent Anion Channel 1 in Saccharomyces cerevisiae Mitochondria. Biochemistry 2019; 58:1141-1154. [PMID: 30657320 DOI: 10.1021/acs.biochem.8b01209] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Voltage-dependent anion channel 1 (VDAC1) situated in the outer mitochondrial membrane regulates the transfer of various metabolites and is a key player in mitochondria-mediated apoptosis. Although many small chemicals that modulate the functions of VDAC1 have been reported to date, most, if not all, of them cannot be regarded as specific reagents due to their interactions with other transporters or enzymes. By screening our chemical libraries using isolated Saccharomyces cerevisiae mitochondria, we found pentenediol (PTD)-type compounds (e.g., PTD-023) as new specific inhibitors of VDAC1. PTD-023 inhibited overall ADP-uptake/ATP-release reactions in isolated mitochondria at a single digit μM level. To identify the binding position of PTDs in VDAC1 by visualizing PTD-bound peptides, we conducted ligand-directed tosyl (LDT) chemistry using the synthetic LDT reagent t-PTD-023 derived from the parent PTD-023 in combination with mutagenesis experiments. t-PTD-023 made a covalent bond predominantly and subsidiarily with nucleophilic Cys210 and Cys130, respectively, indicating that PTDs bind to the region interactive with both residues. Site-directed mutations of hydrogen bond-acceptable Asp139 and Glu152 to Ala, which were selected as potential interactive partners of the critical pentenediol moiety based on the presumed binding model of PTDs in VDAC1, resulted in a decrease in susceptibility against PTD-023. This result strongly suggests that PTDs bind to VDAC1 through a specific hydrogen bond with the two residues. The present study is the first to demonstrate the binding position of specific inhibitors of VDAC1 at the amino acid level.
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Affiliation(s)
- Yufu Unten
- Division of Applied Life Sciences, Graduate School of Agriculture , Kyoto University , Sakyo-ku, Kyoto 606-8502 , Japan
| | - Masatoshi Murai
- Division of Applied Life Sciences, Graduate School of Agriculture , Kyoto University , Sakyo-ku, Kyoto 606-8502 , Japan
| | - Takenori Yamamoto
- Institute for Genome Research , University of Tokushima , Kuramotocho-3 , Tokushima 770-8503 , Japan
| | - Akira Watanabe
- Institute for Genome Research , University of Tokushima , Kuramotocho-3 , Tokushima 770-8503 , Japan
| | - Naoya Ichimaru
- Division of Applied Life Sciences, Graduate School of Agriculture , Kyoto University , Sakyo-ku, Kyoto 606-8502 , Japan
| | - Shunsuke Aburaya
- Division of Applied Life Sciences, Graduate School of Agriculture , Kyoto University , Sakyo-ku, Kyoto 606-8502 , Japan
| | - Wataru Aoki
- Division of Applied Life Sciences, Graduate School of Agriculture , Kyoto University , Sakyo-ku, Kyoto 606-8502 , Japan
| | - Yasuo Shinohara
- Institute for Genome Research , University of Tokushima , Kuramotocho-3 , Tokushima 770-8503 , Japan
| | - Hideto Miyoshi
- Division of Applied Life Sciences, Graduate School of Agriculture , Kyoto University , Sakyo-ku, Kyoto 606-8502 , Japan
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33
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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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34
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Uno S, Kimura H, Murai M, Miyoshi H. Exploring the quinone/inhibitor-binding pocket in mitochondrial respiratory complex I by chemical biology approaches. J Biol Chem 2018; 294:679-696. [PMID: 30425100 DOI: 10.1074/jbc.ra118.006056] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 11/10/2018] [Indexed: 11/06/2022] Open
Abstract
NADH-quinone oxidoreductase (respiratory complex I) couples NADH-to-quinone electron transfer to the translocation of protons across the membrane. Even though the architecture of the quinone-access channel in the enzyme has been modeled by X-ray crystallography and cryo-EM, conflicting findings raise the question whether the models fully reflect physiologically relevant states present throughout the catalytic cycle. To gain further insights into the structural features of the binding pocket for quinone/inhibitor, we performed chemical biology experiments using bovine heart sub-mitochondrial particles. We synthesized ubiquinones that are oversized (SF-UQs) or lipid-like (PC-UQs) and are highly unlikely to enter and transit the predicted narrow channel. We found that SF-UQs and PC-UQs can be catalytically reduced by complex I, albeit only at moderate or low rates. Moreover, quinone-site inhibitors completely blocked the catalytic reduction and the membrane potential formation coupled to this reduction. Photoaffinity-labeling experiments revealed that amiloride-type inhibitors bind to the interfacial domain of multiple core subunits (49 kDa, ND1, and PSST) and the 39-kDa supernumerary subunit, although the latter does not make up the channel cavity in the current models. The binding of amilorides to the multiple target subunits was remarkably suppressed by other quinone-site inhibitors and SF-UQs. Taken together, the present results are difficult to reconcile with the current channel models. On the basis of comprehensive interpretations of the present results and of previous findings, we discuss the physiological relevance of these models.
