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Oot RA, Wilkens S. Human V-ATPase function is positively and negatively regulated by TLDc proteins. Structure 2024; 32:989-1000.e6. [PMID: 38593795 PMCID: PMC11246223 DOI: 10.1016/j.str.2024.03.009] [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: 11/09/2023] [Revised: 02/23/2024] [Accepted: 03/13/2024] [Indexed: 04/11/2024]
Abstract
Proteins that contain a highly conserved TLDc domain (Tre2/Bub2/Cdc16 LysM domain catalytic) offer protection against oxidative stress and are widely implicated in neurological health and disease. How this family of proteins exerts their function, however, is poorly understood. We have recently found that the yeast TLDc protein, Oxr1p, inhibits the proton pumping vacuolar ATPase (V-ATPase) by inducing disassembly of the pump. While loss of TLDc protein function in mammals shares disease phenotypes with V-ATPase defects, whether TLDc proteins impact human V-ATPase activity directly is unclear. Here we examine the effects of five human TLDc proteins, TLDC2, NCOA7, OXR1, TBC1D24, and mEAK7 on the activity of the human V-ATPase. We find that while TLDC2, TBC1D24, and the TLDc domains of OXR1 and NCOA7 inhibit V-ATPase by inducing enzyme disassembly, mEAK7 activates the pump. The data thus shed new light both on mammalian TLDc protein function and V-ATPase regulation.
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Affiliation(s)
- Rebecca A Oot
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA.
| | - Stephan Wilkens
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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2
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Khan MM, Wilkens S. Molecular mechanism of Oxr1p mediated disassembly of yeast V-ATPase. EMBO Rep 2024; 25:2323-2347. [PMID: 38565737 PMCID: PMC11094088 DOI: 10.1038/s44319-024-00126-5] [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: 12/03/2023] [Revised: 03/07/2024] [Accepted: 03/09/2024] [Indexed: 04/04/2024] Open
Abstract
The eukaryotic vacuolar H+-ATPase (V-ATPase) is regulated by reversible disassembly into autoinhibited V1-ATPase and Vo proton channel subcomplexes. We recently reported that the TLDc protein Oxr1p induces V-ATPase disassembly in vitro. Whether and how Oxr1p is involved in enzyme disassembly in vivo, however, is not known. Here, using yeast genetics and fluorescence microscopy, we show that Oxr1p is essential for efficient V-ATPase disassembly in the cell. Supporting biochemical and biophysical in vitro experiments show that whereas Oxr1p-driven holoenzyme disassembly can occur in the absence of nucleotides, the presence of ATP greatly accelerates the process. ATP hydrolysis is needed, however, for subsequent release of Oxr1p so that the free V1 can adopt the autoinhibited conformation. Overall, our study unravels the molecular mechanism of Oxr1p-induced disassembly that occurs in vivo as part of the canonical V-ATPase regulation by reversible disassembly.
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Affiliation(s)
- Md Murad Khan
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA
| | - Stephan Wilkens
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, 13210, USA.
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Dreyer A, Lenz C, Groß U, Bohne W, Zautner AE. Comparative analysis of proteomic adaptations in Enterococcus faecalis and Enterococcus faecium after long term bile acid exposure. BMC Microbiol 2024; 24:110. [PMID: 38570789 PMCID: PMC10988882 DOI: 10.1186/s12866-024-03253-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Accepted: 03/07/2024] [Indexed: 04/05/2024] Open
Abstract
BACKGROUND All gastrointestinal pathogens, including Enterococcus faecalis and Enterococcus faecium, undergo adaptation processes during colonization and infection. In this study, we investigated by data-independent acquisition mass spectrometry (DIA-MS) two crucial adaptations of these two Enterococcus species at the proteome level. Firstly, we examined the adjustments to cope with bile acid concentrations at 0.05% that the pathogens encounter during a potential gallbladder infection. Therefore, we chose the primary bile acids cholic acid (CA) and chenodeoxycholic acid (CDCA) as well as the secondary bile acid deoxycholic acid (DCA), as these are the most prominent bile acids. Secondly, we investigated the adaptations from an aerobic to a microaerophilic environment, as encountered after oral-fecal infection, in the absence and presence of deoxycholic acid (DCA). RESULTS Our findings showed similarities, but also species-specific variations in the response to the different bile acids. Both Enterococcus species showed an IC50 in the range of 0.01- 0.023% for DCA and CDCA in growth experiments and both species were resistant towards 0.05% CA. DCA and CDCA had a strong effect on down-expression of proteins involved in translation, transcription and replication in E. faecalis (424 down-expressed proteins with DCA, 376 down-expressed proteins with CDCA) and in E. faecium (362 down-expressed proteins with DCA, 391 down-expressed proteins with CDCA). Proteins commonly significantly altered in their expression in all bile acid treated samples were identified for both species and represent a "general bile acid response". Among these, various subunits of a V-type ATPase, different ABC-transporters, multi-drug transporters and proteins related to cell wall biogenesis were up-expressed in both species and thus seem to play an essential role in bile acid resistance. Most of the differentially expressed proteins were also identified when E. faecalis was incubated with low levels of DCA at microaerophilic conditions instead of aerobic conditions, indicating that adaptations to bile acids and to a microaerophilic atmosphere can occur simultaneously. CONCLUSIONS Overall, these findings provide a detailed insight into the proteomic stress response of two Enterococcus species and help to understand the resistance potential and the stress-coping mechanisms of these important gastrointestinal bacteria.
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Affiliation(s)
- Annika Dreyer
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany
| | - Christof Lenz
- Bioanalytical Mass Spectrometry Group, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- Department of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
| | - Uwe Groß
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany
| | - Wolfgang Bohne
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany
| | - Andreas Erich Zautner
- Institute for Medical Microbiology and Virology, University Medical Center Göttingen, Göttingen, Germany.
- Institute of Medical Microbiology and Hospital Hygiene, Medical Faculty, Otto-von-Guericke University Magdeburg, Magdeburg, Germany.
- Center for Health and Medical Prevention (CHaMP), Otto-von-Guericke University Magdeburg, Magdeburg, Germany.
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Seidel T. The Plant V-ATPase. FRONTIERS IN PLANT SCIENCE 2022; 13:931777. [PMID: 35845650 PMCID: PMC9280200 DOI: 10.3389/fpls.2022.931777] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 06/03/2022] [Indexed: 05/25/2023]
Abstract
V-ATPase is the dominant proton pump in plant cells. It contributes to cytosolic pH homeostasis and energizes transport processes across endomembranes of the secretory pathway. Its localization in the trans Golgi network/early endosomes is essential for vesicle transport, for instance for the delivery of cell wall components. Furthermore, it is crucial for response to abiotic and biotic stresses. The V-ATPase's rather complex structure and multiple subunit isoforms enable high structural flexibility with respect to requirements for different organs, developmental stages, and organelles. This complexity further demands a sophisticated assembly machinery and transport routes in cells, a process that is still not fully understood. Regulation of V-ATPase is a target of phosphorylation and redox-modifications but also involves interactions with regulatory proteins like 14-3-3 proteins and the lipid environment. Regulation by reversible assembly, as reported for yeast and the mammalian enzyme, has not be proven in plants but seems to be absent in autotrophic cells. Addressing the regulation of V-ATPase is a promising approach to adjust its activity for improved stress resistance or higher crop yield.
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Zeng J, Kang WN, Jin L, Anjum AA, Li GQ. Vacuolar ATPase subunit F is critical for larval survival in Henosepilachna vigintioctopunctata. INSECT MOLECULAR BIOLOGY 2022; 31:177-189. [PMID: 34787941 DOI: 10.1111/imb.12749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 11/02/2021] [Accepted: 11/10/2021] [Indexed: 06/13/2023]
Abstract
Vacuolar ATPase (vATPase) is an important proton pump in insect tissues including gut and Malpighian tubule. Subunit F, one of the 16 subunits of the vATPase holoenzyme, is not well characterized. Here, we found that two HvvATPaseF isoforms were highly expressed in the hindgut and Malpighian tubules (MT) in the 28-spotted lady-beetle Henosepilachna vigintioctopunctata, an agricultural pest that feeds on Solanaceae and Cucurbitaceae. Knockdown of both HvvATPaseF variants by RNA interference (RNAi) delayed larval growth and negatively affected ecdysis and adult emergence. In the midgut, RNAi treatment resulted in the disappearance of peritrophic membrane, the reduction in the size and the impaired integrity of the gut, which was associated with sparse principle cells and an increase in TUNEL- and EdU-positive cells. Whereas the MT were opaque and the tubule lumens were full of urine in dsegfp-fed larvae, the tubules were clear and the tubule lumens were empty in the dsvATPaseF-fed larvae. HvvATPaseF knockdown was also associated with a decrease in the abundance of the fat body and the levels of glucose, trehalose, triglyceride, total soluble amino acids and proteins, and an increase in glycogen. Consistent with the known effects of sugars on chitin formation, both the expression level of a chitin biosynthesis gene and the thickness of the head capsule cuticle were reduced in the HvvATPaseF-depleted beetles. Our results demonstrated that subunit F plays an essential role in H. vigintioctopunctata development.
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Affiliation(s)
- Jie Zeng
- Agriculture Ministry Key Laboratory of Integrated Pest Management on Crops in East China/State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Wei-Nan Kang
- Agriculture Ministry Key Laboratory of Integrated Pest Management on Crops in East China/State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Lin Jin
- Agriculture Ministry Key Laboratory of Integrated Pest Management on Crops in East China/State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Ahmad Ali Anjum
- Agriculture Ministry Key Laboratory of Integrated Pest Management on Crops in East China/State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Guo-Qing Li
- Agriculture Ministry Key Laboratory of Integrated Pest Management on Crops in East China/State and Local Joint Engineering Research Center of Green Pesticide Invention and Application, Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
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Knockdown of Vacuolar ATPase Subunit G Gene Affects Larval Survival and Impaired Pupation and Adult Emergence in Henosepilachna vigintioctopunctata. INSECTS 2021; 12:insects12100935. [PMID: 34680704 PMCID: PMC8538789 DOI: 10.3390/insects12100935] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 09/30/2021] [Accepted: 10/03/2021] [Indexed: 11/17/2022]
Abstract
Simple Summary Vacuolar ATPase (vATPase), a proton pump driven by ATP hydrolysis, acts as a membrane energizer to motivate the movement of ions and nutrients across the cellular membrane in insect guts and Malpighian tubules, among others. The vATPase holoenzyme contains 16 subunits. Out of these subunits, mammalian G subunit includes three isoforms (G1-G3) which are encoded by three distinctive genes. The physiological role of a specific G isoform can be compensated by others. Thus, current experimental evidence on the in vivo function of G is rather limited among eight V1 subunits. In the present paper, particular attention was paid to an insect model, Henosepilachna vigintioctopunctata ladybird, a serious defoliator of Solanaceae and Cucurbitaceae plants in many Asian countries. Given that the beetle is sensitive to RNA interference (RNAi), HvvATPaseG gene was knocked down by ingestion of its corresponding dsRNA at the fourth-instar larval stage. Silence of HvvATPaseG affected larval growth and survival, impaired pupation and adult emergence. Our results provide a basis for further functional research on the vATPase G subunit in insects and suggest new ideas for the management of H. vigintioctopunctata. Abstract The vATPase holoenzyme consists of two functional subcomplexes, the cytoplasmic (peripheral) V1 and the membrane-embedded V0. Both V1 and V0 sectors contain eight subunits, with stoichiometry of A3B3CDE3FG3H in V1 and ac8c’c”def(Voa1p) in V0 respectively. However, the function of G subunit has not been characterized in any non-Drosophilid insect species. In the present paper, we uncovered that HvvATPaseG was actively transcribed from embryo to adult in a Coleopteran pest Henosepilachna vigintioctopunctata. Its mRNA levels peaked in larval hindgut and Malpighian tubules. RNA interference (RNAi)-mediated knockdown of HvvATPaseG significantly reduced larval feeding, affected chitin biosynthesis, destroyed midgut integrity, damaged midgut peritrophic membrane, and retarded larval growth. The function of Malpighian tubules was damaged, the contents of glucose, trehalose, lipid, total soluble amino acids and protein were lowered and the fat bodies were lessened in the HvvATPaseG RNAi larvae, compared with those in the PBS- and dsegfp-fed beetles. In contrast, the amount of glycogen was dramatically increased in the HvvATPaseG depletion ladybirds. As a result, the development was arrested, pupation was inhibited and adult emergence was impaired in the HvvATPaseG hypomorphs. Our results demonstrated that G subunit plays a critical role during larval development in H. vigintioctopunctata.
