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Hashmi F, Kane PM. V-ATPase Disassembly at the Yeast Lysosome-Like Vacuole Is a Phenotypic Driver of Lysosome Dysfunction in Replicative Aging. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.23.604825. [PMID: 39091794 PMCID: PMC11291124 DOI: 10.1101/2024.07.23.604825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 08/04/2024]
Abstract
Declines in lysosomal acidification and function with aging are observed in organisms ranging from yeast to humans. V-ATPases play a central role in organelle acidification and V-ATPase activity is regulated by reversible disassembly in many different settings. Using the yeast Saccharomyces cerevisiae as a replicative aging model, we demonstrate that V-ATPases disassemble into their V1 and V0 subcomplexes in aging cells, with release of V1 subunit C (Vma5) from the lysosome-like vacuole into the cytosol. Disassembly is observed after ≥5 cell divisions and results in overall vacuole alkalinization. Caloric restriction, an established mechanism for reversing many age-related outcomes, prevents V-ATPase disassembly in older cells and preserves vacuolar pH homeostasis. Reversible disassembly is controlled in part by the activity of two opposing and conserved factors, the RAVE complex and Oxr1. The RAVE complex promotes V-ATPase assembly and a rav1Δ mutant shortens replicative lifespan; Oxr1 promotes disassembly and an oxr1Δ mutation extends lifespan. Importantly, the level of Rav2, a key subunit of the RAVE complex, declines in aged cells. These data indicate that reduced V-ATPase assembly contributes to the loss of lysosome acidification with age, which affects replicative lifespan.
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Affiliation(s)
- Fiza Hashmi
- Department of Biochemistry and Molecular Biology , SUNY Upstate Medical University, Syracuse, NY USA
| | - Patricia M Kane
- Department of Biochemistry and Molecular Biology , SUNY Upstate Medical University, Syracuse, NY USA
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2
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Wang N, Ren L, Danser AHJ. Vacuolar H +-ATPase in Diabetes, Hypertension, and Atherosclerosis. Microcirculation 2024; 31:e12855. [PMID: 38683673 DOI: 10.1111/micc.12855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 03/29/2024] [Accepted: 04/15/2024] [Indexed: 05/02/2024]
Abstract
Vacuolar H+-ATPase (V-ATPase) is a multisubunit protein complex which, along with its accessory proteins, resides in almost every eukaryotic cell. It acts as a proton pump and as such is responsible for regulating pH in lysosomes, endosomes, and the extracellular space. Moreover, V-ATPase has been implicated in receptor-mediated signaling. Although numerous studies have explored the role of V-ATPase in cancer, osteoporosis, and neurodegenerative diseases, research on its involvement in vascular disease remains limited. Vascular diseases pose significant challenges to human health. This review aimed to shed light on the role of V-ATPase in hypertension and atherosclerosis. Furthermore, given that vascular complications are major complications of diabetes, this review also discusses the pathways through which V-ATPase may contribute to such complications. Beginning with an overview of the structure and function of V-ATPase in hypertension, atherosclerosis, and diabetes, this review ends by exploring the pharmacological potential of targeting V-ATPase.
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Affiliation(s)
- Na Wang
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands
- Clinical Research Center, The First Affiliated Hospital of Shantou University Medical College, Shantou, China
| | - Liwei Ren
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands
- Department of Pharmacy, Shenzhen People's Hospital (The Second Clinical Medical College, Jinan University, The First Affiliated Hospital, Southern University of Science and Technology), Shenzhen, China
| | - A H Jan Danser
- Division of Vascular Medicine and Pharmacology, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands
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3
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Klössel S, Zhu Y, Amado L, Bisinski DD, Ruta J, Liu F, González Montoro A. Yeast TLDc domain proteins regulate assembly state and subcellular localization of the V-ATPase. EMBO J 2024; 43:1870-1897. [PMID: 38589611 PMCID: PMC11066047 DOI: 10.1038/s44318-024-00097-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Revised: 03/06/2024] [Accepted: 03/08/2024] [Indexed: 04/10/2024] Open
Abstract
Yeast vacuoles perform crucial cellular functions as acidic degradative organelles, storage compartments, and signaling hubs. These functions are mediated by important protein complexes, including the vacuolar-type H+-ATPase (V-ATPase), responsible for organelle acidification. To gain a more detailed understanding of vacuole function, we performed cross-linking mass spectrometry on isolated vacuoles, detecting many known as well as novel protein-protein interactions. Among these, we identified the uncharacterized TLDc-domain-containing protein Rtc5 as a novel interactor of the V-ATPase. We further analyzed the influence of Rtc5 and of Oxr1, the only other yeast TLDc-domain-containing protein, on V-ATPase function. We find that both Rtc5 and Oxr1 promote the disassembly of the vacuolar V-ATPase in vivo, counteracting the role of the RAVE complex, a V-ATPase assembly chaperone. Furthermore, Oxr1 is necessary for the retention of a Golgi-specific subunit of the V-ATPase in this compartment. Collectively, our results shed light on the in vivo roles of yeast TLDc-domain proteins as regulators of the V-ATPase, highlighting the multifaceted regulation of this crucial protein complex.
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Affiliation(s)
- Samira Klössel
- Osnabrück University, Department of Biology/Chemistry, Cellular Communication Laboratory, Barbarastrasse 13, 49076, Osnabrück, Germany
| | - Ying Zhu
- Department of Structural Biology, Leibniz - Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Roessle-Str. 10, Berlin, 13125, Germany
| | - Lucia Amado
- Osnabrück University, Department of Biology/Chemistry, Cellular Communication Laboratory, Barbarastrasse 13, 49076, Osnabrück, Germany
| | - Daniel D Bisinski
- Osnabrück University, Department of Biology/Chemistry, Cellular Communication Laboratory, Barbarastrasse 13, 49076, Osnabrück, Germany
| | - Julia Ruta
- Department of Structural Biology, Leibniz - Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Roessle-Str. 10, Berlin, 13125, Germany
| | - Fan Liu
- Department of Structural Biology, Leibniz - Forschungsinstitut für Molekulare Pharmakologie (FMP), Robert-Roessle-Str. 10, Berlin, 13125, Germany
- Charité - Universitätsmedizin Berlin, Charitépl. 1, 10117, Berlin, Germany
| | - Ayelén González Montoro
- Osnabrück University, Department of Biology/Chemistry, Cellular Communication Laboratory, Barbarastrasse 13, 49076, Osnabrück, Germany.
- Osnabrück University, Center of Cellular Nanoanalytic Osnabrück (CellNanOs), Barbarastrasse 11, 49076, Osnabrück, Germany.
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Indrawinata K, Argiropoulos P, Sugita S. Structural and functional understanding of disease-associated mutations in V-ATPase subunit a1 and other isoforms. Front Mol Neurosci 2023; 16:1135015. [PMID: 37465367 PMCID: PMC10352029 DOI: 10.3389/fnmol.2023.1135015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Accepted: 06/09/2023] [Indexed: 07/20/2023] Open
Abstract
The vacuolar-type ATPase (V-ATPase) is a multisubunit protein composed of the cytosolic adenosine triphosphate (ATP) hydrolysis catalyzing V1 complex, and the integral membrane complex, Vo, responsible for proton translocation. The largest subunit of the Vo complex, subunit a, enables proton translocation upon ATP hydrolysis, mediated by the cytosolic V1 complex. Four known subunit a isoforms (a1-a4) are expressed in different cellular locations. Subunit a1 (also known as Voa1), the neural isoform, is strongly expressed in neurons and is encoded by the ATP6V0A1 gene. Global knockout of this gene in mice causes embryonic lethality, whereas pyramidal neuron-specific knockout resulted in neuronal cell death with impaired spatial and learning memory. Recently reported, de novo and biallelic mutations of the human ATP6V0A1 impair autophagic and lysosomal activities, contributing to neuronal cell death in developmental and epileptic encephalopathies (DEE) and early onset progressive myoclonus epilepsy (PME). The de novo heterozygous R740Q mutation is the most recurrent variant reported in cases of DEE. Homology studies suggest R740 deprotonates protons from specific glutamic acid residues in subunit c, highlighting its importance to the overall V-ATPase function. In this paper, we discuss the structure and mechanism of the V-ATPase, emphasizing how mutations in subunit a1 can lead to lysosomal and autophagic dysfunction in neurodevelopmental disorders, and how mutations to the non-neural isoforms, a2-a4, can also lead to various genetic diseases. Given the growing discovery of disease-causing variants of V-ATPase subunit a and its function as a pump-based regulator of intracellular organelle pH, this multiprotein complex warrants further investigation.