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Affiliation(s)
- Shinpei Uno
- From the Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Hironori Kimura
- From the Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Masatoshi Murai
- From the Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Hideto Miyoshi
- From the Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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35
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Manzo G, Serra I, Magrí A, Casu M, De Pinto V, Ceccarelli M, Scorciapino MA. Folded Structure and Membrane Affinity of the N-Terminal Domain of the Three Human Isoforms of the Mitochondrial Voltage-Dependent Anion-Selective Channel. ACS OMEGA 2018; 3:11415-11425. [PMID: 30320261 PMCID: PMC6173511 DOI: 10.1021/acsomega.8b01536] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/11/2018] [Indexed: 06/08/2023]
Abstract
Voltage-dependent anion-selective channels (VDACs) are primarily located in the mitochondrial outer membrane (MOM). They are essential for the regulation of ion and metabolite exchanges. In particular, their role in energy-related nucleotide exchange has many implications in apoptosis, cancer, and neurodegenerative diseases. It has been proposed that VDACs' functions are regulated by mobility of the N-terminal helical domain, which is bound to the inner wall of the main β-barrel domain but exists in equilibrium between the bound-folded and the unbound-unfolded state. When the N-terminal domain detaches from the channel's wall and eventually leaves the lumen, it can either stay exposed to the cytosolic environment or interact with the outer leaflet of the MOM; then, it may also interact with other protein partners. In humans, three different VDAC isoforms are expressed at different tissue-specific levels with evidence of distinct roles. Although the N-terminal domains share high sequence similarity, important differences do exist, with the functionality of the entire protein mostly attributed to them. In this work, the three-dimensional structure and membrane affinity of the three isolated hVDAC N-terminal peptides have been compared through Fourier-transform infrared and NMR spectroscopy in combination with molecular dynamics simulations, and measurement of the surface pressure of lipid monolayers. Although peptides were studied as isolated from the β-barrel domain, the observed differences are relevant for those whole protein's functions in which a protein-protein interaction is mediated by the N-terminal domain.
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Affiliation(s)
- Giorgia Manzo
- Department
of Chemical and Geological Sciences, Cittadella Universitaria di Monserrato, Department of Physics,
Cittadella Universitaria di Monserrato, and Department
of Biomedical Sciences, Biochemistry Unit, Cittadella Universitaria
di Monserrato, University of Cagliari, S.P. 8 km 0.700, 09042 Monserrato, Cagliari, Italy
| | - Ilaria Serra
- Department
of Chemical and Geological Sciences, Cittadella Universitaria di Monserrato, Department of Physics,
Cittadella Universitaria di Monserrato, and Department
of Biomedical Sciences, Biochemistry Unit, Cittadella Universitaria
di Monserrato, University of Cagliari, S.P. 8 km 0.700, 09042 Monserrato, Cagliari, Italy
| | - Andrea Magrí
- Department of Biomedicine
and Biotechnology, Section of Biology and Genetics, University of Catania, Via Santa Sofia 97, 95123 Catania, Italy
| | - Mariano Casu
- Department
of Chemical and Geological Sciences, Cittadella Universitaria di Monserrato, Department of Physics,
Cittadella Universitaria di Monserrato, and Department
of Biomedical Sciences, Biochemistry Unit, Cittadella Universitaria
di Monserrato, University of Cagliari, S.P. 8 km 0.700, 09042 Monserrato, Cagliari, Italy
| | - Vito De Pinto
- Department of Biomedicine
and Biotechnology, Section of Biology and Genetics, University of Catania, Via Santa Sofia 97, 95123 Catania, Italy
| | - Matteo Ceccarelli
- Department
of Chemical and Geological Sciences, Cittadella Universitaria di Monserrato, Department of Physics,
Cittadella Universitaria di Monserrato, and Department
of Biomedical Sciences, Biochemistry Unit, Cittadella Universitaria
di Monserrato, University of Cagliari, S.P. 8 km 0.700, 09042 Monserrato, Cagliari, Italy
| | - Mariano Andrea Scorciapino
- Department
of Chemical and Geological Sciences, Cittadella Universitaria di Monserrato, Department of Physics,
Cittadella Universitaria di Monserrato, and Department
of Biomedical Sciences, Biochemistry Unit, Cittadella Universitaria
di Monserrato, University of Cagliari, S.P. 8 km 0.700, 09042 Monserrato, Cagliari, Italy
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36