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Zeng J, Mu LL, Jin L, Ali Anjum A, Li GQ. RNAi of vacuolar-type H +-ATPase genes causes growth delay and molting defect in Henosepilachna vigintioctopunctata. BULLETIN OF ENTOMOLOGICAL RESEARCH 2021; 111:1-10. [PMID: 34112278 DOI: 10.1017/s0007485321000420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Henosepilachna vigintioctopunctata is one of the most serious insect pests to a large number of nightshades and cucurbits. RNA interference (RNAi) triggered by double-stranded RNA (dsRNA) offers a reduced risk approach to control the beetle. Identification of amenable target genes and determination of appropriate life stage for dsRNA treatment are two critical steps in order to improve RNAi efficiency. In the present paper, we identified three vATPase genes, namely HvvATPaseC, HvvATPaseE and HvvATPaseH. We found that the three transcripts were widely expressed in the eggs, first- to fourth-instar larvae, prepupae, pupae and adults. They were abundantly transcribed in the hindgut and Malpighian tubules, in contrast to the epidermis and fat body. Three days' ingestion of dsvATPaseC, dsvATPaseE and dsvATPaseH by the fourth-instar larvae significantly decreased corresponding transcript level by 90.1, 88.9 and 97.2%, greatly reduced larval fresh weight by 28.0, 29.9 and 28.0%, and caused 66.7, 100 and 78.7% larval lethality respectively. Comparably, 3 days' exposure of the third-instar larvae to dsvATPaseC significantly reduced HvvATPaseC mRNA level by 89.5%, decreased approximately 80% of the larval fresh weight, and killed 100% of the treated larvae. Therefore, the three vATPase genes, especially HvvATPaseE, are potential amenable target genes and young larvae are more susceptible to dsRNA. Our findings will enable the development of the dsRNA-based pesticide to control H. vigintioctopunctata.
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Affiliation(s)
- Jie Zeng
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing210095, China
| | - Li-Li Mu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing210095, China
| | - Lin Jin
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing210095, China
| | - Ahmad Ali Anjum
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing210095, China
| | - Guo-Qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing210095, China
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Krah A, Marzinek JK, Bond PJ. Insights into water accessible pathways and the inactivation mechanism of proton translocation by the membrane-embedded domain of V-type ATPases. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:1004-1010. [DOI: 10.1016/j.bbamem.2019.02.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 01/29/2019] [Accepted: 02/27/2019] [Indexed: 01/25/2023]
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9
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Shi Q. Expression profiling of genes coding for abundant proteins in the alkenone body of marine haptophyte alga Tisochrysis lutea. BMC Microbiol 2019; 19:56. [PMID: 30871466 PMCID: PMC6419369 DOI: 10.1186/s12866-019-1430-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 03/01/2019] [Indexed: 11/20/2022] Open
Abstract
Background Several abundant proteins have been identified in lipid body of an alkenone-producing marine haptophyte alga Tisochrysis lutea. The gene expression patterns of these proteins were investigated to better understand their roles in alkenone biosynthesis. For this purpose, T. lutea was first cultured in nitrogen-sufficient medium for biomass production and then shifted to nitrogen-deprived medium to induce lipid body formation. Results There were remarkable increases in the volume of alkenone body (AB) and alkenone content in the alga after they were exposed to nitrogen depletion medium. Relative mRNA levels of the genes coding for the identified proteins V-ATPase subunit VA, V-ATPase subunit Vd, hypothetical protein EMIHUDRAFT_465,517, coccolith scale associated protein-1, cycloartenol-c-24-methyltransferase 1-like and SPFH domain-containing protein were investigated over the culture period. RT-PCR data showed that the expression of all these genes except the gene coding for SPFH domain-containing protein was up-regulated during the transition period from nitrogen-sufficient to nitrogen-deficient medium. Among them, the expression of the coccolith scale associated protein-1 gene was up-regulated 50–650 folds. These up-regulations were consistent with the increased alkenone production in nitrogen-deprived medium, suggesting that these proteins are involved in alkenone biosynthesis in T. lutea. Conclusions Expression analysis of the lipoprotein genes suggests that five out of the six genes are up-regulated and are therefore likely to code for the identified lipoproteins associated with alkenone biosynthesis in T. lutea. These data would help better understand alkenone metabolism and engineer for improved biofuel production in T. lutea.
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Affiliation(s)
- Qing Shi
- School of Scientific Research, China University of Geosciences (Beijing), 29 Xueyuan Road, Beijing, 100083, China. .,State Key Laboratory of Biological and Environmental Geology, China University of Geosciences (Beijing), Beijing, China.
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Duan X, Yang S, Zhang L, Yang T. V-ATPases and osteoclasts: ambiguous future of V-ATPases inhibitors in osteoporosis. Theranostics 2018; 8:5379-5399. [PMID: 30555553 PMCID: PMC6276090 DOI: 10.7150/thno.28391] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 10/10/2018] [Indexed: 12/11/2022] Open
Abstract
Vacuolar ATPases (V-ATPases) play a critical role in regulating extracellular acidification of osteoclasts and bone resorption. The deficiencies of subunit a3 and d2 of V-ATPases result in increased bone density in humans and mice. One of the traditional drug design strategies in treating osteoporosis is the use of subunit a3 inhibitor. Recent findings connect subunits H and G1 with decreased bone density. Given the controversial effects of ATPase subunits on bone density, there is a critical need to review the subunits of V-ATPase in osteoclasts and their functions in regulating osteoclasts and bone remodeling. In this review, we comprehensively address the following areas: information about all V-ATPase subunits and their isoforms; summary of V-ATPase subunits associated with human genetic diseases; V-ATPase subunits and osteopetrosis/osteoporosis; screening of all V-ATPase subunits variants in GEFOS data and in-house data; spectrum of V-ATPase subunits during osteoclastogenesis; direct and indirect roles of subunits of V-ATPases in osteoclasts; V-ATPase-associated signaling pathways in osteoclasts; interactions among V-ATPase subunits in osteoclasts; osteoclast-specific V-ATPase inhibitors; perspective of future inhibitors or activators targeting V-ATPase subunits in the treatment of osteoporosis.
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Affiliation(s)
- Xiaohong Duan
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral Biology, Clinic of Oral Rare and Genetic Diseases, School of Stomatology, the Fourth Military Medical University, 145 West Changle Road, Xi'an 710032, P. R. China
| | - Shaoqing Yang
- State Key Laboratory of Military Stomatology, National Clinical Research Center for Oral Diseases, Department of Oral Biology, Clinic of Oral Rare and Genetic Diseases, School of Stomatology, the Fourth Military Medical University, 145 West Changle Road, Xi'an 710032, P. R. China
| | - Lei Zhang
- Center for Genetic Epidemiology and Genomics, School of Public Health, Medical College of Soochow University, 199 Renai Road, Suzhou, Jiangsu, P. R. China
| | - Tielin Yang
- Key Laboratory of Biomedical Information Engineering of Ministry of Education, and Institute of Molecular Genetics, School of Life Science and Technology, Xi'an Jiaotong University, 28 West Xianning Road, Xi'an 710049, People's Republic of China
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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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Eldakak M, Das A, Zhuang Y, Rohila JS, Glover K, Yen Y. A Quantitative Proteomics View on the Function of Qfhb1, a Major QTL for Fusarium Head Blight Resistance in Wheat. Pathogens 2018; 7:E58. [PMID: 29932155 PMCID: PMC6161305 DOI: 10.3390/pathogens7030058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Revised: 06/18/2018] [Accepted: 06/19/2018] [Indexed: 12/18/2022] Open
Abstract
Fusarium head blight (FHB) is a highly detrimental disease of wheat. A quantitative trait locus for FHB resistance, Qfhb1, is the most utilized source of resistance in wheat-breeding programs, but very little is known about its resistance mechanism. In this study, we elucidated a prospective FHB resistance mechanism by investigating the proteomic signatures of Qfhb1 in a pair of contrasting wheat near-isogenic lines (NIL) after 24 h of inoculation of wheat florets by Fusarium graminearum. Statistical comparisons of the abundances of protein spots on the 2D-DIGE gels of contrasting NILs (fhb1+ NIL = Qfhb1 present; fhb1- NIL = Qfhb1 absent) enabled us to select 80 high-ranking differentially accumulated protein (DAP) spots. An additional evaluation confirmed that the DAP spots were specific to the spikelet from fhb1- NIL (50 spots), and fhb1+ NIL (seven spots). The proteomic data also suggest that the absence of Qfhb1 makes the fhb1- NIL vulnerable to Fusarium attack by constitutively impairing several mechanisms including sucrose homeostasis by enhancing starch synthesis from sucrose. In the absence of Qfhb1, Fusarium inoculations severely damaged photosynthetic machinery; altered the metabolism of carbohydrates, nitrogen and phenylpropanoids; disrupted the balance of proton gradients across relevant membranes; disturbed the homeostasis of many important signaling molecules induced the mobility of cellular repair; and reduced translational activities. These changes in the fhb1- NIL led to strong defense responses centered on the hypersensitive response (HSR), resulting in infected cells suicide and the consequent initiation of FHB development. Therefore, the results of this study suggest that Qfhb1 largely functions to either alleviate HSR or to manipulate the host cells to not respond to Fusarium infection.