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Affiliation(s)
- Karen Indrawinata
- Division of Translational and Experimental Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
| | - Peter Argiropoulos
- Division of Translational and Experimental Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
| | - Shuzo Sugita
- Division of Translational and Experimental Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON, Canada
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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5
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Wilkens S, Khan MM, Knight K, Oot R. Tender love and disassembly: How a TLDc domain protein breaks the V-ATPase. Bioessays 2023; 45:e2200251. [PMID: 37183929 PMCID: PMC10392918 DOI: 10.1002/bies.202200251] [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: 12/31/2022] [Revised: 04/13/2023] [Accepted: 05/03/2023] [Indexed: 05/16/2023]
Abstract
Vacuolar ATPases (V-ATPases, V1 Vo -ATPases) are rotary motor proton pumps that acidify intracellular compartments, and, when localized to the plasma membrane, the extracellular space. V-ATPase is regulated by a unique process referred to as reversible disassembly, wherein V1 -ATPase disengages from Vo proton channel in response to diverse environmental signals. Whereas the disassembly step of this process is ATP dependent, the (re)assembly step is not, but requires the action of a heterotrimeric chaperone referred to as the RAVE complex. Recently, an alternative pathway of holoenzyme disassembly was discovered that involves binding of Oxidation Resistance 1 (Oxr1p), a poorly characterized protein implicated in oxidative stress response. Unlike conventional reversible disassembly, which depends on enzyme activity, Oxr1p induced dissociation can occur in absence of ATP. Yeast Oxr1p belongs to the family of TLDc domain containing proteins that are conserved from yeast to mammals, and have been implicated in V-ATPase function in a variety of tissues. This brief perspective summarizes what we know about the molecular mechanisms governing both reversible (ATP dependent) and Oxr1p driven (ATP independent) V-ATPase dissociation into autoinhibited V1 and Vo subcomplexes.
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Affiliation(s)
- Stephan Wilkens
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY
| | - Md. Murad Khan
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY
| | - Kassidy Knight
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY
| | - Rebecca Oot
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY
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6
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Tuli F, Kane PM. The cytosolic N-terminal domain of V-ATPase a-subunits is a regulatory hub targeted by multiple signals. Front Mol Biosci 2023; 10:1168680. [PMID: 37398550 PMCID: PMC10313074 DOI: 10.3389/fmolb.2023.1168680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 06/05/2023] [Indexed: 07/04/2023] Open
Abstract
Vacuolar H+-ATPases (V-ATPases) acidify several organelles in all eukaryotic cells and export protons across the plasma membrane in a subset of cell types. V-ATPases are multisubunit enzymes consisting of a peripheral subcomplex, V1, that is exposed to the cytosol and an integral membrane subcomplex, Vo, that contains the proton pore. The Vo a-subunit is the largest membrane subunit and consists of two domains. The N-terminal domain of the a-subunit (aNT) interacts with several V1 and Vo subunits and serves to bridge the V1 and Vo subcomplexes, while the C-terminal domain contains eight transmembrane helices, two of which are directly involved in proton transport. Although there can be multiple isoforms of several V-ATPase subunits, the a-subunit is encoded by the largest number of isoforms in most organisms. For example, the human genome encodes four a-subunit isoforms that exhibit a tissue- and organelle-specific distribution. In the yeast S. cerevisiae, the two a-subunit isoforms, Golgi-enriched Stv1 and vacuolar Vph1, are the only V-ATPase subunit isoforms. Current structural information indicates that a-subunit isoforms adopt a similar backbone structure but sequence variations allow for specific interactions during trafficking and in response to cellular signals. V-ATPases are subject to several types of environmental regulation that serve to tune their activity to their cellular location and environmental demands. The position of the aNT domain in the complex makes it an ideal target for modulating V1-Vo interactions and regulating enzyme activity. The yeast a-subunit isoforms have served as a paradigm for dissecting interactions of regulatory inputs with subunit isoforms. Importantly, structures of yeast V-ATPases containing each a-subunit isoform are available. Chimeric a-subunits combining elements of Stv1NT and Vph1NT have provided insights into how regulatory inputs can be integrated to allow V-ATPases to support cell growth under different stress conditions. Although the function and distribution of the four mammalian a-subunit isoforms present additional complexity, it is clear that the aNT domains of these isoforms are also subject to multiple regulatory interactions. Regulatory mechanisms that target mammalian a-subunit isoforms, and specifically the aNT domains, will be described. Altered V-ATPase function is associated with multiple diseases in humans. The possibility of regulating V-ATPase subpopulations via their isoform-specific regulatory interactions are discussed.
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Affiliation(s)
| | - Patricia M. Kane
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, United States
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7
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Tan YZ, Abbas YM, Wu JZ, Wu D, Keon KA, Hesketh GG, Bueler SA, Gingras AC, Robinson CV, Grinstein S, Rubinstein JL. CryoEM of endogenous mammalian V-ATPase interacting with the TLDc protein mEAK-7. Life Sci Alliance 2022; 5:e202201527. [PMID: 35794005 PMCID: PMC9263379 DOI: 10.26508/lsa.202201527] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/17/2022] [Accepted: 06/21/2022] [Indexed: 12/18/2022] Open
Abstract
V-ATPases are rotary proton pumps that serve as signaling hubs with numerous protein binding partners. CryoEM with exhaustive focused classification allowed detection of endogenous proteins associated with porcine kidney V-ATPase. An extra C subunit was found in ∼3% of complexes, whereas ∼1.6% of complexes bound mEAK-7, a protein with proposed roles in dauer formation in nematodes and mTOR signaling in mammals. High-resolution cryoEM of porcine kidney V-ATPase with recombinant mEAK-7 showed that mEAK-7's TLDc domain interacts with V-ATPase's stator, whereas its C-terminal α helix binds V-ATPase's rotor. This crosslink would be expected to inhibit rotary catalysis. However, unlike the yeast TLDc protein Oxr1p, exogenous mEAK-7 does not inhibit V-ATPase and mEAK-7 overexpression in cells does not alter lysosomal or phagosomal pH. Instead, cryoEM suggests that the mEAK-7:V-ATPase interaction is disrupted by ATP-induced rotation of the rotor. Comparison of Oxr1p and mEAK-7 binding explains this difference. These results show that V-ATPase binding by TLDc domain proteins can lead to effects ranging from strong inhibition to formation of labile interactions that are sensitive to the enzyme's activity.
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Affiliation(s)
- Yong Zi Tan
- Molecular Medicine Program, The Hospital for Sick Children Research Institute, Toronto, Canada
| | - Yazan M Abbas
- Molecular Medicine Program, The Hospital for Sick Children Research Institute, Toronto, Canada
| | - Jing Ze Wu
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Canada
- Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Di Wu
- Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Kristine A Keon
- Molecular Medicine Program, The Hospital for Sick Children Research Institute, Toronto, Canada
| | - Geoffrey G Hesketh
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Canada
| | - Stephanie A Bueler
- Molecular Medicine Program, The Hospital for Sick Children Research Institute, Toronto, Canada
| | - Anne-Claude Gingras
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, Canada
| | - Carol V Robinson
- Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford, UK
| | - Sergio Grinstein
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Canada
- Department of Biochemistry, University of Toronto, Toronto, Canada
| | - John L Rubinstein
- Molecular Medicine Program, The Hospital for Sick Children Research Institute, Toronto, Canada
- Department of Biochemistry, University of Toronto, Toronto, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, Canada
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8
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Endosomal v-ATPase as a Sensor Determining Myocardial Substrate Preference. Metabolites 2022; 12:metabo12070579. [PMID: 35888703 PMCID: PMC9316095 DOI: 10.3390/metabo12070579] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 06/16/2022] [Accepted: 06/20/2022] [Indexed: 11/17/2022] Open
Abstract
The heart is a metabolically flexible omnivore that can utilize a variety of substrates for energy provision. To fulfill cardiac energy requirements, the healthy adult heart mainly uses long-chain fatty acids and glucose in a balanced manner, but when exposed to physiological or pathological stimuli, it can switch its substrate preference to alternative substrates such as amino acids (AAs) and ketone bodies. Using the failing heart as an example, upon stress, the fatty acid/glucose substrate balance is upset, resulting in an over-reliance on either fatty acids or glucose. A chronic fuel shift towards a single type of substrate is linked with cardiac dysfunction. Re-balancing myocardial substrate preference is suggested as an effective strategy to rescue the failing heart. In the last decade, we revealed that vacuolar-type H+-ATPase (v-ATPase) functions as a key regulator of myocardial substrate preference and, therefore, as a novel potential treatment approach for the failing heart. Fatty acids, glucose, and AAs selectively influence the assembly state of v-ATPase resulting in modulation of its proton-pumping activity. In this review, we summarize these novel insights on v-ATPase as an integrator of nutritional information. We also describe its exploitation as a therapeutic target with focus on supplementation of AA as a nutraceutical approach to fight lipid-induced insulin resistance and contractile dysfunction of the heart.