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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: 44] [Impact Index Per Article: 7.3] [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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37
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Becker T, Wagner R. Mitochondrial Outer Membrane Channels: Emerging Diversity in Transport Processes. Bioessays 2018; 40:e1800013. [DOI: 10.1002/bies.201800013] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 03/29/2018] [Indexed: 01/06/2023]
Affiliation(s)
- Thomas Becker
- Faculty of MedicineInstitute of Biochemistry and Molecular Biology, ZBMZUniversity of FreiburgFreiburgD‐79104Germany
- BIOSS Centre for Biological Signalling StudiesUniversity of FreiburgFreiburgD‐79104Germany
| | - Richard Wagner
- Biophysics, Life Sciences & ChemistryJacobs University BremenBremenD‐28759Germany
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38
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Abstract
Cancer metabolism is emerging as a chemotherapeutic target. Enhanced glycolysis and suppression of mitochondrial metabolism characterize the Warburg phenotype in cancer cells. The flux of respiratory substrates, ADP, and Pi into mitochondria and the release of mitochondrial ATP to the cytosol occur through voltage-dependent anion channels (VDACs) located in the mitochondrial outer membrane. Catabolism of respiratory substrates in the Krebs cycle generates NADH and FADH2 that enter the electron transport chain (ETC) to generate a proton motive force that maintains mitochondrial membrane potential (ΔΨ) and is utilized to generate ATP. The ETC is also the major cellular source of mitochondrial reactive oxygen species (ROS). αβ-Tubulin heterodimers decrease VDAC conductance in lipid bilayers. High constitutive levels of cytosolic free tubulin in intact cancer cells close VDAC decreasing mitochondrial ΔΨ and mitochondrial metabolism. The VDAC-tubulin interaction regulates VDAC opening and globally controls mitochondrial metabolism, ROS formation, and the intracellular flow of energy. Erastin, a VDAC-binding molecule lethal to some cancer cell types, and erastin-like compounds identified in a high-throughput screening antagonize the inhibitory effect of tubulin on VDAC. Reversal of tubulin inhibition of VDAC increases VDAC conductance and the flux of metabolites into and out of mitochondria. VDAC opening promotes a higher mitochondrial ΔΨ and a global increase in mitochondrial metabolism leading to high cytosolic ATP/ADP ratios that inhibit glycolysis. VDAC opening also increases ROS production causing oxidative stress that, in turn, leads to mitochondrial dysfunction, bioenergetic failure, and cell death. In summary, antagonism of the VDAC-tubulin interaction promotes cell death by a "double-hit model" characterized by reversion of the proproliferative Warburg phenotype (anti-Warburg) and promotion of oxidative stress.
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Affiliation(s)
- Diana Fang
- Medical University of South Carolina, Charleston, SC, United States
| | - Eduardo N Maldonado
- 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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39
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Lemasters JJ. Evolution of Voltage-Dependent Anion Channel Function: From Molecular Sieve to Governator to Actuator of Ferroptosis. Front Oncol 2017; 7:303. [PMID: 29312883 PMCID: PMC5742158 DOI: 10.3389/fonc.2017.00303] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2017] [Accepted: 11/24/2017] [Indexed: 01/07/2023] Open
Abstract
The voltage-dependent anion channel (VDAC) is well known as the pathway for passive diffusion of anionic hydrophilic mitochondrial metabolites across the outer membrane, but a more complex functionality of the three isoforms of VDAC has emerged, as addressed in the Frontiers in Oncology Research Topic on “Uncovering the Function of the Mitochondrial Protein VDAC in Health and Disease: from Structure-Function to Novel Therapeutic Strategies.” VDAC as the single most abundant protein in mitochondrial outer membranes is typically involved in isoform-specific interactions of the mitochondrion with its surroundings as, for example, during mitochondria-dependent pathways of cell death. VDAC closure can also act as an adjustable limiter (governator) of global mitochondrial metabolism, as during hepatic ethanol metabolism to promote selective oxidation of membrane-permeant acetaldehyde. In cancer cells, high free tubulin inhibits VDAC1 and VDAC2, contributing to suppression of mitochondrial function in the Warburg phenomenon. Erastin, the canonical inducer of ferroptosis, opens VDAC in the presence of tubulin and hyperpolarizes mitochondria, leading to mitochondrial production of reactive oxygen species, mitochondrial dysfunction, and cell death. Our understanding of VDAC function continues to evolve.