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Affiliation(s)
- Moustafa Eldakak
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57006, USA.
- Genetics Department, College of Agriculture, Alexandria University, Alexandria 21526, Egypt.
| | - Aayudh Das
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57006, USA.
- Department of Plant Biology, University of Vermont, Burlington, VT 05405, USA.
| | - Yongbin Zhuang
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57006, USA.
- College of Agronomy, Shandong Agricultural University, Taian 271018, China.
| | - Jai S Rohila
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57006, USA.
- Department of Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD 57006, USA.
- Dale Bumpers National Rice Research Center, Stuttgart, AR 72160, USA.
| | - Karl Glover
- Department of Agronomy, Horticulture, and Plant Science, South Dakota State University, Brookings, SD 57006, USA.
| | - Yang Yen
- Department of Biology and Microbiology, South Dakota State University, Brookings, SD 57006, USA.
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Sharma S, Oot RA, Wilkens S. MgATP hydrolysis destabilizes the interaction between subunit H and yeast V 1-ATPase, highlighting H's role in V-ATPase regulation by reversible disassembly. J Biol Chem 2018; 293:10718-10730. [PMID: 29754144 DOI: 10.1074/jbc.ra118.002951] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 04/22/2018] [Indexed: 01/01/2023] Open
Abstract
Vacuolar H+-ATPases (V-ATPases; V1Vo-ATPases) are rotary-motor proton pumps that acidify intracellular compartments and, in some tissues, the extracellular space. V-ATPase is regulated by reversible disassembly into autoinhibited V1-ATPase and Vo proton channel sectors. An important player in V-ATPase regulation is subunit H, which binds at the interface of V1 and Vo H is required for MgATPase activity in holo-V-ATPase but also for stabilizing the MgADP-inhibited state in membrane-detached V1 However, how H fulfills these two functions is poorly understood. To characterize the H-V1 interaction and its role in reversible disassembly, we determined binding affinities of full-length H and its N-terminal domain (HNT) for an isolated heterodimer of subunits E and G (EG), the N-terminal domain of subunit a (aNT), and V1 lacking subunit H (V1ΔH). Using isothermal titration calorimetry (ITC) and biolayer interferometry (BLI), we show that HNT binds EG with moderate affinity, that full-length H binds aNT weakly, and that both H and HNT bind V1ΔH with high affinity. We also found that only one molecule of HNT binds V1ΔH with high affinity, suggesting conformational asymmetry of the three EG heterodimers in V1ΔH. Moreover, MgATP hydrolysis-driven conformational changes in V1 destabilized the interaction of H or HNT with V1ΔH, suggesting an interplay between MgADP inhibition and subunit H. Our observation that H binding is affected by MgATP hydrolysis in V1 points to H's role in the mechanism of reversible disassembly.
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Affiliation(s)
- Stuti Sharma
- From the Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, New York 13210
| | - Rebecca A Oot
- From the Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, New York 13210
| | - Stephan Wilkens
- From the Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, New York 13210
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14
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Ali MY, Pavasovic A, Dammannagoda LK, Mather PB, Prentis PJ. Comparative molecular analyses of select pH- and osmoregulatory genes in three freshwater crayfish Cherax quadricarinatus, C. destructor and C. cainii. PeerJ 2017; 5:e3623. [PMID: 28852583 PMCID: PMC5572425 DOI: 10.7717/peerj.3623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 07/08/2017] [Indexed: 11/20/2022] Open
Abstract
Systemic acid-base balance and osmotic/ionic regulation in decapod crustaceans are in part maintained by a set of transport-related enzymes such as carbonic anhydrase (CA), Na+/K+-ATPase (NKA), H+-ATPase (HAT), Na+/K+/2Cl− cotransporter (NKCC), Na+/Cl−/HCO\documentclass[12pt]{minimal}
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}{}${}_{3}^{-}$\end{document}3− cotransporter (NBC), Na+/H+ exchanger (NHE), Arginine kinase (AK), Sarcoplasmic Ca+2-ATPase (SERCA) and Calreticulin (CRT). We carried out a comparative molecular analysis of these genes in three commercially important yet eco-physiologically distinct freshwater crayfish, Cherax quadricarinatus, C. destructor and C. cainii, with the aim to identify mutations in these genes and determine if observed patterns of mutations were consistent with the action of natural selection. We also conducted a tissue-specific expression analysis of these genes across seven different organs, including gills, hepatopancreas, heart, kidney, liver, nerve and testes using NGS transcriptome data. The molecular analysis of the candidate genes revealed a high level of sequence conservation across the three Cherax sp. Hyphy analysis revealed that all candidate genes showed patterns of molecular variation consistent with neutral evolution. The tissue-specific expression analysis showed that 46% of candidate genes were expressed in all tissue types examined, while approximately 10% of candidate genes were only expressed in a single tissue type. The largest number of genes was observed in nerve (84%) and gills (78%) and the lowest in testes (66%). The tissue-specific expression analysis also revealed that most of the master genes regulating pH and osmoregulation (CA, NKA, HAT, NKCC, NBC, NHE) were expressed in all tissue types indicating an important physiological role for these genes outside of osmoregulation in other tissue types. The high level of sequence conservation observed in the candidate genes may be explained by the important role of these genes as well as potentially having a number of other basic physiological functions in different tissue types.
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Affiliation(s)
- Muhammad Y Ali
- School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Ana Pavasovic
- School of Biomedical Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Lalith K Dammannagoda
- School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Peter B Mather
- School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
| | - Peter J Prentis
- School of Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, Queensland, Australia
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15
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Sharma S, Wilkens S. Biolayer interferometry of lipid nanodisc-reconstituted yeast vacuolar H + -ATPase. Protein Sci 2017; 26:1070-1079. [PMID: 28241399 DOI: 10.1002/pro.3143] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Revised: 02/15/2017] [Accepted: 02/17/2017] [Indexed: 01/24/2023]
Abstract
Vacuolar H+ -ATPase (V-ATPase) is a large, multisubunit membrane protein complex responsible for the acidification of subcellular compartments and the extracellular space. V-ATPase activity is regulated by reversible disassembly, resulting in cytosolic V1 -ATPase and membrane-integral V0 proton channel sectors. Reversible disassembly is accompanied by transient interaction with cellular factors and assembly chaperones. Quantifying protein-protein interactions involving membrane proteins, however, is challenging. Here we present a novel method to determine kinetic constants of membrane protein-protein interactions using biolayer interferometry (BLI). Yeast vacuoles are solubilized, vacuolar proteins are reconstituted into lipid nanodiscs with native vacuolar lipids and biotinylated membrane scaffold protein (MSP) followed by affinity purification of nanodisc-reconstituted V-ATPase (V1 V0 ND). We show that V1 V0 ND can be immobilized on streptavidin-coated BLI sensors to quantitate binding of a pathogen derived inhibitor and to measure the kinetics of nucleotide dependent enzyme dissociation.
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Affiliation(s)
- Stuti Sharma
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University 750 East Adams Street, Syracuse, New York, 13210
| | - Stephan Wilkens
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University 750 East Adams Street, Syracuse, New York, 13210
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16
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Golder ZJ, Karet Frankl FE. Extra-renal locations of the a4 subunit of H(+)ATPase. BMC Cell Biol 2016; 17:27. [PMID: 27368196 PMCID: PMC4930620 DOI: 10.1186/s12860-016-0106-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Accepted: 06/27/2016] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Vacuolar-type proton pumps help maintain acid-base homeostasis either within intracellular compartments or at specialised plasma membranes. In mammals they are made up of 13 subunits, which form two functional domains. A number of the subunits have variants that display tissue restricted expression patterns such that in specialised cell types they replace the generic subunits at some sub-cellular locations. The tissue restricted a4 subunit has previously been reported at the plasma membrane in the kidney, inner ear, olfactory epithelium and male reproductive tract. RESULTS In this study novel locations of the a4 subunit were investigated using an Atp6v0a4 knockout mouse line in which a LacZ reporter cassette replaced part of the gene. The presence of a4 in the olfactory epithelium was further investigated and the additional presence of C2 and d2 subunits identified. The a4 subunit was found in the uterus of pregnant animals and a4 was identified along with d2 and C2 in the embryonic visceral yolk sac. In the male reproductive tract a4 was seen in the novel locations of the prostatic alveoli and the ampullary glands as well as the previously reported epididymis and vas deferens. CONCLUSIONS The identification of novel locations for the a4 subunit and other tissue-restricted subunits increases the range of unique subunit combinations making up the proton pump. These studies suggest additional roles of the proton pump, indicating a further range of homologue-specific functions for tissue-restricted subunits.
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Affiliation(s)
- Zoe J Golder
- Department of Medical Genetics, University of Cambridge, Cambridge, UK.,Cambridge Institute for Medical Research, Cambridge Biomedical Campus Box 139, Hills Road, Cambridge, CB2 OXY, UK
| | - Fiona E Karet Frankl
- Department of Medical Genetics, University of Cambridge, Cambridge, UK. .,Cambridge Institute for Medical Research, Cambridge Biomedical Campus Box 139, Hills Road, Cambridge, CB2 OXY, UK.
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17
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Mazhab-Jafari MT, Rubinstein JL. Cryo-EM studies of the structure and dynamics of vacuolar-type ATPases. SCIENCE ADVANCES 2016; 2:e1600725. [PMID: 27532044 PMCID: PMC4985227 DOI: 10.1126/sciadv.1600725] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 06/15/2016] [Indexed: 06/06/2023]
Abstract
Electron cryomicroscopy (cryo-EM) has significantly advanced our understanding of molecular structure in biology. Recent innovations in both hardware and software have made cryo-EM a viable alternative for targets that are not amenable to x-ray crystallography or nuclear magnetic resonance (NMR) spectroscopy. Cryo-EM has even become the method of choice in some situations where x-ray crystallography and NMR spectroscopy are possible but where cryo-EM can determine structures at higher resolution or with less time or effort. Rotary adenosine triphosphatases (ATPases) are crucial to the maintenance of cellular homeostasis. These enzymes couple the synthesis or hydrolysis of adenosine triphosphate to the use or production of a transmembrane electrochemical ion gradient, respectively. However, the membrane-embedded nature and conformational heterogeneity of intact rotary ATPases have prevented their high-resolution structural analysis to date. Recent application of cryo-EM methods to the different types of rotary ATPase has led to sudden advances in understanding the structure and function of these enzymes, revealing significant conformational heterogeneity and characteristic transmembrane α helices that are highly tilted with respect to the membrane. In this Review, we will discuss what has been learned recently about rotary ATPase structure and function, with a particular focus on the vacuolar-type ATPases.
