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Zhao S, Zhang X, Yang L, Wang Y, Jia S, Li X, Wang Z, Yang F, Liang M, Wang X, Wang D. ATP6V0C gene variants were identified in individuals with epilepsy, with or without developmental delay. J Hum Genet 2023; 68:589-597. [PMID: 37161035 DOI: 10.1038/s10038-023-01145-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/06/2023] [Accepted: 03/19/2023] [Indexed: 05/11/2023]
Abstract
The cause of epilepsy with or without developmental disorders was unidentified in a significant proportion of patients. Whole exome sequencing was performed in three unrelated patients with early-onset epilepsy, with or without developmental delay and intellectual disability. We identified de novo heterozygous variants (p.Arg119Trp, p.Val99_Ser102del, c.260_263 + 11delinsGCCCA) in the ATP6V0C gene, which encodes a subunit of vacuolar ATPase. Three-dimensional protein modeling showed that the variant p.Arg119Trp in ATP6V0C affected the hydrogen bonds with the 115th and 123rd residues, and the protein stability. The p.Val99_Ser102del and c.260_263 + 11delinsGCCCA variants in the other two patients resulted in a loss of function with microdeletion or splicing effects. Their seizures and psychomotor developmental outcomes were different, and all patients had a good prognosis. Our study provides evidence that de novo heterozygous ATP6V0C variants are related to epilepsy and associated with or without developmental delay.
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Affiliation(s)
- Siyu Zhao
- Department of Pediatric neurology, Xi'an Children's Hospital, Xi'an, China
| | - Xiaoling Zhang
- Department of neurology, The Mine Hospital of Xu Zhou, Xuzhou, China
| | - Le Yang
- Department of Pediatric neurology, Xi'an Children's Hospital, Xi'an, China
| | - Yan Wang
- Department of Pediatric neurology, Xi'an Children's Hospital, Xi'an, China
| | - ShanShan Jia
- Department of Pediatric neurology, Xi'an Children's Hospital, Xi'an, China
| | - Xia Li
- Department of Pediatric neurology, Xi'an Children's Hospital, Xi'an, China
| | - Zhijing Wang
- Department of Pediatric neurology, Xi'an Children's Hospital, Xi'an, China
| | | | | | - Xiuxia Wang
- Department of Pediatric, The Second Hospital of Heibei Medical University, Shijiazhuang, China.
| | - Dong Wang
- Department of Pediatric neurology, Xi'an Children's Hospital, Xi'an, China.
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2
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Li W, Zhu L, Wu B, Liu Y, Li J, Xu L, Huangfu X, Shi D, Gu L, Chen C. Improving mesophilic anaerobic digestion of food waste by side-stream thermophilic reactor: Activation of methanogenic, key enzymes and metabolism. WATER RESEARCH 2023; 241:120167. [PMID: 37290195 DOI: 10.1016/j.watres.2023.120167] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 05/21/2023] [Accepted: 06/01/2023] [Indexed: 06/10/2023]
Abstract
Anaerobic digestion (AD) is a favorable way to convert organic pollutants, such as food waste (FW), into clean energy through microbial action. This work adopted a side-stream thermophilic anaerobic digestion (STA) strategy to improve a digestive system's efficiency and stability. Results showed that the STA strategy brought higher methane production as well as higher system stability. It quickly adapted to thermal stimulation and increased the specific methane production from 359 mL CH4/g·VS to 439 mL CH4/g·VS, which was also higher than 317 mL CH4/g·VS from single-stage thermophilic anaerobic digestion. Further exploration of the mechanism of STA using metagenomic and metaproteomic analysis revealed enhanced activity of key enzymes. The main metabolic pathway was up-regulated, while the dominant bacteria were concentrated, and the multifunctional Methanosarcina was enriched. These results indicate that STA optimized organic metabolism patterns, comprehensively promoted methane production pathways, and formed various energy conservation mechanisms. Further, the system's limited heating avoided adverse effects from thermal stimulation, and activated enzyme activity and heat shock proteins through circulating slurries, which improved the metabolic process, showing great application potential.
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Affiliation(s)
- Wen Li
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Lirong Zhu
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Baocun Wu
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Yongli Liu
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Jinze Li
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Linji Xu
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Xiaoliu Huangfu
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Dezhi Shi
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
| | - Li Gu
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China.