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Affiliation(s)
- John J Lemasters
- Center for Cell Death, Injury and Regeneration, Department of Drug Discovery and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, United States.,Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, United States
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40
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González-Durruthy M, Werhli AV, Seus V, Machado KS, Pazos A, Munteanu CR, González-Díaz H, Monserrat JM. Decrypting Strong and Weak Single-Walled Carbon Nanotubes Interactions with Mitochondrial Voltage-Dependent Anion Channels Using Molecular Docking and Perturbation Theory. Sci Rep 2017; 7:13271. [PMID: 29038520 PMCID: PMC5643473 DOI: 10.1038/s41598-017-13691-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 09/25/2017] [Indexed: 01/30/2023] Open
Abstract
The current molecular docking study provided the Free Energy of Binding (FEB) for the interaction (nanotoxicity) between VDAC mitochondrial channels of three species (VDAC1-Mus musculus, VDAC1-Homo sapiens, VDAC2-Danio rerio) with SWCNT-H, SWCNT-OH, SWCNT-COOH carbon nanotubes. The general results showed that the FEB values were statistically more negative (p < 0.05) in the following order: (SWCNT-VDAC2-Danio rerio) > (SWCNT-VDAC1-Mus musculus) > (SWCNT-VDAC1-Homo sapiens) > (ATP-VDAC). More negative FEB values for SWCNT-COOH and OH were found in VDAC2-Danio rerio when compared with VDAC1-Mus musculus and VDAC1-Homo sapiens (p < 0.05). In addition, a significant correlation (0.66 > r2 > 0.97) was observed between n-Hamada index and VDAC nanotoxicity (or FEB) for the zigzag topologies of SWCNT-COOH and SWCNT-OH. Predictive Nanoparticles-Quantitative-Structure Binding-Relationship models (nano-QSBR) for strong and weak SWCNT-VDAC docking interactions were performed using Perturbation Theory, regression and classification models. Thus, 405 SWCNT-VDAC interactions were predicted using a nano-PT-QSBR classifications model with high accuracy, specificity, and sensitivity (73–98%) in training and validation series, and a maximum AUROC value of 0.978. In addition, the best regression model was obtained with Random Forest (R2 of 0.833, RMSE of 0.0844), suggesting an excellent potential to predict SWCNT-VDAC channel nanotoxicity. All study data are available at https://doi.org/10.6084/m9.figshare.4802320.v2.
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Affiliation(s)
- Michael González-Durruthy
- Institute of Biological Sciences (ICB)- Federal University of Rio Grande - FURG, Postgraduate Program in Physiological Sciences, Cx. P. 474, CEP 96200-970, Rio Grande, RS, Brazil.
| | - Adriano V Werhli
- Center of Computational Sciences (C3)- Federal University of Rio Grande - FURG, Cx. P. 474, CEP 96200-970, Rio Grande, RS, Brazil
| | - Vinicius Seus
- Center of Computational Sciences (C3)- Federal University of Rio Grande - FURG, Cx. P. 474, CEP 96200-970, Rio Grande, RS, Brazil
| | - Karina S Machado
- Center of Computational Sciences (C3)- Federal University of Rio Grande - FURG, Cx. P. 474, CEP 96200-970, Rio Grande, RS, Brazil
| | - Alejandro Pazos
- Biomedical Research Institute of A Coruña (INIBIC), University Hospital Complex of A Coruña (CHUAC), A Coruña, 15006, Spain.,RNASA-IMEDIR, Computer Science Faculty, University of A Coruña, Campus de Elviña s/n, 15071, A Coruña, Spain
| | - Cristian R Munteanu
- RNASA-IMEDIR, Computer Science Faculty, University of A Coruña, Campus de Elviña s/n, 15071, A Coruña, Spain
| | - Humberto González-Díaz
- Department of Organic Chemistry II, University of the Basque Country UPV/EHU, 48940, Leioa, Spain.,IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain
| | - José M Monserrat
- Institute of Biological Sciences (ICB)- Federal University of Rio Grande - FURG, Postgraduate Program in Physiological Sciences, Cx. P. 474, CEP 96200-970, Rio Grande, RS, Brazil
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41
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Krüger V, Becker T, Becker L, Montilla-Martinez M, Ellenrieder L, Vögtle FN, Meyer HE, Ryan MT, Wiedemann N, Warscheid B, Pfanner N, Wagner R, Meisinger C. Identification of new channels by systematic analysis of the mitochondrial outer membrane. J Cell Biol 2017; 216:3485-3495. [PMID: 28916712 PMCID: PMC5674900 DOI: 10.1083/jcb.201706043] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 08/03/2017] [Accepted: 08/22/2017] [Indexed: 02/08/2023] Open
Abstract
Channels in the mitochondrial outer membrane exchange metabolites, ions, and proteins with the rest of the cell. Kruger et al. identify several new types of channel and suggest that the outer mitochondrial membrane is a more selective molecular sieve with a greater variety of channel-forming proteins than previously appreciated. The mitochondrial outer membrane is essential for communication between mitochondria and the rest of the cell and facilitates the transport of metabolites, ions, and proteins. All mitochondrial outer membrane channels known to date are β-barrel membrane proteins, including the abundant voltage-dependent anion channel and the cation-preferring protein-conducting channels Tom40, Sam50, and Mdm10. We analyzed outer membrane fractions of yeast mitochondria and identified four new channel activities: two anion-preferring channels and two cation-preferring channels. We characterized the cation-preferring channels at the molecular level. The mitochondrial import component Mim1 forms a channel that is predicted to have an α-helical structure for protein import. The short-chain dehydrogenase-related protein Ayr1 forms an NADPH-regulated channel. We conclude that the mitochondrial outer membrane contains a considerably larger variety of channel-forming proteins than assumed thus far. These findings challenge the traditional view of the outer membrane as an unspecific molecular sieve and indicate a higher degree of selectivity and regulation of metabolite fluxes at the mitochondrial boundary.