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9
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Vasanthakumar T, Keon KA, Bueler SA, Jaskolka MC, Rubinstein JL. Coordinated conformational changes in the V 1 complex during V-ATPase reversible dissociation. Nat Struct Mol Biol 2022; 29:430-439. [PMID: 35469063 DOI: 10.1038/s41594-022-00757-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 03/03/2022] [Indexed: 11/10/2022]
Abstract
Vacuolar-type ATPases (V-ATPases) are rotary enzymes that acidify intracellular compartments in eukaryotic cells. These multi-subunit complexes consist of a cytoplasmic V1 region that hydrolyzes ATP and a membrane-embedded VO region that transports protons. V-ATPase activity is regulated by reversible dissociation of the two regions, with the isolated V1 and VO complexes becoming autoinhibited on disassembly and subunit C subsequently detaching from V1. In yeast, assembly of the V1 and VO regions is mediated by the regulator of the ATPase of vacuoles and endosomes (RAVE) complex through an unknown mechanism. We used cryogenic-electron microscopy of yeast V-ATPase to determine structures of the intact enzyme, the dissociated but complete V1 complex and the V1 complex lacking subunit C. On separation, V1 undergoes a dramatic conformational rearrangement, with its rotational state becoming incompatible for reassembly with VO. Loss of subunit C allows V1 to match the rotational state of VO, suggesting how RAVE could reassemble V1 and VO by recruiting subunit C.
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Affiliation(s)
- Thamiya Vasanthakumar
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Biochemistry, The University of Toronto, Toronto, Ontario, Canada
| | - Kristine A Keon
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Medical Biophysics, The University of Toronto, Toronto, Ontario, Canada
| | - Stephanie A Bueler
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Michael C Jaskolka
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - John L Rubinstein
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, Ontario, Canada. .,Department of Biochemistry, The University of Toronto, Toronto, Ontario, Canada. .,Department of Medical Biophysics, The University of Toronto, Toronto, Ontario, Canada.
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10
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Maxson ME, Abbas YM, Wu JZ, Plumb JD, Grinstein S, Rubinstein JL. Detection and quantification of the vacuolar H+ATPase using the Legionella effector protein SidK. J Biophys Biochem Cytol 2022; 221:212963. [PMID: 35024770 PMCID: PMC8763849 DOI: 10.1083/jcb.202107174] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 12/14/2021] [Accepted: 12/21/2021] [Indexed: 12/11/2022] Open
Abstract
Acidification of secretory and endocytic organelles is required for proper receptor recycling, membrane traffic, protein degradation, and solute transport. Proton-pumping vacuolar H+ ATPases (V-ATPases) are responsible for this luminal acidification, which increases progressively as secretory and endocytic vesicles mature. An increasing density of V-ATPase complexes is thought to account for the gradual decrease in pH, but available reagents have not been sufficiently sensitive or specific to test this hypothesis. We introduce a new probe to localize and quantify V-ATPases. The probe is derived from SidK, a Legionella pneumophila effector protein that binds to the V-ATPase A subunit. We generated plasmids encoding fluorescent chimeras of SidK1-278, and labeled recombinant SidK1-278 with Alexa Fluor 568 to visualize and quantify V-ATPases with high specificity in live and fixed cells, respectively. We show that V-ATPases are acquired progressively during phagosome maturation, that they distribute in discrete membrane subdomains, and that their density in lysosomes depends on their subcellular localization.
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Affiliation(s)
- Michelle E Maxson
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Canada
| | - Yazan M Abbas
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Canada
| | - Jing Ze Wu
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - Jonathan D Plumb
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Canada
| | - Sergio Grinstein
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - John L Rubinstein
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
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11
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Wang C, Xiang Y, Qian D. Current progress in plant V-ATPase: From biochemical properties to physiological functions. JOURNAL OF PLANT PHYSIOLOGY 2021; 266:153525. [PMID: 34560396 DOI: 10.1016/j.jplph.2021.153525] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 09/12/2021] [Accepted: 09/12/2021] [Indexed: 06/13/2023]
Abstract
Vacuolar-type adenosine triphosphatase (V-ATPase, VHA) is a highly conserved, ATP-driven multisubunit proton pump that is widely distributed in all eukaryotic cells. V-ATPase consists of two domains formed by at least 13 different subunits, the membrane peripheral V1 domain responsible for ATP hydrolysis, and the membrane-integral V0 domain responsible for proton translocation. V-ATPase plays an essential role in energizing secondary active transport and is indispensable to plants. In addition to multiple stress responses, plant V-ATPase is also implicated in physiological processes such as growth, development, and morphogenesis. Based on the identification of distinct V-ATPase mutants and advances in luminal pH measurements in vivo, it has been revealed that this holoenzyme complex plays a pivotal role in pH homeostasis of the plant endomembrane system and endocytic and secretory trafficking. Here, we review recent progress in comprehending the biochemical properties and physiological functions of plant V-ATPase and explore the topics that require further elucidation.
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Affiliation(s)
- Chao Wang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yun Xiang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Dong Qian
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.
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12
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Tang Q, Liu M, Liu Y, Hwang RD, Zhang T, Wang J. NDST3 deacetylates α-tubulin and suppresses V-ATPase assembly and lysosomal acidification. EMBO J 2021; 40:e107204. [PMID: 34435379 PMCID: PMC8488563 DOI: 10.15252/embj.2020107204] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 07/18/2021] [Accepted: 07/20/2021] [Indexed: 12/18/2022] Open
Abstract
Lysosomes are key organelles maintaining cellular homeostasis in health and disease. Here, we report the identification of N‐deacetylase and N‐sulfotransferase 3 (NDST3) as a potent regulator of lysosomal functions through an unbiased genetic screen. NDST3 constitutes a new member of the histone deacetylase (HDAC) family and catalyzes the deacetylation of α‐tubulin. Loss of NDST3 promotes assembly of the V‐ATPase holoenzyme on the lysosomal membrane and thereby increases the acidification of the organelle. NDST3 is downregulated in tissues and cells from patients carrying the C9orf72 hexanucleotide repeat expansion linked to the neurodegenerative diseases amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Deficiency in C9orf72 decreases the level of NDST3, and downregulation of NDST3 exacerbates the proteotoxicity of poly‐dipeptides generated from the C9orf72 hexanucleotide repeats. These results demonstrate a previously unknown regulatory mechanism through which microtubule acetylation regulates lysosomal activities and suggest that NDST3 could be targeted to modulate microtubule and lysosomal functions in relevant diseases.
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Affiliation(s)
- Qing Tang
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.,Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Mingming Liu
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.,Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Yang Liu
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.,Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Ran-Der Hwang
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.,Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Tao Zhang
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.,Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Jiou Wang
- Department of Biochemistry and Molecular Biology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA.,Department of Neuroscience, School of Medicine, Johns Hopkins University, Baltimore, MD, USA
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Zubareva VM, Lapashina AS, Shugaeva TE, Litvin AV, Feniouk BA. Rotary Ion-Translocating ATPases/ATP Synthases: Diversity, Similarities, and Differences. BIOCHEMISTRY (MOSCOW) 2021; 85:1613-1630. [PMID: 33705299 DOI: 10.1134/s0006297920120135] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Ion-translocating ATPases and ATP synthases (F-, V-, A-type ATPases, and several P-type ATPases and ABC-transporters) catalyze ATP hydrolysis or ATP synthesis coupled with the ion transport across the membrane. F-, V-, and A-ATPases are protein nanomachines that combine transmembrane transport of protons or sodium ions with ATP synthesis/hydrolysis by means of a rotary mechanism. These enzymes are composed of two multisubunit subcomplexes that rotate relative to each other during catalysis. Rotary ATPases phosphorylate/dephosphorylate nucleotides directly, without the generation of phosphorylated protein intermediates. F-type ATPases are found in chloroplasts, mitochondria, most eubacteria, and in few archaea. V-type ATPases are eukaryotic enzymes present in a variety of cellular membranes, including the plasma membrane, vacuoles, late endosomes, and trans-Golgi cisternae. A-type ATPases are found in archaea and some eubacteria. F- and A-ATPases have two main functions: ATP synthesis powered by the proton motive force (pmf) or, in some prokaryotes, sodium-motive force (smf) and generation of the pmf or smf at the expense of ATP hydrolysis. In prokaryotes, both functions may be vitally important, depending on the environment and the presence of other enzymes capable of pmf or smf generation. In eukaryotes, the primary and the most crucial function of F-ATPases is ATP synthesis. Eukaryotic V-ATPases function exclusively as ATP-dependent proton pumps that generate pmf necessary for the transmembrane transport of ions and metabolites and are vitally important for pH regulation. This review describes the diversity of rotary ion-translocating ATPases from different organisms and compares the structural, functional, and regulatory features of these enzymes.