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Affiliation(s)
- Mohammad T. Mazhab-Jafari
- Molecular Structure and Function Program, The Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, Ontario M5G 0A4, Canada
| | - John L. Rubinstein
- Molecular Structure and Function Program, The Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, Ontario M5G 0A4, Canada
- Department of Biochemistry, The University of Toronto, 1 King’s College Circle, Toronto, Ontario M5S 1A8, Canada
- Department of Medical Biophysics, The University of Toronto, 101 College Street, Toronto, Ontario M5G 1L7, Canada
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18
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Oot RA, Kane PM, Berry EA, Wilkens S. Crystal structure of yeast V1-ATPase in the autoinhibited state. EMBO J 2016; 35:1694-706. [PMID: 27295975 DOI: 10.15252/embj.201593447] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 05/12/2016] [Indexed: 01/23/2023] Open
Abstract
Vacuolar ATPases (V-ATPases) are essential proton pumps that acidify the lumen of subcellular organelles in all eukaryotic cells and the extracellular space in some tissues. V-ATPase activity is regulated by a unique mechanism referred to as reversible disassembly, wherein the soluble catalytic sector, V1, is released from the membrane and its MgATPase activity silenced. The crystal structure of yeast V1 presented here shows that activity silencing involves a large conformational change of subunit H, with its C-terminal domain rotating ~150° from a position near the membrane in holo V-ATPase to a position at the bottom of V1 near an open catalytic site. Together with biochemical data, the structure supports a mechanistic model wherein subunit H inhibits ATPase activity by stabilizing an open catalytic site that results in tight binding of inhibitory ADP at another site.
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Affiliation(s)
- Rebecca A Oot
- 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
| | - Edward A Berry
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Stephan Wilkens
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, NY, USA
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19
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Chait BT, Cadene M, Olinares PD, Rout MP, Shi Y. Revealing Higher Order Protein Structure Using Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2016; 27:952-65. [PMID: 27080007 PMCID: PMC5125627 DOI: 10.1007/s13361-016-1385-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Revised: 03/14/2016] [Accepted: 03/15/2016] [Indexed: 05/24/2023]
Abstract
The development of rapid, sensitive, and accurate mass spectrometric methods for measuring peptides, proteins, and even intact protein assemblies has made mass spectrometry (MS) an extraordinarily enabling tool for structural biology. Here, we provide a personal perspective of the increasingly useful role that mass spectrometric techniques are exerting during the elucidation of higher order protein structures. Areas covered in this brief perspective include MS as an enabling tool for the high resolution structural biologist, for compositional analysis of endogenous protein complexes, for stoichiometry determination, as well as for integrated approaches for the structural elucidation of protein complexes. We conclude with a vision for the future role of MS-based techniques in the development of a multi-scale molecular microscope. Graphical Abstract ᅟ.
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Affiliation(s)
- Brian T Chait
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, 10065, USA.
| | - Martine Cadene
- CBM, CNRS UPR4301, Rue Charles Sadron, CS 80054, 45071, Orleans Cedex 2, France
| | - Paul Dominic Olinares
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, 10065, USA
| | - Michael P Rout
- Laboratory of Cellular and Structural Biology, The Rockefeller University, New York, NY, 10065, USA
| | - Yi Shi
- Laboratory of Mass Spectrometry and Gaseous Ion Chemistry, The Rockefeller University, New York, NY, 10065, USA
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20
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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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21
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Couoh-Cardel S, Milgrom E, Wilkens S. Affinity Purification and Structural Features of the Yeast Vacuolar ATPase Vo Membrane Sector. J Biol Chem 2015; 290:27959-71. [PMID: 26416888 DOI: 10.1074/jbc.m115.662494] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2015] [Indexed: 12/27/2022] Open
Abstract
The membrane sector (Vo) of the proton pumping vacuolar ATPase (V-ATPase, V1Vo-ATPase) from Saccharomyces cerevisiae was purified to homogeneity, and its structure was characterized by EM of single molecules and two-dimensional crystals. Projection images of negatively stained Vo two-dimensional crystals showed a ring-like structure with a large asymmetric mass at the periphery of the ring. A cryo-EM reconstruction of Vo from single-particle images showed subunits a and d in close contact on the cytoplasmic side of the proton channel. A comparison of three-dimensional reconstructions of free Vo and Vo as part of holo V1Vo revealed that the cytoplasmic N-terminal domain of subunit a (aNT) must undergo a large conformational change upon enzyme disassembly or (re)assembly from Vo, V1, and subunit C. Isothermal titration calorimetry using recombinant subunit d and aNT revealed that the two proteins bind each other with a Kd of ~5 μm. Treatment of the purified Vo sector with 1-palmitoyl-2-hydroxy-sn-glycero-3-[phospho-rac-(1-glycerol)] resulted in selective release of subunit d, allowing purification of a VoΔd complex. Passive proton translocation assays revealed that both Vo and VoΔd are impermeable to protons. We speculate that the structural change in subunit a upon release of V1 from Vo during reversible enzyme dissociation plays a role in blocking passive proton translocation across free Vo and that the interaction between aNT and d seen in free Vo functions to stabilize the Vo sector for efficient reassembly of V1Vo.
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Affiliation(s)
- Sergio Couoh-Cardel
- From the Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210
| | - Elena Milgrom
- From the Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210
| | - Stephan Wilkens
- From the Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210
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22
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Bechara C, Robinson CV. Different Modes of Lipid Binding to Membrane Proteins Probed by Mass Spectrometry. J Am Chem Soc 2015; 137:5240-7. [DOI: 10.1021/jacs.5b00420] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Chérine Bechara
- Department of Chemistry,
Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Carol V. Robinson
- Department of Chemistry,
Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
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23
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Nakanishi A, Kishikawa JI, Tamakoshi M, Yokoyama K. The ingenious structure of central rotor apparatus in VoV1; key for both complex disassembly and energy coupling between V1 and Vo. PLoS One 2015; 10:e0119602. [PMID: 25756791 PMCID: PMC4355294 DOI: 10.1371/journal.pone.0119602] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 01/14/2015] [Indexed: 11/25/2022] Open
Abstract
Vacuolar type rotary H+-ATPases (VoV1) couple ATP synthesis/hydrolysis by V1 with proton translocation by Vo via rotation of a central rotor apparatus composed of the V1-DF rotor shaft, a socket-like Vo-C (eukaryotic Vo-d) and the hydrophobic rotor ring. Reconstitution experiments using subcomplexes revealed a weak binding affinity of V1-DF to Vo-C despite the fact that torque needs to be transmitted between V1-DF and Vo-C for the tight energy coupling between V1 and Vo. Mutation of a short helix at the tip of V1-DF caused intramolecular uncoupling of VoV1, suggesting that proper fitting of the short helix of V1-D into the socket of Vo-C is required for tight energy coupling between V1 and Vo. To account for the apparently contradictory properties of the interaction between V1-DF and Vo-C (weak binding affinity but strict requirement for torque transmission), we propose a model in which the relationship between V1-DF and Vo-C corresponds to that between a slotted screwdriver and a head of slotted screw. This model is consistent with our previous result in which the central rotor apparatus is not the major factor for the association of V1 with Vo (Kishikawa and Yokoyama, J Biol Chem. 2012 24597-24603).
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Affiliation(s)
- Atsuko Nakanishi
- Department of Molecular Biosciences, Kyoto Sangyo University, Motoyama Kamigamo, Kita-ku, Kyoto, Japan
| | - Jun-ichi Kishikawa
- Department of Molecular Biosciences, Kyoto Sangyo University, Motoyama Kamigamo, Kita-ku, Kyoto, Japan
| | - Masatada Tamakoshi
- Department of Molecular Biology, Tokyo University of Pharmacy and Life Science, Horinouchi, Hachioji, Tokyo, Japan
| | - Ken Yokoyama
- Department of Molecular Biosciences, Kyoto Sangyo University, Motoyama Kamigamo, Kita-ku, Kyoto, Japan
- * E-mail:
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24
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Wohlgemuth I, Lenz C, Urlaub H. Studying macromolecular complex stoichiometries by peptide-based mass spectrometry. Proteomics 2015; 15:862-79. [PMID: 25546807 PMCID: PMC5024058 DOI: 10.1002/pmic.201400466] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 11/24/2014] [Accepted: 12/22/2014] [Indexed: 11/11/2022]
Abstract
A majority of cellular functions are carried out by macromolecular complexes. A host of biochemical and spectroscopic methods exists to characterize especially protein/protein complexes, however there has been a lack of a universal method to determine protein stoichiometries. Peptide‐based MS, especially as a complementary method to the MS analysis of intact protein complexes, has now been developed to a point where it can be employed to assay protein stoichiometries in a routine manner. While the experimental demands are still significant, peptide‐based MS has been successfully applied to analyze stoichiometries for a variety of protein complexes from very different biological backgrounds. In this review, we discuss the requirements especially for targeted MS acquisition strategies to be used in this context, with a special focus on the interconnected experimental aspects of sample preparation, protein digestion, and peptide stability. In addition, different strategies for the introduction of quantitative peptide standards and their suitability for different scenarios are compared.
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Affiliation(s)
- Ingo Wohlgemuth
- Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Goettingen, Germany
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25
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Bueler SA, Rubinstein JL. Vma9p need not be associated with the yeast V-ATPase for fully-coupled proton pumping activity in vitro. Biochemistry 2015; 54:853-8. [PMID: 25546637 DOI: 10.1021/bi5013172] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Vacuolar-type ATPases (V-ATPases) acidify numerous intracellular compartments in all eukaryotic cells and are responsible for extracellular acidification in some specialized cells. V-ATPases are large macromolecular complexes with at least 15 different subunits, some of which are found in multiple copies. The main roles of all V-ATPase subunits have been established except for the e subunit, encoded by the gene VMA9 in Saccharomyces cerevisiae, and the Ac45 subunit, which is not found in the S. cerevisiae enzyme. Here we demonstrate that when the S. cerevisiae V-ATPase is solubilized with the detergent dodecylmaltoside (DDM), Vma9p is removed. We further demonstrate that after Vma9p has been removed by detergent the purified enzyme is still able to perform fully-coupled ATP-dependent proton pumping. This observation shows that Vma9p is not necessary in vitro for this principal activity of the V-ATPase.
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Affiliation(s)
- Stephanie A Bueler
- Molecular Structure and Function Program, The Hospital for Sick Children Research Institute , Toronto, Ontario M5G 1X8, Canada
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26
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Zhao J, Rubinstein JL. The study of vacuolar-type ATPases by single particle electron microscopy. Biochem Cell Biol 2014; 92:460-6. [DOI: 10.1139/bcb-2014-0086] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Nature’s molecular machines often work through the concerted action of many different protein subunits, which can give rise to large structures with complex activities. Vacuolar-type ATPases (V-ATPases) are membrane-embedded protein assemblies with a unique rotary catalytic mechanism. The dynamic nature and instability of V-ATPases make structural and functional studies of these enzymes challenging. Electron microscopy (EM) techniques, especially single particle electron cryomicroscopy (cryo-EM) and negative-stain EM, have provided extensive insight into the structure and function of these protein complexes. This minireview outlines what has been learned about V-ATPases using electron microscopy, highlights current challenges for their structural study, and discusses what cryo-EM will allow us to learn about these fascinating enzymes in the future.