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Affiliation(s)
- Vivien Krüger
- Division of Biophysics, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany.,Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Thomas Becker
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Lars Becker
- Division of Biophysics, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
| | | | - Lars Ellenrieder
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - F-Nora Vögtle
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Helmut E Meyer
- Leibniz-Institut für Analytische Wissenschaften-ISAS-e.V., Dortmund, Germany
| | - Michael T Ryan
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, Melbourne, Australia
| | - Nils Wiedemann
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Bettina Warscheid
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany.,Institute of Biology II, Biochemistry - Functional Proteomics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Nikolaus Pfanner
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany .,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Richard Wagner
- Division of Biophysics, School of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany .,Biophysics, Life Sciences and Chemistry, Jacobs University Bremen, Bremen, Germany
| | - Chris Meisinger
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
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42
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He L, Hu X, Zhu M, Liang Z, Chen F, Zhu L, Kuang S, Cao G, Xue R, Gong C. Identification and characterization of vp7 gene in Bombyx mori cytoplasmic polyhedrosis virus. Gene 2017; 627:343-350. [PMID: 28668346 PMCID: PMC7173298 DOI: 10.1016/j.gene.2017.06.048] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2016] [Revised: 05/31/2017] [Accepted: 06/27/2017] [Indexed: 01/15/2023]
Abstract
The genome of Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) contains 10 double stranded RNA segments (S1-S10). The segment 7 (S7) encodes 50kDa protein which is considered as a structural protein. The expression pattern and function of p50 in the virus life cycle are still unclear. In this study, the viral structural protein 7 (VP7) polyclonal antibody was prepared with immunized mouse to explore the presence of small VP7 gene-encoded proteins in Bombyx mori cytoplasmic polyhedrosis virus. The expression pattern of vp7 gene was investigated by its overexpression in BmN cells. In addition to VP7, supplementary band was identified with western blotting technique. The virion, BmCPV infected cells and midguts were also examined using western blotting technique. 4, 2 and 5 bands were detected in the corresponding samples, respectively. The replication of BmCPV genome in the cultured cells and midgut of silkworm was decreased by reducing the expression level of vp7 gene using RNA interference. In immunoprecipitation experiments, using a polyclonal antiserum directed against the VP7, one additional shorter band in BmCPV infected midguts was detected, and then the band was analyzed with mass spectrum (MS), the MS results showed thatone candidate interacted protein (VP7 voltage-dependent anion-selective channel-like isoform, VDAC) was identified from silkworm. We concluded that the novel viral product was generated with a leaky scanning mechanism and the VDAC may be an interacted protein with VP7.
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Affiliation(s)
- Lei He
- School of Biology & Basic Medical Science, Soochow University, Suzhou 215123, China
| | - Xiaolong Hu
- School of Biology & Basic Medical Science, Soochow University, Suzhou 215123, China; National Engineering Laboratory for Modern Silk, Soochow University, Suzhou 215123, China
| | - Min Zhu
- School of Biology & Basic Medical Science, Soochow University, Suzhou 215123, China
| | - Zi Liang
- School of Biology & Basic Medical Science, Soochow University, Suzhou 215123, China
| | - Fei Chen
- School of Biology & Basic Medical Science, Soochow University, Suzhou 215123, China
| | - Liyuan Zhu
- School of Biology & Basic Medical Science, Soochow University, Suzhou 215123, China
| | - Sulan Kuang
- School of Biology & Basic Medical Science, Soochow University, Suzhou 215123, China
| | - Guangli Cao
- School of Biology & Basic Medical Science, Soochow University, Suzhou 215123, China; National Engineering Laboratory for Modern Silk, Soochow University, Suzhou 215123, China
| | - Renyu Xue
- School of Biology & Basic Medical Science, Soochow University, Suzhou 215123, China; National Engineering Laboratory for Modern Silk, Soochow University, Suzhou 215123, China
| | - Chengliang Gong
- School of Biology & Basic Medical Science, Soochow University, Suzhou 215123, China; National Engineering Laboratory for Modern Silk, Soochow University, Suzhou 215123, China.