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Affiliation(s)
- V M Zubareva
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - A S Lapashina
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia.,Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - T E Shugaeva
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - A V Litvin
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - B A Feniouk
- Faculty of Bioengineering and Bioinformatics, Lomonosov Moscow State University, Moscow, 119991, Russia. .,Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
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14
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Wittig S, Ganzella M, Barth M, Kostmann S, Riedel D, Pérez-Lara Á, Jahn R, Schmidt C. Cross-linking mass spectrometry uncovers protein interactions and functional assemblies in synaptic vesicle membranes. Nat Commun 2021; 12:858. [PMID: 33558502 PMCID: PMC7870876 DOI: 10.1038/s41467-021-21102-w] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 12/18/2020] [Indexed: 02/08/2023] Open
Abstract
Synaptic vesicles are storage organelles for neurotransmitters. They pass through a trafficking cycle and fuse with the pre-synaptic membrane when an action potential arrives at the nerve terminal. While molecular components and biophysical parameters of synaptic vesicles have been determined, our knowledge on the protein interactions in their membranes is limited. Here, we apply cross-linking mass spectrometry to study interactions of synaptic vesicle proteins in an unbiased approach without the need for specific antibodies or detergent-solubilisation. Our large-scale analysis delivers a protein network of vesicle sub-populations and functional assemblies including an active and an inactive conformation of the vesicular ATPase complex as well as non-conventional arrangements of the luminal loops of SV2A, Synaptophysin and structurally related proteins. Based on this network, we specifically target Synaptobrevin-2, which connects with many proteins, in different approaches. Our results allow distinction of interactions caused by 'crowding' in the vesicle membrane from stable interaction modules.
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Affiliation(s)
- Sabine Wittig
- Interdisciplinary Research Centre HALOmem, Charles Tanford Protein Centre, Institute for Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Marcelo Ganzella
- Department for Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Marie Barth
- Interdisciplinary Research Centre HALOmem, Charles Tanford Protein Centre, Institute for Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Susann Kostmann
- Interdisciplinary Research Centre HALOmem, Charles Tanford Protein Centre, Institute for Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany
| | - Dietmar Riedel
- Department for Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Ángel Pérez-Lara
- Department for Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
- Department of Physical Chemistry, Faculty of Pharmacy, University of Granada, Granada, Spain
| | - Reinhard Jahn
- Department for Neurobiology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Carla Schmidt
- Interdisciplinary Research Centre HALOmem, Charles Tanford Protein Centre, Institute for Biochemistry and Biotechnology, Martin Luther University Halle-Wittenberg, Halle, Germany.
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15
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Lysosome as a Central Hub for Rewiring PH Homeostasis in Tumors. Cancers (Basel) 2020; 12:cancers12092437. [PMID: 32867178 PMCID: PMC7565471 DOI: 10.3390/cancers12092437] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/18/2020] [Accepted: 08/21/2020] [Indexed: 02/06/2023] Open
Abstract
Cancer cells generate large quantities of cytoplasmic protons as byproducts of aberrantly activated aerobic glycolysis and lactate fermentation. To avoid potentially detrimental acidification of the intracellular milieu, cancer cells activate multiple acid-removal pathways that promote cytosolic alkalization and extracellular acidification. Accumulating evidence suggests that in addition to the well-characterized ion pumps and exchangers in the plasma membrane, cancer cell lysosomes are also reprogrammed for this purpose. On the one hand, the increased expression and activity of the vacuolar-type H+-ATPase (V-ATPase) on the lysosomal limiting membrane combined with the larger volume of the lysosomal compartment increases the lysosomal proton storage capacity substantially. On the other hand, enhanced lysosome exocytosis enables the efficient release of lysosomal protons to the extracellular space. Together, these two steps dynamically drive proton flow from the cytosol to extracellular space. In this perspective, we provide mechanistic insight into how lysosomes contribute to the rewiring of pH homeostasis in cancer cells.
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16
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Collins MP, Forgac M. Regulation and function of V-ATPases in physiology and disease. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183341. [PMID: 32422136 DOI: 10.1016/j.bbamem.2020.183341] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/30/2020] [Accepted: 05/03/2020] [Indexed: 02/07/2023]
Abstract
The vacuolar H+-ATPases (V-ATPases) are essential, ATP-dependent proton pumps present in a variety of eukaryotic cellular membranes. Intracellularly, V-ATPase-dependent acidification functions in such processes as membrane traffic, protein degradation, autophagy and the coupled transport of small molecules. V-ATPases at the plasma membrane of certain specialized cells function in such processes as bone resorption, sperm maturation and urinary acidification. V-ATPases also function in disease processes such as pathogen entry and cancer cell invasiveness, while defects in V-ATPase genes are associated with disorders such as osteopetrosis, renal tubular acidosis and neurodegenerative diseases. This review highlights recent advances in our understanding of V-ATPase structure, mechanism, function and regulation, with an emphasis on the signaling pathways controlling V-ATPase assembly in mammalian cells. The role of V-ATPases in cancer and other human pathologies, and the prospects for therapeutic intervention, are also discussed.
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Affiliation(s)
- Michael P Collins
- Cell, Molecular and Developmental Biology, Tufts University Graduate School of Biomedical Sciences, United States of America
| | - Michael Forgac
- Cell, Molecular and Developmental Biology, Tufts University Graduate School of Biomedical Sciences, United States of America; Dept. of Developmental, Molecular and Chemical Biology, Tufts University School of Medicine, Boston, MA 02111, United States of America.
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17
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The Role of Secretory Pathways in Candida albicans Pathogenesis. J Fungi (Basel) 2020; 6:jof6010026. [PMID: 32102426 PMCID: PMC7151058 DOI: 10.3390/jof6010026] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Revised: 02/19/2020] [Accepted: 02/20/2020] [Indexed: 12/17/2022] Open
Abstract
Candida albicans is a fungus that is a commensal organism and a member of the normal human microbiota. It has the ability to transition into an opportunistic invasive pathogen. Attributes that support pathogenesis include secretion of virulence-associated proteins, hyphal formation, and biofilm formation. These processes are supported by secretion, as defined in the broad context of membrane trafficking. In this review, we examine the role of secretory pathways in Candida virulence, with a focus on the model opportunistic fungal pathogen, Candida albicans.
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18
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Jaskolka MC, Kane PM. Interaction between the yeast RAVE complex and Vph1-containing V o sectors is a central glucose-sensitive interaction required for V-ATPase reassembly. J Biol Chem 2020; 295:2259-2269. [PMID: 31941791 DOI: 10.1074/jbc.ra119.011522] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 01/02/2020] [Indexed: 12/12/2022] Open
Abstract
The yeast vacuolar H+-ATPase (V-ATPase) of budding yeast (Saccharomyces cerevisiae) is regulated by reversible disassembly. Disassembly inhibits V-ATPase activity under low-glucose conditions by releasing peripheral V1 subcomplexes from membrane-bound Vo subcomplexes. V-ATPase reassembly and reactivation requires intervention of the conserved regulator of H+-ATPase of vacuoles and endosomes (RAVE) complex, which binds to cytosolic V1 subcomplexes and assists reassembly with integral membrane Vo complexes. Consistent with its role, the RAVE complex itself is reversibly recruited to the vacuolar membrane by glucose, but the requirements for its recruitment are not understood. We demonstrate here that RAVE recruitment to the membrane does not require an interaction with V1 Glucose-dependent RAVE localization to the vacuolar membrane required only intact Vo complexes containing the Vph1 subunit, suggesting that the RAVE-Vo interaction is glucose-dependent. We identified a short conserved sequence in the center of the RAVE subunit Rav1 that is essential for the interaction with Vph1 in vivo and in vitro Mutations in this region resulted in the temperature- and pH-dependent growth phenotype characteristic of ravΔ mutants. However, this region did not account for glucose sensitivity of the Rav1-Vph1 interaction. We quantitated glucose-dependent localization of a GFP-tagged RAVE subunit to the vacuolar membrane in several mutants previously implicated in altering V-ATPase assembly state or glucose-induced assembly. RAVE localization did not correlate with V-ATPase assembly levels reported previously in these mutants, highlighting both the catalytic nature of RAVE's role in V-ATPase assembly and the likelihood of glucose signaling to RAVE independently of V1.