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Affiliation(s)
- Jianhua Zhao
- The Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada
- Department of Medical Biophysics, The University of Toronto, 1 Kings College Circle, Toronto, ON M5S 1A8, Canada
| | - John L. Rubinstein
- The Hospital for Sick Children Research Institute, 686 Bay Street, Toronto, ON M5G 0A4, Canada
- Department of Medical Biophysics, The University of Toronto, 1 Kings College Circle, Toronto, ON M5S 1A8, Canada
- Department of Biochemistry, The University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
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27
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De Luca M, Bucci C. A new V-ATPase regulatory mechanism mediated by the Rab interacting lysosomal protein (RILP). Commun Integr Biol 2014; 7:971572. [PMID: 26843904 PMCID: PMC4594554 DOI: 10.4161/cib.29616] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Progressive luminal acidification of intracellular compartments is important for their
functions. Proton transport into the organelle's lumen is mediated by vacuolar
ATPases (V-ATPases) large multi-subunit proton pumps organized into 2 domains, V0 and V1,
working together as a rotary machine. The interaction of each subunit with specific
partners plays a crucial role in controlling V-ATPase activity. Recently, we have shown
that RILP, a Rab7 effector regulating late endocytic traffic and biogenesis of
multivesicular bodies (MVBs), is a specific interactor of the V-ATPase subunit V1G1, a
fundamental component of the peripheral stalk for correct V-ATPase assembly. RILP controls
V1G1 stability and localization affecting V-ATPase assembly and function at the level of
endosomes and lysosomes. The discovery of this new regulatory mechanism for V-ATPase opens
new scenario to the comprehension of organelle's pH regulation and reveals a key role
of RILP in controlling different aspects of endosome to lysosome transport.
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Affiliation(s)
- Maria De Luca
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA); University of Salento ; Lecce, Italy
| | - Cecilia Bucci
- Department of Biological and Environmental Sciences and Technologies (DiSTeBA); University of Salento ; Lecce, Italy
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28
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Fu KY, Guo WC, Lü FG, Liu XP, Li GQ. Response of the vacuolar ATPase subunit E to RNA interference and four chemical pesticides in Leptinotarsa decemlineata (Say). PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2014; 114:16-23. [PMID: 25175645 DOI: 10.1016/j.pestbp.2014.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 07/20/2014] [Accepted: 07/20/2014] [Indexed: 06/03/2023]
Abstract
Vacuolar-type H(+)-ATPases (vATPases) are localized in the apical membranes of nearly all epithelial tissues of insects, energize the membranes to absorb and/or secrete ions and fluids, and play essential roles in many physiological functions. Here we cloned and characterized a 1041-bp full-length vATPase subunit E cDNA (named as LdATPaseE) that encoded a 226-amino acid protein in Leptinotarsa decemlineata. LdATPaseE mRNA levels were constantly increased from egg to the third- and fourth-instar stages, dropped in wandering and pupal stages and were elevated again in the adult stage. It was highly expressed in ileum and rectum, moderately expressed in Malpighian tubules, midgut and foregut, and lowly expressed in fat body, ventral ganglion, epidermis and haemocytes in the fourth instars. After continuously ingested double-stranded RNAs originated from two LdATPaseE fragments LdATPaseE1 and LdATPaseE2, the target mRNA levels in the larvae were reduced by 85% and 55%, the larval growth and survival were significantly affected. Furthermore, topical application of fipronil, butane-fipronil, endosulfan and cypermethrin significantly upregulated LdATPaseE expression up to 8.3, 4.2, 2.8 and 6.2-fold 1 day after experiment, and up to 15.8, 3.4, 3.6 and 4.5-fold 2 days after treatment. It seems that depletion of vATPase subunit E is lethal, indicating that targeting vATPases by dsRNA appears a promising means of combating L. decemlineata. Moreover, vATPase subunit E is a pesticide inducible gene and may play a role in pesticide toxicity.
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Affiliation(s)
- Kai-Yun Fu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Wen-Chao Guo
- Department of Plant Protection, Xinjiang Academy of Agricultural Sciences, Urumqi 830091, China.
| | - Feng-gong Lü
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Xin-ping Liu
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
| | - Guo-qing Li
- Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
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Wilhelm BG, Mandad S, Truckenbrodt S, Kröhnert K, Schäfer C, Rammner B, Koo SJ, Claßen GA, Krauss M, Haucke V, Urlaub H, Rizzoli SO. Composition of isolated synaptic boutons reveals the amounts of vesicle trafficking proteins. Science 2014; 344:1023-8. [PMID: 24876496 DOI: 10.1126/science.1252884] [Citation(s) in RCA: 526] [Impact Index Per Article: 52.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Synaptic vesicle recycling has long served as a model for the general mechanisms of cellular trafficking. We used an integrative approach, combining quantitative immunoblotting and mass spectrometry to determine protein numbers; electron microscopy to measure organelle numbers, sizes, and positions; and super-resolution fluorescence microscopy to localize the proteins. Using these data, we generated a three-dimensional model of an "average" synapse, displaying 300,000 proteins in atomic detail. The copy numbers of proteins involved in the same step of synaptic vesicle recycling correlated closely. In contrast, copy numbers varied over more than three orders of magnitude between steps, from about 150 copies for the endosomal fusion proteins to more than 20,000 for the exocytotic ones.
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Affiliation(s)
- Benjamin G Wilhelm
- Department of Neuro- and Sensory Physiology, University of Göttingen Medical Center, European Neuroscience Institute, Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany. International Max Planck Research School Neurosciences, 37077 Göttingen, Germany
| | - Sunit Mandad
- Bioanalytical Mass Spectrometry Group, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | - Sven Truckenbrodt
- Department of Neuro- and Sensory Physiology, University of Göttingen Medical Center, European Neuroscience Institute, Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany. International Max Planck Research School Molecular Biology, 37077 Göttingen, Germany
| | - Katharina Kröhnert
- Department of Neuro- and Sensory Physiology, University of Göttingen Medical Center, European Neuroscience Institute, Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Christina Schäfer
- Department of Neuro- and Sensory Physiology, University of Göttingen Medical Center, European Neuroscience Institute, Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Burkhard Rammner
- Department of Neuro- and Sensory Physiology, University of Göttingen Medical Center, European Neuroscience Institute, Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany
| | - Seong Joo Koo
- Leibniz Institut für Molekulare Pharmakologie, Department of Molecular Pharmacology and Cell Biology, Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Gala A Claßen
- Leibniz Institut für Molekulare Pharmakologie, Department of Molecular Pharmacology and Cell Biology, Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Michael Krauss
- Leibniz Institut für Molekulare Pharmakologie, Department of Molecular Pharmacology and Cell Biology, Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Volker Haucke
- Leibniz Institut für Molekulare Pharmakologie, Department of Molecular Pharmacology and Cell Biology, Robert-Rössle-Strasse 10, 13125 Berlin, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry Group, Max-Planck-Institute for Biophysical Chemistry, 37077 Göttingen, Germany. Bioanalytics, Department of Clinical Chemistry, University Medical Center Göttingen, 37075 Göttingen, Germany
| | - Silvio O Rizzoli
- Department of Neuro- and Sensory Physiology, University of Göttingen Medical Center, European Neuroscience Institute, Cluster of Excellence Nanoscale Microscopy and Molecular Physiology of the Brain, Göttingen, Germany.
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Muench SP, Rawson S, Eyraud V, Delmas AF, Da Silva P, Phillips C, Trinick J, Harrison MA, Gressent F, Huss M. PA1b inhibitor binding to subunits c and e of the vacuolar ATPase reveals its insecticidal mechanism. J Biol Chem 2014; 289:16399-408. [PMID: 24795045 PMCID: PMC4047407 DOI: 10.1074/jbc.m113.541250] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 04/14/2014] [Indexed: 12/03/2022] Open
Abstract
The vacuolar ATPase (V-ATPase) is a 1MDa transmembrane proton pump that operates via a rotary mechanism fuelled by ATP. Essential for eukaryotic cell homeostasis, it plays central roles in bone remodeling and tumor invasiveness, making it a key therapeutic target. Its importance in arthropod physiology also makes it a promising pesticide target. The major challenge in designing lead compounds against the V-ATPase is its ubiquitous nature, such that any therapeutic must be capable of targeting particular isoforms. Here, we have characterized the binding site on the V-ATPase of pea albumin 1b (PA1b), a small cystine knot protein that shows exquisitely selective inhibition of insect V-ATPases. Electron microscopy shows that PA1b binding occurs across a range of equivalent sites on the c ring of the membrane domain. In the presence of Mg·ATP, PA1b localizes to a single site, distant from subunit a, which is predicted to be the interface for other inhibitors. Photoaffinity labeling studies show radiolabeling of subunits c and e. In addition, weevil resistance to PA1b is correlated with bafilomycin resistance, caused by mutation of subunit c. The data indicate a binding site to which both subunits c and e contribute and inhibition that involves locking the c ring rotor to a static subunit e and not subunit a. This has implications for understanding the V-ATPase mechanism and that of inhibitors with therapeutic or pesticidal potential. It also provides the first evidence for the position of subunit e within the complex.
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Affiliation(s)
- Stephen P Muench
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom,
| | - Shaun Rawson
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom
| | - Vanessa Eyraud
- Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées-Lyon, Université de Lyon, IFR 41, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, Batiment Louis-Pasteur 20, avenue Albert Einstein, F-69621 Villeurbanne, France
| | - Agnès F Delmas
- the Centre de Biophysique Moléculaire, Centre National de la Recherche Scientifique Unité Propre de Recherche 4301, Rue Charles Sadron, 45071 Orléans cedex 2, France
| | - Pedro Da Silva
- Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées-Lyon, Université de Lyon, IFR 41, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, Batiment Louis-Pasteur 20, avenue Albert Einstein, F-69621 Villeurbanne, France
| | - Clair Phillips
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom
| | - John Trinick
- the School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom, and
| | - Michael A Harrison
- From the School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, West Yorkshire, United Kingdom
| | - Frédéric Gressent
- Institut National de la Recherche Agronomique, Institut National des Sciences Appliquées-Lyon, Université de Lyon, IFR 41, UMR203 BF2I, Biologie Fonctionnelle Insectes et Interactions, Batiment Louis-Pasteur 20, avenue Albert Einstein, F-69621 Villeurbanne, France
| | - Markus Huss
- Abteilung Tierphysiologie, Fachbereich Biologie/Chemie Universität Osnabrück, 49069 Osnabrück, Germany
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Marshansky V, Rubinstein JL, Grüber G. Eukaryotic V-ATPase: novel structural findings and functional insights. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:857-79. [PMID: 24508215 DOI: 10.1016/j.bbabio.2014.01.018] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2013] [Revised: 12/25/2013] [Accepted: 01/27/2014] [Indexed: 02/06/2023]
Abstract
The eukaryotic V-type adenosine triphosphatase (V-ATPase) is a multi-subunit membrane protein complex that is evolutionarily related to F-type adenosine triphosphate (ATP) synthases and A-ATP synthases. These ATPases/ATP synthases are functionally conserved and operate as rotary proton-pumping nano-motors, invented by Nature billions of years ago. In the first part of this review we will focus on recent structural findings of eukaryotic V-ATPases and discuss the role of different subunits in the function of the V-ATPase holocomplex. Despite structural and functional similarities between rotary ATPases, the eukaryotic V-ATPases are the most complex enzymes that have acquired some unconventional cellular functions during evolution. In particular, the novel roles of V-ATPases in the regulation of cellular receptors and their trafficking via endocytotic and exocytotic pathways were recently uncovered. In the second part of this review we will discuss these unique roles of V-ATPases in modulation of function of cellular receptors, involved in the development and progression of diseases such as cancer and diabetes as well as neurodegenerative and kidney disorders. Moreover, it was recently revealed that the V-ATPase itself functions as an evolutionarily conserved pH sensor and receptor for cytohesin-2/Arf-family GTP-binding proteins. Thus, in the third part of the review we will evaluate the structural basis for and functional insights into this novel concept, followed by the analysis of the potentially essential role of V-ATPase in the regulation of this signaling pathway in health and disease. Finally, future prospects for structural and functional studies of the eukaryotic V-ATPase will be discussed.