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43
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Iyer BR, Zadafiya P, Vetal PV, Mahalakshmi R. Energetics of side-chain partitioning of β-signal residues in unassisted folding of a transmembrane β-barrel protein. J Biol Chem 2017; 292:12351-12365. [PMID: 28592485 PMCID: PMC5519381 DOI: 10.1074/jbc.m117.789446] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 06/02/2017] [Indexed: 01/07/2023] Open
Abstract
The free energy of water-to-interface amino acid partitioning is a major contributing factor in membrane protein folding and stability. The interface residues at the C terminus of transmembrane β-barrels form the β-signal motif required for assisted β-barrel assembly in vivo but are believed to be less important for β-barrel assembly in vitro. Here, we experimentally measured the thermodynamic contribution of all 20 amino acids at the β-signal motif to the unassisted folding of the model β-barrel protein PagP. We obtained the partitioning free energy for all 20 amino acids at the lipid-facing interface (ΔΔG0w,i(φ)) and the protein-facing interface (ΔΔG0w,i(π)) residues and found that hydrophobic amino acids are most favorably transferred to the lipid-facing interface, whereas charged and polar groups display the highest partitioning energy. Furthermore, the change in non-polar surface area correlated directly with the partitioning free energy for the lipid-facing residue and inversely with the protein-facing residue. We also demonstrate that the interface residues of the β-signal motif are vital for in vitro barrel assembly, because they exhibit a side chain–specific energetic contribution determined by the change in nonpolar accessible surface. We further establish that folding cooperativity and hydrophobic collapse are balanced at the membrane interface for optimal stability of the PagP β-barrel scaffold. We conclude that the PagP C-terminal β-signal motif influences the folding cooperativity and stability of the folded β-barrel and that the thermodynamic contributions of the lipid- and protein-facing residues in the transmembrane protein β-signal motif depend on the nature of the amino acid side chain.
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Affiliation(s)
- Bharat Ramasubramanian Iyer
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhauri, Bhopal 462066, India
| | - Punit Zadafiya
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhauri, Bhopal 462066, India
| | - Pallavi Vijay Vetal
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhauri, Bhopal 462066, India
| | - Radhakrishnan Mahalakshmi
- Molecular Biophysics Laboratory, Department of Biological Sciences, Indian Institute of Science Education and Research, Bhauri, Bhopal 462066, India.
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44
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Gupta R, Ghosh S. Phosphorylation of purified mitochondrial Voltage-Dependent Anion Channel by c-Jun N-terminal Kinase-3 modifies channel voltage-dependence. BIOCHIMIE OPEN 2017; 4:78-87. [PMID: 29450145 PMCID: PMC5802065 DOI: 10.1016/j.biopen.2017.03.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 03/02/2017] [Indexed: 02/05/2023]
Abstract
Voltage-Dependent Anion Channel (VDAC) phosphorylated by c-Jun N-terminal Kinase-3 (JNK3) was incorporated into the bilayer lipid membrane. Single-channel electrophysiological properties of the native and the phosphorylated VDAC were compared. The open probability versus voltage curve of the native VDAC displayed symmetry around the voltage axis, whereas that of the phosphorylated VDAC showed asymmetry. This result indicates that phosphorylation by JNK3 modifies voltage-dependence of VDAC.
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Affiliation(s)
- Rajeev Gupta
- Department of Physiology, All India Institute of Medical Sciences, New Delhi, India
| | - Subhendu Ghosh
- Department of Biophysics, University of Delhi South Campus, India
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45
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Granzyme B enters the mitochondria in a Sam50-, Tim22- and mtHsp70-dependent manner to induce apoptosis. Cell Death Differ 2017; 24:747-758. [PMID: 28338658 DOI: 10.1038/cdd.2017.3] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 12/07/2016] [Accepted: 12/23/2016] [Indexed: 12/22/2022] Open
Abstract
We have found that granzyme B (GB)-induced apoptosis also requires reactive oxygen species resulting from the alteration of mitochondrial complex I. How GB, which does not possess a mitochondrial targeting sequence, enter this organelle is unknown. We show that GB enters the mitochondria independently of the translocase of the outer mitochondrial membrane complex, but requires instead Sam50, the central subunit of the sorting and assembly machinery that integrates outer membrane β-barrel proteins. Moreover, GB breaches the inner membrane through Tim22, the metabolite carrier translocase pore, in a mitochondrial heat-shock protein 70 (mtHsp70)-dependent manner. Granzyme A (GA) and caspase-3 use a similar route to the mitochondria. Finally, preventing GB from entering the mitochondria either by mutating lysine 243 and arginine 244 or depleting Sam50 renders cells more resistant to GB-mediated reactive oxygen species and cell death. Similarly, Sam50 depletion protects cells from GA-, GM- and caspase-3-mediated cell death. Therefore, cytotoxic molecules enter the mitochondria to induce efficiently cell death through a noncanonical Sam50-, Tim22- and mtHsp70-dependent import pathway.