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Affiliation(s)
- Michael C Jaskolka
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - Patricia M Kane
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210.
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19
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Skruzny M, Pohl E, Abella M. FRET Microscopy in Yeast. BIOSENSORS 2019; 9:E122. [PMID: 31614546 PMCID: PMC6956097 DOI: 10.3390/bios9040122] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 09/19/2019] [Accepted: 09/30/2019] [Indexed: 02/06/2023]
Abstract
Förster resonance energy transfer (FRET) microscopy is a powerful fluorescence microscopy method to study the nanoscale organization of multiprotein assemblies in vivo. Moreover, many biochemical and biophysical processes can be followed by employing sophisticated FRET biosensors directly in living cells. Here, we summarize existing FRET experiments and biosensors applied in yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, two important models of fundamental biomedical research and efficient platforms for analyses of bioactive molecules. We aim to provide a practical guide on suitable FRET techniques, fluorescent proteins, and experimental setups available for successful FRET experiments in yeasts.
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Affiliation(s)
- Michal Skruzny
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany.
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), 35043 Marburg, Germany.
| | - Emma Pohl
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), 35043 Marburg, Germany
| | - Marc Abella
- Department of Systems and Synthetic Microbiology, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany
- LOEWE Center for Synthetic Microbiology (SYNMIKRO), 35043 Marburg, Germany
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20
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Abe M, Saito M, Tsukahara A, Shiokawa S, Ueno K, Shimamura H, Nagano M, Toshima JY, Toshima J. Functional complementation reveals that 9 of the 13 human V-ATPase subunits can functionally substitute for their yeast orthologs. J Biol Chem 2019; 294:8273-8285. [PMID: 30952699 DOI: 10.1074/jbc.ra118.006192] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 03/27/2019] [Indexed: 11/06/2022] Open
Abstract
Vacuolar-type H+-ATPase (V-ATPase) is a highly conserved proton pump responsible for acidification of intracellular organelles and potential drug target. It is a multisubunit complex comprising a cytoplasmic V1 domain responsible for ATP hydrolysis and a membrane-embedded Vo domain that contributes to proton translocation across the membrane. Saccharomyces cerevisiae V-ATPase is composed of 14 subunits, deletion of any one of which results in well-defined growth defects. As the structure of V-ATPase and the function of each subunit have been well-characterized in yeast, this organism has been recognized as a preferred model for studies of V-ATPases. In this study, to assess the functional relatedness of the yeast and human V-ATPase subunits, we investigated whether human V-ATPase subunits can complement calcium- or pH-sensitive growth, acidification of the vacuolar lumen, assembly of the V-ATPase complex, and protein sorting in yeast mutants lacking the equivalent yeast genes. These assessments revealed that 9 of the 13 human V-ATPase subunits can partially or fully complement the function of the corresponding yeast subunits. Importantly, sequence similarity was not necessarily correlated with functional complementation. We also found that besides all Vo domain subunits, the V1 F subunit is required for proper assembly of the Vo domain at the endoplasmic reticulum. Furthermore, the human H subunit fully restored the level of vacuolar acidification, but only partially rescued calcium-sensitive growth, suggesting a specific role of the H subunit in V-ATPase activity. These findings provide important insights into functional homologies between yeast and human V-ATPases.
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Affiliation(s)
- Michiko Abe
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijyuku, Katsushika-ku, Tokyo 125-8585
| | - Mayu Saito
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijyuku, Katsushika-ku, Tokyo 125-8585
| | - Ayana Tsukahara
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijyuku, Katsushika-ku, Tokyo 125-8585
| | - Shuka Shiokawa
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijyuku, Katsushika-ku, Tokyo 125-8585
| | - Kazuma Ueno
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijyuku, Katsushika-ku, Tokyo 125-8585
| | - Hiroki Shimamura
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijyuku, Katsushika-ku, Tokyo 125-8585
| | - Makoto Nagano
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijyuku, Katsushika-ku, Tokyo 125-8585
| | - Junko Y Toshima
- School of Health Science, Tokyo University of Technology, Ota-ku, Tokyo 144-8535, Japan.
| | - Jiro Toshima
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijyuku, Katsushika-ku, Tokyo 125-8585.
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21
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Sharma S, Oot RA, Khan MM, Wilkens S. Functional reconstitution of vacuolar H +-ATPase from V o proton channel and mutant V 1-ATPase provides insight into the mechanism of reversible disassembly. J Biol Chem 2019; 294:6439-6449. [PMID: 30792311 DOI: 10.1074/jbc.ra119.007577] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/10/2019] [Indexed: 12/12/2022] Open
Abstract
The vacuolar H+-ATPase (V-ATPase; V1Vo-ATPase) is an ATP-dependent proton pump that acidifies subcellular compartments in all eukaryotic organisms. V-ATPase activity is regulated by reversible disassembly into autoinhibited V1-ATPase and Vo proton channel subcomplexes, a process that is poorly understood on the molecular level. V-ATPase is a rotary motor, and recent structural analyses have revealed different rotary states for disassembled V1 and Vo, a mismatch that is likely responsible for their inability to reconstitute into holo V-ATPase in vitro Here, using the model organism Saccharomyces cerevisiae, we show that a key impediment for binding of V1 to Vo is the conformation of the inhibitory C-terminal domain of subunit H (HCT). Using biolayer interferometry and biochemical analyses of purified mutant V1-ATPase and Vo proton channel reconstituted into vacuolar lipid-containing nanodiscs, we further demonstrate that disruption of HCT's V1-binding site facilitates assembly of a functionally coupled and stable V1Vo-ATPase. Unlike WT, this mutant enzyme was resistant to MgATP hydrolysis-induced dissociation, further highlighting HCT's role in the mechanism of V-ATPase regulation. Our findings provide key insight into the molecular events underlying regulation of V-ATPase activity by reversible disassembly.
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Affiliation(s)
- Stuti Sharma
- From the Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - Rebecca A Oot
- From the Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - Md Murad Khan
- From the Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - Stephan Wilkens
- From the Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
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22
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Hayek SR, Rane HS, Parra KJ. Reciprocal Regulation of V-ATPase and Glycolytic Pathway Elements in Health and Disease. Front Physiol 2019; 10:127. [PMID: 30828305 PMCID: PMC6384264 DOI: 10.3389/fphys.2019.00127] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 01/31/2019] [Indexed: 12/24/2022] Open
Abstract
The ability of cells to adapt to fluctuations in glucose availability is crucial for their survival and involves the vacuolar proton-translocating ATPase (V-ATPase), a proton pump found in all eukaryotes. V-ATPase hydrolyzes ATP via its V1 domain and uses the energy released to transport protons across membranes via its Vo domain. This activity is critical for pH homeostasis and generation of a membrane potential that drives cellular metabolism. A number of stimuli have been reported to alter V-ATPase assembly in yeast and higher eukaryotes. Glucose flux is one of the strongest and best-characterized regulators of V-ATPase; this review highlights current models explaining how glycolysis and V-ATPase are coordinated in both the Saccharomyces cerevisiae model fungus and in mammalian systems. Glucose-dependent assembly and trafficking of V-ATPase, V-ATPase-dependent modulations in glycolysis, and the recent discovery that glucose signaling through V-ATPase acts as a molecular switch to dictate anabolic versus catabolic metabolism are discussed. Notably, metabolic plasticity and altered glycolytic flux are critical drivers of numerous human pathologies, and the expression and activity of V-ATPase is often altered in disease states or can be pharmacologically manipulated as treatment. This overview will specifically discuss connections between V-ATPase and glycolysis in cancer.
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Affiliation(s)
- Summer R Hayek
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Hallie S Rane
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Karlett J Parra
- Department of Biochemistry and Molecular Biology, University of New Mexico Health Sciences Center, Albuquerque, NM, United States
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23
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Interaction of mammalian and plant H +/sucrose transporters with 14-3-3 proteins. Biochem J 2018; 475:3239-3254. [PMID: 30237153 DOI: 10.1042/bcj20180293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 08/22/2018] [Accepted: 09/18/2018] [Indexed: 01/08/2023]
Abstract
The solute carrier 45 family (SLC45) was defined in the course of the Human Genome Project and consists of four members, A1-A4, which show only 20-30% identity of amino acid sequences among each other. All these members exhibit an identity of ∼20% to plant H+/sucrose cotransporters. Recently, we expressed members of the murine SLC45 family in yeast cells and demonstrated that they are, like their plant counterparts, H+/sucrose cotransporters. In contrast with the plant proteins, SLC45 transporters recognise also the monosaccharides glucose and fructose as physiological substrates and seem to be involved in alternative sugar supply as well as in osmoregulation of several mammalian tissues. In the present study, we provide novel insights into the regulation of SLC45 transporters. By screening for interaction partners, we found a 14-3-3 protein as a promising candidate for control of transport activity. Indeed, co-expression of the gamma isoform of murine 14-3-3 protein in yeast and Xenopus oocytes led to a significant decrease in transport rates of the murine SLC45 transporters as well as of the plant H+/sucrose transporter Sut1.