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Affiliation(s)
- Vladimir Marshansky
- Center for Systems Biology, Program in Membrane Biology, Division of Nephrology, Simches Research Center, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Department of Medicine, Harvard Medical School, Boston, MA 02114, USA; Kadmon Pharmaceuticals Corporation, Alexandria Center for Life Science, 450 East 29th Street, New York, NY 10016, USA.
| | - John L Rubinstein
- Molecular Structure and Function Program, The Hospital for Sick Children Research Institute, University of Toronto, Toronto, ON M5G 1X8, Canada; Department of Biochemistry, University of Toronto, Toronto, ON M5G 1X8, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1X8, Canada
| | - Gerhard Grüber
- Nanyang Technological University, Division of Structural Biology and Biochemistry, School of Biological Sciences, Singapore 637551, Republic of Singapore; Bioinformatics Institute, A(⁎)STAR, 60 Nanyang Drive, Singapore 637551, Republic of Singapore
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Muench SP, Scheres SHW, Huss M, Phillips C, Vitavska O, Wieczorek H, Trinick J, Harrison MA. Subunit positioning and stator filament stiffness in regulation and power transmission in the V1 motor of the Manduca sexta V-ATPase. J Mol Biol 2013; 426:286-300. [PMID: 24075871 PMCID: PMC3899036 DOI: 10.1016/j.jmb.2013.09.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 09/04/2013] [Accepted: 09/05/2013] [Indexed: 12/01/2022]
Abstract
The vacuolar H+-ATPase (V-ATPase) is an ATP-driven proton pump essential to the function of eukaryotic cells. Its cytoplasmic V1 domain is an ATPase, normally coupled to membrane-bound proton pump Vo via a rotary mechanism. How these asymmetric motors are coupled remains poorly understood. Low energy status can trigger release of V1 from the membrane and curtail ATP hydrolysis. To investigate the molecular basis for these processes, we have carried out cryo-electron microscopy three-dimensional reconstruction of deactivated V1 from Manduca sexta. In the resulting model, three peripheral stalks that are parts of the mechanical stator of the V-ATPase are clearly resolved as unsupported filaments in the same conformations as in the holoenzyme. They are likely therefore to have inherent stiffness consistent with a role as flexible rods in buffering elastic power transmission between the domains of the V-ATPase. Inactivated V1 adopted a homogeneous resting state with one open active site adjacent to the stator filament normally linked to the H subunit. Although present at 1:1 stoichiometry with V1, both recombinant subunit C reconstituted with V1 and its endogenous subunit H were poorly resolved in three-dimensional reconstructions, suggesting structural heterogeneity in the region at the base of V1 that could indicate positional variability. If the position of H can vary, existing mechanistic models of deactivation in which it binds to and locks the axle of the V-ATPase rotary motor would need to be re-evaluated. Dissociation of vacuolar H+-ATPase domains deactivates its V1 motor. V1 has one “open” catalytic site linked to the stator filament bound by subunit H. Movement of subunit H to prevent rotary catalysis is possible. Three stator filaments project from deactivated V1, indicating inherent stiffness. This work gives new insight into energetic coupling and control in V-ATPases.
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Affiliation(s)
- Stephen P Muench
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Sjors H W Scheres
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
| | - Markus Huss
- Abteilung Tierphysiologie, Fachbereich Biologie/Chemie, Universität Osnabrück, 49069 Osnabrück, Germany
| | - Clair Phillips
- School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Olga Vitavska
- 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.
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Pokhrel R, Service RJ, Debus RJ, Brudvig GW. Mutation of Lysine 317 in the D2 Subunit of Photosystem II Alters Chloride Binding and Proton Transport. Biochemistry 2013; 52:4758-73. [DOI: 10.1021/bi301700u] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Ravi Pokhrel
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107,
United States
| | - Rachel J. Service
- Department
of Biochemistry, University of California, Riverside, California 92521,
United States
| | - Richard J. Debus
- Department
of Biochemistry, University of California, Riverside, California 92521,
United States
| | - Gary W. Brudvig
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107,
United States
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34
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Seidel T, Siek M, Marg B, Dietz KJ. Energization of vacuolar transport in plant cells and its significance under stress. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 304:57-131. [PMID: 23809435 DOI: 10.1016/b978-0-12-407696-9.00002-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The plant vacuole is of prime importance in buffering environmental perturbations and in coping with abiotic stress caused by, for example, drought, salinity, cold, or UV. The large volume, the efficient integration in anterograde and retrograde vesicular trafficking, and the dynamic equipment with tonoplast transporters enable the vacuole to fulfill indispensible functions in cell biology, for example, transient and permanent storage, detoxification, recycling, pH and redox homeostasis, cell expansion, biotic defence, and cell death. This review first focuses on endomembrane dynamics and then summarizes the functions, assembly, and regulation of secretory and vacuolar proton pumps: (i) the vacuolar H(+)-ATPase (V-ATPase) which represents a multimeric complex of approximately 800 kDa, (ii) the vacuolar H(+)-pyrophosphatase, and (iii) the plasma membrane H(+)-ATPase. These primary proton pumps regulate the cytosolic pH and provide the driving force for secondary active transport. Carriers and ion channels modulate the proton motif force and catalyze uptake and vacuolar compartmentation of solutes and deposition of xenobiotics or secondary compounds such as flavonoids. ABC-type transporters directly energized by MgATP complement the transport portfolio that realizes the multiple functions in stress tolerance of plants.
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Affiliation(s)
- Thorsten Seidel
- Biochemistry and Physiology of Plants, Faculty of Biology, Bielefeld University, Bielefeld, Germany.
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35
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Stewart AG, Sobti M, Harvey RP, Stock D. Rotary ATPases: models, machine elements and technical specifications. BIOARCHITECTURE 2013; 3:2-12. [PMID: 23369889 PMCID: PMC3639240 DOI: 10.4161/bioa.23301] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Rotary ATPases are molecular rotary motors involved in biological energy conversion. They either synthesize or hydrolyze the universal biological energy carrier adenosine triphosphate. Recent work has elucidated the general architecture and subunit compositions of all three sub-types of rotary ATPases. Composite models of the intact F-, V- and A-type ATPases have been constructed by fitting high-resolution X-ray structures of individual subunits or sub-complexes into low-resolution electron densities of the intact enzymes derived from electron cryo-microscopy. Electron cryo-tomography has provided new insights into the supra-molecular arrangement of eukaryotic ATP synthases within mitochondria and mass-spectrometry has started to identify specifically bound lipids presumed to be essential for function. Taken together these molecular snapshots show that nano-scale rotary engines have much in common with basic design principles of man made machines from the function of individual “machine elements” to the requirement of the right “fuel” and “oil” for different types of motors.
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Affiliation(s)
- Alastair G Stewart
- The Victor Chang Cardiac Research Institute, Faculty of Medicine, The University of New South Wales, Sydney, NSW, Australia
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Parsons LS, Wilkens S. Probing subunit-subunit interactions in the yeast vacuolar ATPase by peptide arrays. PLoS One 2012; 7:e46960. [PMID: 23071676 PMCID: PMC3470569 DOI: 10.1371/journal.pone.0046960] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 09/07/2012] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Vacuolar (H(+))-ATPase (V-ATPase; V(1)V(o)-ATPase) is a large multisubunit enzyme complex found in the endomembrane system of all eukaryotic cells where its proton pumping action serves to acidify subcellular organelles. In the plasma membrane of certain specialized tissues, V-ATPase functions to pump protons from the cytoplasm into the extracellular space. The activity of the V-ATPase is regulated by a reversible dissociation mechanism that involves breaking and re-forming of protein-protein interactions in the V(1)-ATPase - V(o)-proton channel interface. The mechanism responsible for regulated V-ATPase dissociation is poorly understood, largely due to a lack of detailed knowledge of the molecular interactions that are responsible for the structural and functional link between the soluble ATPase and membrane bound proton channel domains. METHODOLOGY/PRINCIPAL FINDINGS To gain insight into where some of the stator subunits of the V-ATPase associate with each other, we have developed peptide arrays from the primary sequences of V-ATPase subunits. By probing the peptide arrays with individually expressed V-ATPase subunits, we have identified several key interactions involving stator subunits E, G, C, H and the N-terminal domain of the membrane bound a subunit. CONCLUSIONS The subunit-peptide interactions identified from the peptide arrays complement low resolution structural models of the eukaryotic vacuolar ATPase obtained from transmission electron microscopy. The subunit-subunit interaction data are discussed in context of our current model of reversible enzyme dissociation.
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Affiliation(s)
- Lee S. Parsons
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, United States of America
| | - Stephan Wilkens
- Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, United States of America
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37
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Oot RA, Huang LS, Berry EA, Wilkens S. Crystal structure of the yeast vacuolar ATPase heterotrimeric EGC(head) peripheral stalk complex. Structure 2012; 20:1881-92. [PMID: 23000382 DOI: 10.1016/j.str.2012.08.020] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 08/19/2012] [Accepted: 08/20/2012] [Indexed: 12/17/2022]
Abstract
Vacuolar ATPases (V-ATPases) are multisubunit rotary motor proton pumps that function to acidify subcellular organelles in all eukaryotic organisms. V-ATPase is regulated by a unique mechanism that involves reversible dissociation into V₁-ATPase and V₀ proton channel, a process that involves breaking of protein interactions mediated by subunit C, the cytoplasmic domain of subunit "a" and three "peripheral stalks," each made of a heterodimer of E and G subunits. Here, we present crystal structures of a yeast V-ATPase heterotrimeric complex composed of EG heterodimer and the head domain of subunit C (C(head)). The structures show EG heterodimer folded in a noncanonical coiled coil that is stabilized at its N-terminal ends by binding to C(head). The coiled coil is disrupted by a bulge of partially unfolded secondary structure in subunit G and we speculate that this unique feature in the eukaryotic V-ATPase peripheral stalk may play an important role in enzyme structure and regulation by reversible dissociation.