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46
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Lee SY, Kang MG, Shin S, Kwak C, Kwon T, Seo JK, Kim JS, Rhee HW. Architecture Mapping of the Inner Mitochondrial Membrane Proteome by Chemical Tools in Live Cells. J Am Chem Soc 2017; 139:3651-3662. [DOI: 10.1021/jacs.6b10418] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
| | | | - Sanghee Shin
- Center
for RNA Research, Institute of Basic Science (IBS), Seoul 08826, Korea
- School
of Biological Sciences, Seoul National University, Seoul 08826, Korea
| | | | | | | | - Jong-Seo Kim
- Center
for RNA Research, Institute of Basic Science (IBS), Seoul 08826, Korea
- School
of Biological Sciences, Seoul National University, Seoul 08826, Korea
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47
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Maldonado EN. VDAC-Tubulin, an Anti-Warburg Pro-Oxidant Switch. Front Oncol 2017; 7:4. [PMID: 28168164 PMCID: PMC5256068 DOI: 10.3389/fonc.2017.00004] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 01/05/2017] [Indexed: 12/11/2022] Open
Abstract
Aerobic enhanced glycolysis characterizes the Warburg phenotype. In cancer cells, suppression of mitochondrial metabolism contributes to maintain a low ATP/ADP ratio that favors glycolysis. We propose that the voltage-dependent anion channel (VDAC) located in the mitochondrial outer membrane is a metabolic link between glycolysis and oxidative phosphorylation in the Warburg phenotype. Most metabolites including respiratory substrates, ADP, and Pi enter mitochondria only through VDAC. Oxidation of respiratory substrates in the Krebs cycle generates NADH that enters the electron transport chain (ETC) to generate a proton motive force utilized to generate ATP and to maintain mitochondrial membrane potential (ΔΨ). The ETC is also the major source of mitochondrial reactive oxygen species (ROS) formation. Dimeric α-β tubulin decreases conductance of VDAC inserted in lipid bilayers, and high free tubulin in cancer cells by closing VDAC, limits the ingress of respiratory substrates and ATP decreasing mitochondrial ΔΨ. VDAC opening regulated by free tubulin operates as a “master key” that “seal–unseal” mitochondria to modulate mitochondrial metabolism, ROS formation, and the intracellular flow of energy. Erastin, a small molecule that binds to VDAC and kills cancer cells, and erastin-like compounds antagonize the inhibitory effect of tubulin on VDAC. Blockage of the VDAC–tubulin switch increases mitochondrial metabolism leading to decreased glycolysis and oxidative stress that promotes mitochondrial dysfunction, bioenergetic failure, and cell death. In summary, VDAC opening-dependent cell death follows a “metabolic double-hit model” characterized by oxidative stress and reversion of the pro-proliferative Warburg phenotype.
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Affiliation(s)
- Eduardo N Maldonado
- Department of Pharmaceutical and Biomedical Sciences, Medical University of South Carolina, Charleston, SC, USA; Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, USA; Center for Cell Death, Injury and Regeneration, Medical University of South Carolina, Charleston, SC, USA
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48
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Murai M, Okuda A, Yamamoto T, Shinohara Y, Miyoshi H. Synthetic Ubiquinones Specifically Bind to Mitochondrial Voltage-Dependent Anion Channel 1 (VDAC1) in Saccharomyces cerevisiae Mitochondria. Biochemistry 2017; 56:570-581. [DOI: 10.1021/acs.biochem.6b01011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Masatoshi Murai
- Division
of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Ayaka Okuda
- Division
of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
| | - Takenori Yamamoto
- Institute
for Genome Research, University of Tokushima, Kuramotocho-3, Tokushima 770-8503, Japan
| | - Yasuo Shinohara
- Institute
for Genome Research, University of Tokushima, Kuramotocho-3, Tokushima 770-8503, Japan
| | - Hideto Miyoshi
- Division
of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan
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49
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Size-dependent forced PEG partitioning into channels: VDAC, OmpC, and α-hemolysin. Proc Natl Acad Sci U S A 2016; 113:9003-8. [PMID: 27466408 DOI: 10.1073/pnas.1602716113] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Nonideal polymer mixtures of PEGs of different molecular weights partition differently into nanosize protein channels. Here, we assess the validity of the recently proposed theoretical approach of forced partitioning for three structurally different β-barrel channels: voltage-dependent anion channel from outer mitochondrial membrane VDAC, bacterial porin OmpC (outer membrane protein C), and bacterial channel-forming toxin α-hemolysin. Our interpretation is based on the idea that relatively less-penetrating polymers push the more easily penetrating ones into nanosize channels in excess of their bath concentration. Comparison of the theory with experiments is excellent for VDAC. Polymer partitioning data for the other two channels are consistent with theory if additional assumptions regarding the energy penalty of pore penetration are included. The obtained results demonstrate that the general concept of "polymers pushing polymers" is helpful in understanding and quantification of concrete examples of size-dependent forced partitioning of polymers into protein nanopores.