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24
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Colina-Tenorio L, Dautant A, Miranda-Astudillo H, Giraud MF, González-Halphen D. The Peripheral Stalk of Rotary ATPases. Front Physiol 2018; 9:1243. [PMID: 30233414 PMCID: PMC6131620 DOI: 10.3389/fphys.2018.01243] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/16/2018] [Indexed: 12/18/2022] Open
Abstract
Rotary ATPases are a family of enzymes that are thought of as molecular nanomotors and are classified in three types: F, A, and V-type ATPases. Two members (F and A-type) can synthesize and hydrolyze ATP, depending on the energetic needs of the cell, while the V-type enzyme exhibits only a hydrolytic activity. The overall architecture of all these enzymes is conserved and three main sectors are distinguished: a catalytic core, a rotor and a stator or peripheral stalk. The peripheral stalks of the A and V-types are highly conserved in both structure and function, however, the F-type peripheral stalks have divergent structures. Furthermore, the peripheral stalk has other roles beyond its stator function, as evidenced by several biochemical and recent structural studies. This review describes the information regarding the organization of the peripheral stalk components of F, A, and V-ATPases, highlighting the key differences between the studied enzymes, as well as the different processes in which the structure is involved.
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Affiliation(s)
- Lilia Colina-Tenorio
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Alain Dautant
- CNRS, UMR5095, IBGC, Bordeaux, France.,Energy Transducing Systems and Mitochondrial Morphology, Université de Bordeaux, Bordeaux, France
| | - Héctor Miranda-Astudillo
- Genetics and Physiology of Microalgae, InBios, PhytoSYSTEMS, University of Liège, Liège, Belgium
| | - Marie-France Giraud
- CNRS, UMR5095, IBGC, Bordeaux, France.,Energy Transducing Systems and Mitochondrial Morphology, Université de Bordeaux, Bordeaux, France
| | - Diego González-Halphen
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Mexico City, Mexico
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25
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Harrison MA, Muench SP. The Vacuolar ATPase - A Nano-scale Motor That Drives Cell Biology. Subcell Biochem 2018; 87:409-459. [PMID: 29464568 DOI: 10.1007/978-981-10-7757-9_14] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The vacuolar H+-ATPase (V-ATPase) is a ~1 MDa membrane protein complex that couples the hydrolysis of cytosolic ATP to the transmembrane movement of protons. In essentially all eukaryotic cells, this acid pumping function plays critical roles in the acidification of endosomal/lysosomal compartments and hence in transport, recycling and degradative pathways. It is also important in acid extrusion across the plasma membrane of some cells, contributing to homeostatic control of cytoplasmic pH and maintenance of appropriate extracellular acidity. The complex, assembled from up to 30 individual polypeptides, operates as a molecular motor with rotary mechanics. Historically, structural inferences about the eukaryotic V-ATPase and its subunits have been made by comparison to the structures of bacterial homologues. However, more recently, we have developed a much better understanding of the complete structure of the eukaryotic complex, in particular through advances in cryo-electron microscopy. This chapter explores these recent developments, and examines what they now reveal about the catalytic mechanism of this essential proton pump and how its activity might be regulated in response to cellular signals.
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Affiliation(s)
- Michael A Harrison
- School of Biomedical Sciences, Faculty of Biological Sciences, The University of Leeds, Leeds, UK.
| | - Steven P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences, The University of Leeds, Leeds, UK
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26
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Bodzęta A, Kahms M, Klingauf J. The Presynaptic v-ATPase Reversibly Disassembles and Thereby Modulates Exocytosis but Is Not Part of the Fusion Machinery. Cell Rep 2017; 20:1348-1359. [DOI: 10.1016/j.celrep.2017.07.040] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 06/23/2017] [Accepted: 07/14/2017] [Indexed: 11/15/2022] Open
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27
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Rotating with the brakes on and other unresolved features of the vacuolar ATPase. Biochem Soc Trans 2017; 44:851-5. [PMID: 27284051 PMCID: PMC4900747 DOI: 10.1042/bst20160043] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Indexed: 12/31/2022]
Abstract
The rotary ATPase family comprises the ATP synthase (F-ATPase), vacuolar ATPase (V-ATPase) and archaeal ATPase (A-ATPase). These either predominantly utilize a proton gradient for ATP synthesis or use ATP to produce a proton gradient, driving secondary transport and acidifying organelles. With advances in EM has come a significant increase in our understanding of the rotary ATPase family. Following the sub nm resolution reconstructions of both the F- and V-ATPases, the secondary structure organization of the elusive subunit a has now been resolved, revealing a novel helical arrangement. Despite these significant developments in our understanding of the rotary ATPases, there are still a number of unresolved questions about the mechanism, regulation and overall architecture, which this mini-review aims to highlight and discuss.
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Oot RA, Couoh-Cardel S, Sharma S, Stam NJ, Wilkens S. Breaking up and making up: The secret life of the vacuolar H + -ATPase. Protein Sci 2017; 26:896-909. [PMID: 28247968 DOI: 10.1002/pro.3147] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 02/21/2017] [Indexed: 01/24/2023]
Abstract
The vacuolar ATPase (V-ATPase; V1 Vo -ATPase) is a large multisubunit proton pump found in the endomembrane system of all eukaryotic cells where it acidifies the lumen of subcellular organelles including lysosomes, endosomes, the Golgi apparatus, and clathrin-coated vesicles. V-ATPase function is essential for pH and ion homeostasis, protein trafficking, endocytosis, mechanistic target of rapamycin (mTOR), and Notch signaling, as well as hormone secretion and neurotransmitter release. V-ATPase can also be found in the plasma membrane of polarized animal cells where its proton pumping function is involved in bone remodeling, urine acidification, and sperm maturation. Aberrant (hypo or hyper) activity has been associated with numerous human diseases and the V-ATPase has therefore been recognized as a potential drug target. Recent progress with moderate to high-resolution structure determination by cryo electron microscopy and X-ray crystallography together with sophisticated single-molecule and biochemical experiments have provided a detailed picture of the structure and unique mode of regulation of the V-ATPase. This review summarizes the recent advances, focusing on the structural and biophysical aspects of the field.
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Affiliation(s)
- Rebecca A Oot
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, 13210
| | - Sergio Couoh-Cardel
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, 13210
| | - Stuti Sharma
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, 13210
| | - Nicholas J Stam
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, 13210
| | - Stephan Wilkens
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, 13210
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Chan CY, Dominguez D, Parra KJ. Regulation of Vacuolar H+-ATPase (V-ATPase) Reassembly by Glycolysis Flow in 6-Phosphofructo-1-kinase (PFK-1)-deficient Yeast Cells. J Biol Chem 2016; 291:15820-9. [PMID: 27226568 DOI: 10.1074/jbc.m116.717488] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Indexed: 01/21/2023] Open
Abstract
Yeast 6-phosphofructo-1-kinase (PFK-1) has two subunits, Pfk1p and Pfk2p. Deletion of Pfk2p alters glucose-dependent V-ATPase reassembly and vacuolar acidification (Chan, C. Y., and Parra, K. J. (2014) Yeast phosphofructokinase-1 subunit Pfk2p is necessary for pH homeostasis and glucose-dependent vacuolar ATPase reassembly. J. Biol. Chem. 289, 19448-19457). This study capitalized on the mechanisms suppressing vacuolar H(+)-ATPase (V-ATPase) in pfk2Δ to gain new knowledge of the mechanisms underlying glucose-dependent V-ATPase regulation. Because V-ATPase is fully assembled in pfk2Δ, and glycolysis partially suppressed at steady state, we manipulated glycolysis and assessed its direct involvement on V-ATPase function. At steady state, the ratio of proton transport to ATP hydrolysis increased 24% after increasing the glucose concentration from 2% to 4% to enhance the glycolysis flow in pfk2Δ. Tighter coupling restored vacuolar pH when glucose was abundant and glycolysis operated below capacity. After readdition of glucose to glucose-deprived cells, glucose-dependent V1Vo reassembly was proportional to the glycolysis flow. Readdition of 2% glucose to pfk2Δ cells, which restored 62% of ethanol concentration, led to equivalent 60% V1Vo reassembly levels. Steady-state level of assembly (100% reassembly) was reached at 4% glucose when glycolysis reached a threshold in pfk2Δ (≥40% the wild-type flow). At 4% glucose, the level of Pfk1p co-immunoprecipitated with V-ATPase decreased 58% in pfk2Δ, suggesting that Pfk1p binding to V-ATPase may be inhibitory in the mutant. We concluded that V-ATPase activity at steady state and V-ATPase reassembly after readdition of glucose to glucose-deprived cells are controlled by the glycolysis flow. We propose a new mechanism by which glucose regulates V-ATPase catalytic activity that occurs at steady state without changing V1Vo assembly.