| | - Cong Chen
- Key laboratory of the Three Gorges Reservoir Region's Eco-environments, Ministry of Education, Institute of Environment and Ecology, Chongqing University, 174 Shapingba Road, Chongqing, 400045, PR China
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Licon-Munoz Y, Michel V, Fordyce CA, Parra KJ. F-actin reorganization by V-ATPase inhibition in prostate cancer. Biol Open 2017; 6:1734-1744. [PMID: 29038303 PMCID: PMC5703614 DOI: 10.1242/bio.028837] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The vacuolar ATPase (V-ATPase) proton pump sustains cellular pH homeostasis, and its inhibition triggers numerous stress responses. However, the cellular mechanisms involved remain largely elusive in cancer cells. We studied V-ATPase in the prostate cancer (PCa) cell line PC-3, which has characteristics of highly metastatic PCa. V-ATPase inhibitors impaired endo-lysosomal pH, vesicle trafficking, migration, and invasion. V-ATPase accrual in the Golgi and recycling endosomes suggests that traffic of internalized membrane vesicles back to the plasma membrane was particularly impaired. Directed movement provoked co-localization of V-ATPase containing vesicles with F-actin near the leading edge of migrating cells. V-ATPase inhibition prompted prominent F-actin cytoskeleton reorganization. Filopodial projections were reduced, which related to reduced migration velocity. F-actin formed novel cytoplasmic rings. F-actin rings increased with extended exposure to sublethal concentrations of V-ATPase inhibitors, from 24 to 48 h, as the amount of alkalinized endo-lysosomal vesicles increased. Studies with chloroquine indicated that F-actin rings formation was pH-dependent. We hypothesize that these novel F-actin rings assemble to overcome widespread traffic defects caused by V-ATPase inhibition, similar to F-actin rings on the surface of exocytic organelles. Summary: V-ATPase activates multiple stress responses. In prostate cancer, sub-lethal concentrations of V-ATPase inhibitors trigger widespread traffic defects. F-actin assembles into rings that mimic those seen during regulated exocytosis.
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Affiliation(s)
- Yamhilette Licon-Munoz
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Vera Michel
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Colleen A Fordyce
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131, USA
| | - Karlett J Parra
- Department of Biochemistry and Molecular Biology, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131, USA
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Higashida H, Yokoyama S, Tsuji C, Muramatsu SI. Neurotransmitter release: vacuolar ATPase V0 sector c-subunits in possible gene or cell therapies for Parkinson's, Alzheimer's, and psychiatric diseases. J Physiol Sci 2017; 67:11-17. [PMID: 27289535 PMCID: PMC10717279 DOI: 10.1007/s12576-016-0462-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 05/27/2016] [Indexed: 12/13/2022]
Abstract
We overview the 16-kDa proteolipid mediatophore, the transmembrane c-subunit of the V0 sector of the vacuolar proton ATPase (ATP6V0C) that was shown to mediate the secretion of acetylcholine. Acetylcholine, serotonin, and dopamine (DA) are released from cell soma and/or dendrites if ATP6V0C is expressed in cultured cells. Adeno-associated viral vector-mediated gene transfer of ATP6V0C into the caudate putamen enhanced the depolarization-induced overflow of endogenous DA in Parkinson-model mice. Motor impairment was ameliorated in hemiparkinsonian model mice when ATP6V0C was expressed with DA-synthesizing enzymes. The review discusses application in the future as a potential tool for gene therapy, cell transplantation therapy, and inducible pluripotent stem cell therapy in neurological diseases, from the view point of recent findings regarding vacuolar ATPase.
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Affiliation(s)
- Haruhiro Higashida
- Kanazawa University Research Center for Child Mental Development, Kanazawa, 920-8640, Japan.
| | - Shigeru Yokoyama
- Kanazawa University Research Center for Child Mental Development, Kanazawa, 920-8640, Japan
| | - Chiharu Tsuji
- Kanazawa University Research Center for Child Mental Development, Kanazawa, 920-8640, Japan
| | - Shin-Ichi Muramatsu
- Division of Neurology, Department of Medicine, Jichi Medical University, Tochigi, 329-0498, Japan
- Center for Gene and Cell Therapy, The Institute of Medical Science, The University of Tokyo, Tokyo, 108-8639, Japan
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Prevention of wear particle-induced osteolysis by a novel V-ATPase inhibitor saliphenylhalamide through inhibition of osteoclast bone resorption. PLoS One 2012; 7:e34132. [PMID: 22509274 PMCID: PMC3324493 DOI: 10.1371/journal.pone.0034132] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 02/22/2012] [Indexed: 11/19/2022] Open
Abstract
Wear particle-induced peri-implant loosening (Aseptic prosthetic loosening) is one of the most common causes of total joint arthroplasty. It is well established that extensive bone destruction (osteolysis) by osteoclasts is responsible for wear particle-induced peri-implant loosening. Thus, inhibition of osteoclastic bone resorption should prevent wear particle induced osteolysis and may serve as a potential therapeutic avenue for prosthetic loosening. Here, we demonstrate for the first time that saliphenylhalamide, a new V-ATPase inhibitor attenuates wear particle-induced osteolysis in a mouse calvarial model. In vitro biochemical and morphological assays revealed that the inhibition of osteolysis is partially attributed to a disruption in osteoclast acidification and polarization, both a prerequisite for osteoclast bone resorption. Interestingly, the V-ATPase inhibitor also impaired osteoclast differentiation via the inhibition of RANKL-induced NF-κB and ERK signaling pathways. In conclusion, we showed that saliphenylhalamide affected multiple physiological processes including osteoclast differentiation, acidification and polarization, leading to inhibition of osteoclast bone resorption in vitro and wear particle-induced osteolysis in vivo. The results of the study provide proof that the new generation V-ATPase inhibitors, such as saliphenylhalamide, are potential anti-resorptive agents for treatment of peri-implant osteolysis.