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Affiliation(s)
- Rebecca A Oot
- Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, NY 13210, USA
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Qin A, Cheng TS, Pavlos NJ, Lin Z, Dai KR, Zheng MH. V-ATPases in osteoclasts: structure, function and potential inhibitors of bone resorption. Int J Biochem Cell Biol 2012; 44:1422-35. [PMID: 22652318 DOI: 10.1016/j.biocel.2012.05.014] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2012] [Revised: 05/18/2012] [Accepted: 05/18/2012] [Indexed: 01/06/2023]
Abstract
The vacuolar-type H(+)-ATPase (V-ATPase) proton pump is a macromolecular complex composed of at least 14 subunits organized into two functional domains, V(1) and V(0). The complex is located on the ruffled border plasma membrane of bone-resorbing osteoclasts, mediating extracellular acidification for bone demineralization during bone resorption. Genetic studies from mice to man implicate a critical role for V-ATPase subunits in osteoclast-related diseases including osteopetrosis and osteoporosis. Thus, the V-ATPase complex is a potential molecular target for the development of novel anti-resorptive agents useful for the treatment of osteolytic diseases. Here, we review the current structure and function of V-ATPase subunits, emphasizing their exquisite roles in osteoclastic function. In addition, we compare several distinct classes of V-ATPase inhibitors with specific inhibitory effects on osteoclasts. Understanding the structure-function relationship of the osteoclast V-ATPase may lead to the development of osteoclast-specific V-ATPase inhibitors that may serve as alternative therapies for the treatment of osteolytic diseases.
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Affiliation(s)
- A Qin
- Centre for Orthopaedic Research, School of Surgery, The University of Western Australia, Crawley, Australia.
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Kishikawa JI, Yokoyama K. Reconstitution of vacuolar-type rotary H+-ATPase/synthase from Thermus thermophilus. J Biol Chem 2012; 287:24597-603. [PMID: 22582389 PMCID: PMC3397886 DOI: 10.1074/jbc.m112.367813] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Vacuolar-type rotary H+-ATPase/synthase (VoV1) from Thermus thermophilus, composed of nine subunits, A, B, D, F, C, E, G, I, and L, has been reconstituted from individually isolated V1 (A3B3D1F1) and Vo (C1E2G2I1L12) subcomplexes in vitro. A3B3D and A3B3 also reconstituted with Vo, resulting in a holoenzyme-like complexes. However, A3B3D-Vo and A3B3-Vo did not show ATP synthesis and dicyclohexylcarbodiimide-sensitive ATPase activity. The reconstitution process was monitored in real time by fluorescence resonance energy transfer (FRET) between an acceptor dye attached to subunit F or D in V1 or A3B3D and a donor dye attached to subunit C in Vo. The estimated dissociation constants Kd for VoV1 and A3B3D-Vo were ∼0.3 and ∼1 nm at 25 °C, respectively. These results suggest that the A3B3 domain tightly associated with the two EG peripheral stalks of Vo, even in the absence of the central shaft subunits. In addition, F subunit is essential for coupling of ATP hydrolysis and proton translocation and has a key role in the stability of whole complex. However, the contribution of the F subunit to the association of A3B3 with Vo is much lower than that of the EG peripheral stalks.
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Affiliation(s)
- Jun-ichi Kishikawa
- Department of Molecular Biosciences, Kyoto Sangyo University, Kamigamo-Motoyama, Kita-ku, Kyoto 603-8555, Japan
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Baumann O, Walz B. The blowfly salivary gland - a model system for analyzing the regulation of plasma membrane V-ATPase. JOURNAL OF INSECT PHYSIOLOGY 2012; 58:450-458. [PMID: 22133312 DOI: 10.1016/j.jinsphys.2011.11.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 11/17/2011] [Accepted: 11/18/2011] [Indexed: 05/31/2023]
Abstract
Vacuolar H(+)-ATPases (V-ATPases) are heteromultimeric proteins that use the energy of ATP hydrolysis for the electrogenic transport of protons across membranes. They are common to all eukaryotic cells and are located in the plasma membrane or in membranes of acid organelles. In many insect epithelia, V-ATPase molecules reside in large numbers in the apical plasma membrane and create an electrochemical proton gradient that is used for the acidification or alkalinization of the extracellular space, the secretion or reabsorption of ions and fluids, the import of nutrients, and diverse other cellular activities. Here, we summarize our results on the functions and regulation of V-ATPase in the tubular salivary gland of the blowfly Calliphora vicina. In this gland, V-ATPase activity energizes the secretion of a KCl-rich saliva in response to the neurohormone serotonin (5-HT). Because of particular morphological and physiological features, the blowfly salivary glands are a superior and exemplary system for the analysis of the intracellular signaling pathways and mechanisms that modulate V-ATPase activity and solute transport in an insect epithelium.
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Affiliation(s)
- Otto Baumann
- Institute of Biochemistry and Biology, University of Potsdam, Karl-Liebknecht-Str. 24/25, 14476 Potsdam, Germany.
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Morgner N, Robinson CV. Massign: an assignment strategy for maximizing information from the mass spectra of heterogeneous protein assemblies. Anal Chem 2012; 84:2939-48. [PMID: 22409725 DOI: 10.1021/ac300056a] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electrospray ionization mass spectrometry (ESI-MS) has evolved into a powerful adjunct for structural biology, helping to unravel the quaternary structure of protein complexes. Increasing interest has led to the study of ever larger multicomponent systems. Investigating these large complexes with ESI has meant that progressively more complicated mass spectra have been recorded. Correct assignment of these spectra is essential to maximize the information content available. Here we present a new assignment strategy and a supporting software package that allows the investigation of large heterogeneous systems, previously beyond the scope of full spectral assignment due to their complexity. The strategy involves two parts. The first includes a peak fitting routine to determine charge state distributions and consequently the masses of the various subcomplexes. The second module distinguishes between solution and gas phase products depending on their mass to charge ratio and assigns these charge states to different subunit combinations. These fitting and assignment routines contain many internal checks for consistency and reveal mass shifts, dependent upon desolvation conditions and small molecule binding. Using a rotary ATPase as a working example, we show how this assignment strategy is capable of determining the stoichiometry and interactions of the 8 different subunits within this 29-subunit assembly.
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Affiliation(s)
- Nina Morgner
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford, UK.
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Kane PM. Targeting reversible disassembly as a mechanism of controlling V-ATPase activity. Curr Protein Pept Sci 2012; 13:117-23. [PMID: 22044153 PMCID: PMC3536023 DOI: 10.2174/138920312800493142] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2011] [Revised: 08/05/2011] [Accepted: 08/06/2011] [Indexed: 11/22/2022]
Abstract
Vacuolar proton-translocating ATPases (V-ATPases) are highly conserved proton pumps consisting of a peripheral membrane subcomplex called V1, which contains the sites of ATP hydrolysis, attached to an integral membrane subcomplex called Vo, which encompasses the proton pore. V-ATPase regulation by reversible dissociation, characterized by release of assembled V1 sectors into the cytosol and inhibition of both ATPase and proton transport activities, was first identified in tobacco hornworm and yeast. It has since become clear that modulation of V-ATPase assembly level is also a regulatory mechanism in mammalian cells. In this review, the implications of reversible disassembly for V-ATPase structure are discussed, along with insights into underlying subunit-subunit interactions provided by recent structural work. Although initial experiments focused on glucose deprivation as a trigger for disassembly, it is now clear that V-ATPase assembly can be regulated by other extracellular conditions. Consistent with a complex, integrated response to extracellular signals, a number of different regulatory proteins, including RAVE/rabconnectin, aldolase and other glycolytic enzymes, and protein kinase A have been suggested to control V-ATPase assembly and disassembly. It is likely that multiple signaling pathways dictate the ultimate level of assembly and activity. Tissue-specific V-ATPase inhibition is a potential therapy for osteoporosis and cancer; the possibility of exploiting reversible disassembly in design of novel V-ATPase inhibitors is discussed.
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Affiliation(s)
- Patricia M Kane
- Dept. of Biochemistry and Molecular Biology, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY 13210, USA.
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Oot RA, Wilkens S. Subunit interactions at the V1-Vo interface in yeast vacuolar ATPase. J Biol Chem 2012; 287:13396-406. [PMID: 22367203 DOI: 10.1074/jbc.m112.343962] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Eukaryotic vacuolar ATPase (V-ATPase) is regulated by a reversible dissociation mechanism that involves breaking and reforming of protein-protein interactions at the interface of the V(1)-ATPase and V(o)-proton channel domains. We found previously that the head domain of the single copy C subunit (C(head)) binds one subunit EG heterodimer with high affinity (Oot, R.A. and Wilkens, S. (2010) J. Biol. Chem. 285, 24654-24664). Here we generated a water-soluble construct of the N-terminal domain of the V(o) "a" subunit composed of amino acid residues 104-372 (a(NT(104-372))). Analytical gel filtration chromatography and sedimentation velocity analysis revealed that a(NT(104-372)) undergoes reversible dimerization in a concentration-dependent manner. A low-resolution molecular envelope was calculated for the a(NT(104-372)) dimer using small angle x-ray scattering data. Isothermal titration calorimetry experiments revealed that a(NT(104-372)) binds the C(foot) and EG heterodimer with dissociation constants of 22 and 33 μM, respectively. We speculate that the spatial closeness of the a(NT), C(foot), and EG binding sites in the intact V-ATPase results in a high-avidity interaction that is able to resist the torque of rotational catalysis, and that reversible enzyme dissociation is initiated by breaking either the a(NT(104-372))-C(foot) or a(NT(104-372))-EG interaction by an as-yet unknown signaling mechanism.
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Affiliation(s)
- Rebecca A Oot
- Department of Biochemistry and Molecular Biology, State University of New York Upstate Medical University, Syracuse, New York 13210, USA
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Stewart AG, Lee LK, Donohoe M, Chaston JJ, Stock D. The dynamic stator stalk of rotary ATPases. Nat Commun 2012; 3:687. [PMID: 22353718 PMCID: PMC3293630 DOI: 10.1038/ncomms1693] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2011] [Accepted: 01/19/2012] [Indexed: 11/09/2022] Open
Abstract
Rotary ATPases couple ATP hydrolysis/synthesis with proton translocation across biological membranes and so are central components of the biological energy conversion machinery. Their peripheral stalks are essential components that counteract torque generated by rotation of the central stalk during ATP synthesis or hydrolysis. Here we present a 2.25-Å resolution crystal structure of the peripheral stalk from Thermus thermophilus A-type ATPase/synthase. We identify bending and twisting motions inherent within the structure that accommodate and complement a radial wobbling of the ATPase headgroup as it progresses through its catalytic cycles, while still retaining azimuthal stiffness necessary to counteract rotation of the central stalk. The conformational freedom of the peripheral stalk is dictated by its unusual right-handed coiled-coil architecture, which is in principle conserved across all rotary ATPases. In context of the intact enzyme, the dynamics of the peripheral stalks provides a potential mechanism for cooperativity between distant parts of rotary ATPases. The peripheral stalks of rotary ATPases counteract torque generated by rotation of the central stalk during ATP synthesis or hydrolysis. Stewart et al. report the crystal structure of an A-type ATPase/synthase peripheral stalk and identify bending and twisting motions that permit the radial wobbling of the headgroup.