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Affiliation(s)
- Chun-Yuan Chan
- From the Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
| | - Dennis Dominguez
- From the Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
| | - Karlett J Parra
- From the Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico Health Sciences Center, Albuquerque, New Mexico 87131
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Cotter K, Stransky L, McGuire C, Forgac M. Recent Insights into the Structure, Regulation, and Function of the V-ATPases. Trends Biochem Sci 2016; 40:611-622. [PMID: 26410601 DOI: 10.1016/j.tibs.2015.08.005] [Citation(s) in RCA: 211] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 08/06/2015] [Accepted: 08/07/2015] [Indexed: 10/23/2022]
Abstract
The vacuolar (H(+))-ATPases (V-ATPases) are ATP-dependent proton pumps that acidify intracellular compartments and are also present at the plasma membrane. They function in such processes as membrane traffic, protein degradation, virus and toxin entry, bone resorption, pH homeostasis, and tumor cell invasion. V-ATPases are large multisubunit complexes, composed of an ATP-hydrolytic domain (V1) and a proton translocation domain (V0), and operate by a rotary mechanism. This review focuses on recent insights into their structure and mechanism, the mechanisms that regulate V-ATPase activity (particularly regulated assembly and trafficking), and the role of V-ATPases in processes such as cell signaling and cancer. These developments have highlighted the potential of V-ATPases as a therapeutic target in a variety of human diseases.
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Affiliation(s)
- Kristina Cotter
- Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Laura Stransky
- Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Christina McGuire
- Program in Biochemistry, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - Michael Forgac
- Program in Cellular and Molecular Physiology, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA; Program in Biochemistry, Sackler School of Graduate Biomedical Sciences, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA; Department of Developmental, Molecular, and Chemical Biology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA.
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Tognon E, Kobia F, Busi I, Fumagalli A, De Masi F, Vaccari T. Control of lysosomal biogenesis and Notch-dependent tissue patterning by components of the TFEB-V-ATPase axis in Drosophila melanogaster. Autophagy 2016; 12:499-514. [PMID: 26727288 PMCID: PMC4836007 DOI: 10.1080/15548627.2015.1134080] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022] Open
Abstract
In vertebrates, TFEB (transcription factor EB) and MITF (microphthalmia-associated transcription factor) family of basic Helix-Loop-Helix (bHLH) transcription factors regulates both lysosomal function and organ development. However, it is not clear whether these 2 processes are interconnected. Here, we show that Mitf, the single TFEB and MITF ortholog in Drosophila, controls expression of vacuolar-type H(+)-ATPase pump (V-ATPase) subunits. Remarkably, we also find that expression of Vha16-1 and Vha13, encoding 2 key components of V-ATPase, is patterned in the wing imaginal disc. In particular, Vha16-1 expression follows differentiation of proneural regions of the disc. These regions, which will form sensory organs in the adult, appear to possess a distinctive endolysosomal compartment and Notch (N) localization. Modulation of Mitf activity in the disc in vivo alters endolysosomal function and disrupts proneural patterning. Similar to our findings in Drosophila, in human breast epithelial cells we observe that impairment of the Vha16-1 human ortholog ATP6V0C changes the size and function of the endolysosomal compartment and that depletion of TFEB reduces ligand-independent N signaling activity. Our data suggest that lysosomal-associated functions regulated by the TFEB-V-ATPase axis might play a conserved role in shaping cell fate.
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Affiliation(s)
- Emiliana Tognon
- a IFOM - FIRC Institute of Molecular Oncology , Milan , Italy
| | - Francis Kobia
- a IFOM - FIRC Institute of Molecular Oncology , Milan , Italy
| | - Ilaria Busi
- a IFOM - FIRC Institute of Molecular Oncology , Milan , Italy
| | | | - Federico De Masi
- b Center for Biological Sequence Analysis, Institute for Systems Biology, Technical University of Denmark , Lyngby , Denmark
| | - Thomas Vaccari
- a IFOM - FIRC Institute of Molecular Oncology , Milan , Italy
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Abstract
Despite diverse and changing extracellular environments, fungi maintain a relatively constant cytosolic pH and numerous organelles of distinct lumenal pH. Key players in fungal pH control are V-ATPases and the P-type proton pump Pma1. These two proton pumps act in concert with a large array of other transporters and are highly regulated. The activities of Pma1 and the V-ATPase are coordinated under some conditions, suggesting that pH in the cytosol and organelles is not controlled independently. Genomic studies, particularly in the highly tractable S. cerevisiae, are beginning to provide a systems-level view of pH control, including transcriptional responses to acid or alkaline ambient pH and definition of the full set of regulators required to maintain pH homeostasis. Genetically encoded pH sensors have provided new insights into localized mechanisms of pH control, as well as highlighting the dynamic nature of pH responses to the extracellular environment. Recent studies indicate that cellular pH plays a genuine signaling role that connects nutrient availability and growth rate through a number of mechanisms. Many of the pH control mechanisms found in S. cerevisiae are shared with other fungi, with adaptations for their individual physiological contexts. Fungi deploy certain proton transport and pH control mechanisms not shared with other eukaryotes; these regulators of cellular pH are potential antifungal targets. This review describes current and emerging knowledge proton transport and pH control mechanisms in S. cerevisiae and briefly discusses how these mechanisms vary among fungi.
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Smardon AM, Nasab ND, Tarsio M, Diakov TT, Kane PM. Molecular Interactions and Cellular Itinerary of the Yeast RAVE (Regulator of the H+-ATPase of Vacuolar and Endosomal Membranes) Complex. J Biol Chem 2015; 290:27511-23. [PMID: 26405040 DOI: 10.1074/jbc.m115.667634] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Indexed: 12/11/2022] Open
Abstract
The RAVE complex (regulator of the H(+)-ATPase of vacuolar and endosomal membranes) is required for biosynthetic assembly and glucose-stimulated reassembly of the yeast vacuolar H(+)-ATPase (V-ATPase). Yeast RAVE contains three subunits: Rav1, Rav2, and Skp1. Rav1 is the largest subunit, and it binds Rav2 and Skp1 of RAVE; the E, G, and C subunits of the V-ATPase peripheral V1 sector; and Vph1 of the membrane Vo sector. We identified Rav1 regions required for interaction with its binding partners through deletion analysis, co-immunoprecipitation, two-hybrid assay, and pulldown assays with expressed proteins. We find that Skp1 binding requires sequences near the C terminus of Rav1, V1 subunits E and C bind to a conserved region in the C-terminal half of Rav1, and the cytosolic domain of Vph1 binds near the junction of the Rav1 N- and C-terminal halves. In contrast, Rav2 binds to the N-terminal domain of Rav1, which can be modeled as a double β-propeller. Only the V1 C subunit binds to both Rav1 and Rav2. Using GFP-tagged RAVE subunits in vivo, we demonstrate glucose-dependent association of RAVE with the vacuolar membrane, consistent with its role in glucose-dependent V-ATPase assembly. It is known that V1 subunit C localizes to the V1-Vo interface in assembled V-ATPase complexes and is important in regulated disassembly of V-ATPases. We propose that RAVE cycles between cytosol and vacuolar membrane in a glucose-dependent manner, positioning V1 and V0 subcomplexes and orienting the V1 C subunit to promote assembly.