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50
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Zhang X, Ling Y, Guo Y, Bai Y, Shi X, Gong F, Tan P, Zhang Y, Wei C, He X, Ramirez A, Liu X, Cao C, Zhong H, Xu Q, Ma RZ. Mps1 kinase regulates tumor cell viability via its novel role in mitochondria. Cell Death Dis 2016; 7:e2292. [PMID: 27383047 PMCID: PMC4973343 DOI: 10.1038/cddis.2016.193] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 06/01/2016] [Accepted: 06/03/2016] [Indexed: 12/22/2022]
Abstract
Targeting mitotic kinase monopolar spindle 1 (Mps1) for tumor therapy has been investigated for many years. Although it was suggested that Mps1 regulates cell viability through its role in spindle assembly checkpoint (SAC), the underlying mechanism remains less defined. In an endeavor to reveal the role of high levels of mitotic kinase Mps1 in the development of colon cancer, we unexpectedly found the amount of Mps1 required for cell survival far exceeds that of maintaining SAC in aneuploid cell lines. This suggests that other functions of Mps1 besides SAC are also employed to maintain cell viability. Mps1 regulates cell viability independent of its role in cytokinesis as the genetic depletion of Mps1 spanning from metaphase to cytokinesis affects neither cytokinesis nor cell viability. Furthermore, we developed a single-cycle inhibition strategy that allows disruption of Mps1 function only in mitosis. Using this strategy, we found the functions of Mps1 in mitosis are vital for cell viability as short-term treatment of mitotic colon cancer cell lines with Mps1 inhibitors is sufficient to cause cell death. Interestingly, Mps1 inhibitors synergize with microtubule depolymerizing drug in promoting polyploidization but not in tumor cell growth inhibition. Finally, we found that Mps1 can be recruited to mitochondria by binding to voltage-dependent anion channel 1 (VDAC1) via its C-terminal fragment. This interaction is essential for cell viability as Mps1 mutant defective for interaction fails to main cell viability, causing the release of cytochrome c. Meanwhile, deprivation of VDAC1 can make tumor cells refractory to loss of Mps1-induced cell death. Collectively, we conclude that inhibition of the novel mitochondrial function Mps1 is sufficient to kill tumor cells.
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Affiliation(s)
- X Zhang
- State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Y Ling
- Beijing Institute of Biotechnology, Beijing 100850, China
| | - Y Guo
- State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.,Graduate School, University of the Chinese Academy of Sciences, Beijing 100149, China
| | - Y Bai
- Beijing Institute of Biotechnology, Beijing 100850, China
| | - X Shi
- State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.,Graduate School, University of the Chinese Academy of Sciences, Beijing 100149, China
| | - F Gong
- State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.,Graduate School, University of the Chinese Academy of Sciences, Beijing 100149, China
| | - P Tan
- State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Y Zhang
- Beijing Institute of Biotechnology, Beijing 100850, China
| | - C Wei
- Beijing Institute of Biotechnology, Beijing 100850, China
| | - X He
- Beijing Institute of Biotechnology, Beijing 100850, China
| | - A Ramirez
- University of Colorado at Boulder, Boulder, CO 80302, USA
| | - X Liu
- University of Colorado at Boulder, Boulder, CO 80302, USA
| | - C Cao
- Beijing Institute of Biotechnology, Beijing 100850, China
| | - H Zhong
- Beijing Institute of Biotechnology, Beijing 100850, China
| | - Q Xu
- Beijing Institute of Biotechnology, Beijing 100850, China
| | - R Z Ma
- State Key Laboratory for Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.,Graduate School, University of the Chinese Academy of Sciences, Beijing 100149, China
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