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Affiliation(s)
- Alastair G Stewart
- Structural and Computational Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, Australia
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45
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Zhou M, Morgner N, Barrera NP, Politis A, Isaacson SC, Matak-Vinković D, Murata T, Bernal RA, Stock D, Robinson CV. Mass spectrometry of intact V-type ATPases reveals bound lipids and the effects of nucleotide binding. Science 2011; 334:380-385. [PMID: 22021858 PMCID: PMC3927129 DOI: 10.1126/science.1210148] [Citation(s) in RCA: 222] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The ability of electrospray to propel large viruses into a mass spectrometer is established and is rationalized by analogy to the atmospheric transmission of the common cold. Much less clear is the fate of membrane-embedded molecular machines in the gas phase. Here we show that rotary adenosine triphosphatases (ATPases)/synthases from Thermus thermophilus and Enterococcus hirae can be maintained intact with membrane and soluble subunit interactions preserved in vacuum. Mass spectra reveal subunit stoichiometries and the identity of tightly bound lipids within the membrane rotors. Moreover, subcomplexes formed in solution and gas phases reveal the regulatory effects of nucleotide binding on both ATP hydrolysis and proton translocation. Consequently, we can link specific lipid and nucleotide binding with distinct regulatory roles.
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Affiliation(s)
- Min Zhou
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ
| | - Nina Morgner
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ
| | - Nelson P Barrera
- Department of Chemistry, Lensfield Road, University of Cambridge CB2 1EW
- Department of Physiology, Pontificia Universidad Católica de Chile, Alameda 340, Santiago, Chile
| | - Argyris Politis
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ
| | - Shoshanna C Isaacson
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ
| | | | - Takeshi Murata
- Department of Chemistry, Graduate School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
| | - Ricardo A Bernal
- Department of Chemistry, University of Texas at El Paso, El Paso, Texas 79968, USA
| | - Daniela Stock
- The Victor Chang Cardiac Research Institute, Lowy Packer Building, 405 Liverpool Street, Darlinghurst NSW 2010
- Faculty of Medicine, University of New South Wales, Sydney 2052, Australia
| | - Carol V Robinson
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ
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Barrera NP, Robinson CV. Advances in the mass spectrometry of membrane proteins: from individual proteins to intact complexes. Annu Rev Biochem 2011; 80:247-71. [PMID: 21548785 DOI: 10.1146/annurev-biochem-062309-093307] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Rapid advances in structural genomics and in large-scale proteomic projects have yielded vast amounts of data on soluble proteins and their complexes. Despite these advances, progress in studying membrane proteins using mass spectrometry (MS) has been slow. This is due in part to the inherent solubility and dynamic properties of these proteins, but also to their low abundance and the absence of polar side chains in amino acid residues. Considerable progress in overcoming these challenges is, however, now being made for all levels of structural characterization. This progress includes MS studies of the primary structure of membrane proteins, wherein sophisticated enrichment and trapping procedures are allowing multiple posttranslational modifications to be defined through to the secondary structure level in which proteins and peptides have been probed using hydrogen exchange, covalent, or radiolytic labeling methods. Exciting possibilities now exist to go beyond primary and secondary structure to reveal the tertiary and quaternary interactions of soluble and membrane subunits within intact assemblies of more than 700 kDa.
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Affiliation(s)
- Nelson P Barrera
- Department of Physiology, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile.
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Molina MF, Qu HQ, Rentfro AR, Nair S, Lu Y, Hanis CL, McCormick JB, Fisher-Hoch SP. Decreased expression of ATP6V1H in type 2 diabetes: a pilot report on the diabetes risk study in Mexican Americans. Biochem Biophys Res Commun 2011; 412:728-31. [PMID: 21871445 DOI: 10.1016/j.bbrc.2011.08.041] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 08/10/2011] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Previous studies in mice and humans observed down-regulation of the gene expression of ATP6V1H associated with type 2 diabetes. This study identified prospectively changes in ATP6V1H expression before and after overt diabetes. METHODS Expression of ATP6V1H in peripheral blood was compared pre and post development of diabetes in nine individuals. RESULTS Considerable variation of ATP6V1H mRNA levels was observed between different individuals. However, within each individual the decrease in expression of ATP6V1H with the development of diabetes was highly statistically significant. CONCLUSIONS ATP6V1H may represent a critical molecular mechanism involved in the development of type 2 diabetes and its compilations through its important regulatory effect on vacuolar-ATPase activity.
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Affiliation(s)
- Melanie F Molina
- Division of Epidemiology, Human Genetics and Environmental Sciences, Brownsville Regional Campus, The University of Texas School of Public Health, Brownsville, TX, USA
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Schnitzer D, Seidel T, Sander T, Golldack D, Dietz KJ. The cellular energization state affects peripheral stalk stability of plant vacuolar H+-ATPase and impairs vacuolar acidification. PLANT & CELL PHYSIOLOGY 2011; 52:946-56. [PMID: 21474463 DOI: 10.1093/pcp/pcr044] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The plant vacuolar H(+)-ATPase takes part in acidifying compartments of the endomembrane system including the secretory pathway and the vacuoles. The structural variability of the V-ATPase complex as well as its presence in different compartments and tissues involves multiple isoforms of V-ATPase subunits. Furthermore, a versatile regulation is essential to allow for organelle- and tissue-specific fine tuning. In this study, results from V-ATPase complex disassembly with a chaotropic reagent, immunodetection and in vivo fluorescence resonance energy transfer (FRET) analyses point to a regulatory mechanism in plants, which depends on energization and involves the stability of the peripheral stalks as well. Lowering of cellular ATP by feeding 2-deoxyglucose resulted in structural alterations within the V-ATPase, as monitored by changes in FRET efficiency between subunits VHA-E and VHA-C. Potassium iodide-mediated disassembly revealed a reduced stability of V-ATPase after 2-deoxyglucose treatment of the cells, but neither the complete V(1)-sector nor VHA-C was released from the membrane in response to 2-deoxyglucose treatment, precluding a reversible dissociation mechanism like in yeast. These data suggest the existence of a regulatory mechanism of plant V-ATPase by modification of the peripheral stator structure that is linked to the cellular energization state. This mechanism is distinct from reversible dissociation as reported for the yeast V-ATPase, but might represent an evolutionary precursor of reversible dissociation.
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Affiliation(s)
- Daniel Schnitzer
- Department of Biochemistry and Physiology of Plants, Faculty of Biology-W5, Bielefeld University, D-33501 Bielefeld, Germany
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Abstract
AbstractThe rotary ATPase family of membrane protein complexes may have only three members, but each one plays a fundamental role in biological energy conversion. The F1Fo-ATPase (F-ATPase) couples ATP synthesis to the electrochemical membrane potential in bacteria, mitochondria and chloroplasts, while the vacuolar H+-ATPase (V-ATPase) operates as an ATP-driven proton pump in eukaryotic membranes. In different species of archaea and bacteria, the A1Ao-ATPase (A-ATPase) can function as either an ATP synthase or an ion pump. All three of these multi-subunit complexes are rotary molecular motors, sharing a fundamentally similar mechanism in which rotational movement drives the energy conversion process. By analogy to macroscopic systems, individual subunits can be assigned to rotor, axle or stator functions. Recently, three-dimensional reconstructions from electron microscopy and single particle image processing have led to a significant step forward in understanding of the overall architecture of all three forms of these complexes and have allowed the organisation of subunits within the rotor and stator parts of the motors to be more clearly mapped out. This review describes the emerging consensus regarding the organisation of the rotor and stator components of V-, A- and F-ATPases, examining core similarities that point to a common evolutionary origin, and highlighting key differences. In particular, it discusses how newly revealed variation in the complexity of the inter-domain connections may impact on the mechanics and regulation of these molecular machines.
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50
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Li X, Zhang M, Zhang H. RNA interference of four genes in adult Bactrocera dorsalis by feeding their dsRNAs. PLoS One 2011; 6:e17788. [PMID: 21445257 PMCID: PMC3060817 DOI: 10.1371/journal.pone.0017788] [Citation(s) in RCA: 110] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2010] [Accepted: 02/11/2011] [Indexed: 02/06/2023] Open
Abstract
Background RNA interference (RNAi) is a powerful method to inhibit gene expression in a sequence specific manner. Recently silencing the target gene through feeding has been successfully carried out in many insect species. Methodology/Principal Findings Escherichia coli strain HT115 was genetically engineered to express dsRNA targeting genes that encode ribosomal protein Rpl19, V type ATPase D subunit, the fatty acid elongase Noa and a small GTPase Rab11. qRT-PCR showed that mRNA level of four target genes was reduced compared to ds-egfp control by feeding either engineered bacteria or dsRNAs. The maximum down-regulation of each gene varied from 35% to 100%. Tissue specific examination indicated that RNAi could be observed not only in midgut but also in other tissues like the ovary, nervous system and fat body. Silencing of rab11 through ingestion of dsRNA killed 20% of adult flies. Egg production was affected through feeding ds-noa and ds-rab11 compared to ds-egfp group. Adult flies were continuously fed with dsRNA and bacteria expressing dsRNA for 14 days and up-regulations of target genes were observed during this process. The transcripts of noa showed up-regulation compared to ds-egfp control group in four tissues on day 7 after continuous feeding either dsRNA or engineered bacteria. The maximum over-expression is 21 times compared to ds-egfp control group. Up-regulation of rab11 mRNA level could be observed in testes on day 7 after continuous bacteria treatment and in midgut on day 2 after ds-rab11 treatment. This phenomenon could also be observed in rpl19 groups. Conclusions Our results suggested that it is feasible to silence genes by feeding dsRNA and bacteria expressing dsRNA in Bactrocera dorsalis. Additionally the over-expression of the target gene after continuously feeding dsRNA or bacteria was observed.
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Affiliation(s)
- Xiaoxue Li
- State Key Laboratory of Agricultural Microbiology, Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control and Institute of Urban and Horticultural Pests, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Mingyan Zhang
- State Key Laboratory of Agricultural Microbiology, Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control and Institute of Urban and Horticultural Pests, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
| | - Hongyu Zhang
- State Key Laboratory of Agricultural Microbiology, Hubei Key Laboratory of Insect Resource Application and Sustainable Pest Control and Institute of Urban and Horticultural Pests, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, People's Republic of China
- * E-mail:
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