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Affiliation(s)
- Anne M Smardon
- From the Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - Negin Dehdar Nasab
- From the Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - Maureen Tarsio
- From the Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - Theodore T Diakov
- From the Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
| | - Patricia M Kane
- From the Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York 13210
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Deranieh RM, Shi Y, Tarsio M, Chen Y, McCaffery JM, Kane PM, Greenberg ML. Perturbation of the Vacuolar ATPase: A NOVEL CONSEQUENCE OF INOSITOL DEPLETION. J Biol Chem 2015; 290:27460-72. [PMID: 26324718 DOI: 10.1074/jbc.m115.683706] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Indexed: 11/06/2022] Open
Abstract
Depletion of inositol has profound effects on cell function and has been implicated in the therapeutic effects of drugs used to treat epilepsy and bipolar disorder. We have previously shown that the anticonvulsant drug valproate (VPA) depletes inositol by inhibiting myo-inositol-3-phosphate synthase, the enzyme that catalyzes the first and rate-limiting step of inositol biosynthesis. To elucidate the cellular consequences of inositol depletion, we screened the yeast deletion collection for VPA-sensitive mutants and identified mutants in vacuolar sorting and the vacuolar ATPase (V-ATPase). Inositol depletion caused by starvation of ino1Δ cells perturbed the vacuolar structure and decreased V-ATPase activity and proton pumping in isolated vacuolar vesicles. VPA compromised the dynamics of phosphatidylinositol 3,5-bisphosphate (PI3,5P2) and greatly reduced V-ATPase proton transport in inositol-deprived wild-type cells. Osmotic stress, known to increase PI3,5P2 levels, did not restore PI3,5P2 homeostasis nor did it induce vacuolar fragmentation in VPA-treated cells, suggesting that perturbation of the V-ATPase is a consequence of altered PI3,5P2 homeostasis under inositol-limiting conditions. This study is the first to demonstrate that inositol depletion caused by starvation of an inositol synthesis mutant or by the inositol-depleting drug VPA leads to perturbation of the V-ATPase.
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Affiliation(s)
- Rania M Deranieh
- From the Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202
| | - Yihui Shi
- From the Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202
| | - Maureen Tarsio
- the Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210, and
| | - Yan Chen
- From the Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202
| | - J Michael McCaffery
- the Integrated Imaging Center, Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218
| | - Patricia M Kane
- the Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210, and
| | - Miriam L Greenberg
- From the Department of Biological Sciences, Wayne State University, Detroit, Michigan 48202,
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35
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Maxson ME, Grinstein S. The vacuolar-type H⁺-ATPase at a glance - more than a proton pump. J Cell Sci 2015; 127:4987-93. [PMID: 25453113 DOI: 10.1242/jcs.158550] [Citation(s) in RCA: 172] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The vacuolar H(+)-ATPase (V-ATPase) has long been appreciated to function as an electrogenic H(+) pump. By altering the pH of intracellular compartments, the V-ATPase dictates enzyme activity, governs the dissociation of ligands from receptors and promotes the coupled transport of substrates across membranes, a role often aided by the generation of a transmembrane electrical potential. In tissues where the V-ATPase is expressed at the plasma membrane, it can serve to acidify the extracellular microenvironment. More recently, however, the V-ATPase has been implicated in a bewildering variety of additional roles that seem independent of its ability to translocate H(+). These non-canonical functions, which include fusogenicity, cytoskeletal tethering and metabolic sensing, are described in this Cell Science at a Glance article and accompanying poster, together with a brief overview of the conventional functions of the V-ATPase.
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Affiliation(s)
- Michelle E Maxson
- Program in Cell Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, M5G 0A4, Canada
| | - Sergio Grinstein
- Program in Cell Biology, Hospital for Sick Children, 686 Bay Street, Toronto, ON, M5G 0A4, Canada Keenan Research Centre of the Li Ka Shing Knowledge Institute, St. Michael's Hospital, 290 Victoria Street, Toronto, ON, M5C 1N8, Canada
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36
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Balakrishna AM, Manimekalai MSS, Grüber G. Protein-protein interactions within the ensemble, eukaryotic V-ATPase, and its concerted interactions with cellular machineries. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2015; 119:84-93. [PMID: 26033199 DOI: 10.1016/j.pbiomolbio.2015.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/27/2015] [Accepted: 05/28/2015] [Indexed: 11/27/2022]
Abstract
The V1VO-ATPase (V-ATPase) is the important proton-pump in eukaryotic cells, responsible for pH-homeostasis, pH-sensing and amino acid sensing, and therefore essential for cell growths and metabolism. ATP-cleavage in the catalytic A3B3-hexamer of V1 has to be communicated via several so-called central and peripheral stalk units to the proton-pumping VO-part, which is membrane-embedded. A unique feature of V1VO-ATPase regulation is its reversible disassembly of the V1 and VO domain. Actin provides a network to hold the V1 in proximity to the VO, enabling effective V1VO-assembly to occur. Besides binding to actin, the 14-subunit V-ATPase interacts with multi-subunit machineries to form cellular sensors, which regulate the pH in cellular compartments or amino acid signaling in lysosomes. Here we describe a variety of subunit-subunit interactions within the V-ATPase enzyme during catalysis and its protein-protein assembling with key cellular machineries, essential for cellular function.
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Affiliation(s)
- Asha Manikkoth Balakrishna
- Nanyang Technological University, Division of Structural Biology and Biochemistry, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Malathy Sony Subramanian Manimekalai
- Nanyang Technological University, Division of Structural Biology and Biochemistry, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
| | - Gerhard Grüber
- Nanyang Technological University, Division of Structural Biology and Biochemistry, School of Biological Sciences, 60 Nanyang Drive, Singapore 637551, Republic of Singapore.
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Rawson S, Phillips C, Huss M, Tiburcy F, Wieczorek H, Trinick J, Harrison MA, Muench SP. Structure of the vacuolar H+-ATPase rotary motor reveals new mechanistic insights. Structure 2015; 23:461-471. [PMID: 25661654 PMCID: PMC4353692 DOI: 10.1016/j.str.2014.12.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Revised: 12/05/2014] [Accepted: 12/06/2014] [Indexed: 01/08/2023]
Abstract
Vacuolar H(+)-ATPases are multisubunit complexes that operate with rotary mechanics and are essential for membrane proton transport throughout eukaryotes. Here we report a ∼ 1 nm resolution reconstruction of a V-ATPase in a different conformational state from that previously reported for a lower-resolution yeast model. The stator network of the V-ATPase (and by implication that of other rotary ATPases) does not change conformation in different catalytic states, and hence must be relatively rigid. We also demonstrate that a conserved bearing in the catalytic domain is electrostatic, contributing to the extraordinarily high efficiency of rotary ATPases. Analysis of the rotor axle/membrane pump interface suggests how rotary ATPases accommodate different c ring stoichiometries while maintaining high efficiency. The model provides evidence for a half channel in the proton pump, supporting theoretical models of ion translocation. Our refined model therefore provides new insights into the structure and mechanics of the V-ATPases.
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Affiliation(s)
- Shaun Rawson
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Clair Phillips
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Markus Huss
- Abteilung Tierphysiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, 49069 Osnabrück, Germany
| | - Felix Tiburcy
- Abteilung Tierphysiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, 49069 Osnabrück, Germany
| | - Helmut Wieczorek
- Abteilung Tierphysiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, 49069 Osnabrück, Germany
| | - John Trinick
- School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Michael A Harrison
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Stephen P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK.
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Richardson RA, Papachristos K, Read DJ, Harlen OG, Harrison M, Paci E, Muench SP, Harris SA. Understanding the apparent stator-rotor connections in the rotary ATPase family using coarse-grained computer modeling. Proteins 2014; 82:3298-311. [PMID: 25174610 DOI: 10.1002/prot.24680] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 07/14/2014] [Accepted: 08/06/2014] [Indexed: 11/12/2022]
Abstract
Advances in structural biology, such as cryo-electron microscopy (cryo-EM) have allowed for a number of sophisticated protein complexes to be characterized. However, often only a static snapshot of a protein complex is visualized despite the fact that conformational change is frequently inherent to biological function, as is the case for molecular motors. Computer simulations provide valuable insights into the different conformations available to a particular system that are not accessible using conventional structural techniques. For larger proteins and protein complexes, where a fully atomistic description would be computationally prohibitive, coarse-grained simulation techniques such as Elastic Network Modeling (ENM) are often employed, whereby each atom or group of atoms is linked by a set of springs whose properties can be customized according to the system of interest. Here we compare ENM with a recently proposed continuum model known as Fluctuating Finite Element Analysis (FFEA), which represents the biomolecule as a viscoelastic solid subject to thermal fluctuations. These two complementary computational techniques are used to answer a critical question in the rotary ATPase family; implicit within these motors is the need for a rotor axle and proton pump to rotate freely of the motor domain and stator structures. However, current single particle cryo-EM reconstructions have shown an apparent connection between the stators and rotor axle or pump region, hindering rotation. Both modeling approaches show a possible role for this connection and how it would significantly constrain the mobility of the rotary ATPase family.
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Affiliation(s)
- Robin A Richardson
- School of Physics and Astronomy, University of Leeds, Leeds, United Kingdom
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