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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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7
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Hildenbrand ZL, Molugu SK, Stock D, Bernal RA. The C-H peripheral stalk base: a novel component in V1-ATPase assembly. PLoS One 2010; 5:e12588. [PMID: 20838636 PMCID: PMC2933246 DOI: 10.1371/journal.pone.0012588] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 08/10/2010] [Indexed: 11/18/2022] Open
Abstract
Vacuolar ATPases (V-ATPases) are molecular machines responsible for creating electrochemical gradients and preserving pH-dependent cellular compartments by way of proton translocation across the membrane. V-ATPases employ a dynamic rotary mechanism that is driven by ATP hydrolysis and the central rotor stalk. Regulation of this rotational catalysis is the result of a reversible V1Vo-domain dissociation that is required to preserve ATP during instances of cellular starvation. Recently the method by which the free V1-ATPase abrogates the hydrolytic breakdown of ATP upon dissociating from the membrane has become increasingly clear. In this instance the central stalk subunit F adopts an extended conformation to engage in a bridging interaction tethering the rotor and stator components together. However, the architecture by which this mechanism is stabilized has remained ambiguous despite previous work. In an effort to elucidate the method by which the rotational catalysis is maintained, the architecture of the peripheral stalks and their respective binding interactions was investigated using cryo-electron microscopy. In addition to confirming the bridging interaction exuded by subunit F for the first time in a eukaryotic V-ATPase, subunits C and H are seen interacting with one another in a tight interaction that provides a base for the three EG peripheral stalks. The formation of a CE3G3H sub-assembly appears to be unique to the dissociated V-ATPase and highlights the stator architecture in addition to revealing a possible intermediate in the assembly mechanism of the free V1-ATPase.
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Affiliation(s)
- Zacariah L. Hildenbrand
- Department of Chemistry, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Sudheer K. Molugu
- Department of Chemistry, University of Texas at El Paso, El Paso, Texas, United States of America
| | - Daniela Stock
- Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia
- Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
| | - Ricardo A. Bernal
- Department of Chemistry, University of Texas at El Paso, El Paso, Texas, United States of America
- * E-mail:
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Saroussi S, Nelson N. The little we know on the structure and machinery of V-ATPase. J Exp Biol 2009; 212:1604-10. [PMID: 19448070 DOI: 10.1242/jeb.025866] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
SUMMARY
The life of every eukaryotic cell depends on the function of vacuolar H+-ATPase (V-ATPase). Today we know that V-ATPase is vital for many more physiological and biochemical processes than it was expected three decades ago when the enzyme was discovered. These range from a crucial role in the function of internal organelles such as vacuoles, lysosomes, synaptic vesicles, endosomes, secretory granules and the Golgi apparatus to the plasma membrane of several organisms and specific tissues, and specialized cells. The overall structure and mechanism of action of the V-ATPase is supposed to be similar to that of the well-characterized F-type ATP synthase (F-ATPase). Both consist of a soluble catalytic domain (V1 or F1) that is coupled to a membrane-spanning domain (Vo or Fo) by one or more `stalk' components. Owing to the complexity and challenging properties of V-ATPase its study is lagging behind that of its relative F-ATPase. Time will tell whether V-ATPase shares an identical mechanism of action with F-ATPase or its mode of operation is unique.
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Affiliation(s)
- Shai Saroussi
- Biochemistry Department, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Nathan Nelson
- Biochemistry Department, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
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Jefferies KC, Cipriano DJ, Forgac M. Function, structure and regulation of the vacuolar (H+)-ATPases. Arch Biochem Biophys 2008; 476:33-42. [PMID: 18406336 PMCID: PMC2543942 DOI: 10.1016/j.abb.2008.03.025] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2008] [Revised: 03/05/2008] [Accepted: 03/07/2008] [Indexed: 02/07/2023]
Abstract
The vacuolar ATPases (or V-ATPases) are ATP-driven proton pumps that function to both acidify intracellular compartments and to transport protons across the plasma membrane. Intracellular V-ATPases function in such normal cellular processes as receptor-mediated endocytosis, intracellular membrane traffic, prohormone processing, protein degradation and neurotransmitter uptake, as well as in disease processes, including infection by influenza and other viruses and killing of cells by anthrax and diphtheria toxin. Plasma membrane V-ATPases are important in such physiological processes as urinary acidification, bone resorption and sperm maturation as well as in human diseases, including osteopetrosis, renal tubular acidosis and tumor metastasis. V-ATPases are large multi-subunit complexes composed of a peripheral domain (V(1)) responsible for hydrolysis of ATP and an integral domain (V(0)) that carries out proton transport. Proton transport is coupled to ATP hydrolysis by a rotary mechanism. V-ATPase activity is regulated in vivo using a number of mechanisms, including reversible dissociation of the V(1) and V(0) domains, changes in coupling efficiency of proton transport and ATP hydrolysis and changes in pump density through reversible fusion of V-ATPase containing vesicles. V-ATPases are emerging as potential drug targets in treating a number of human diseases including osteoporosis and cancer.
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Affiliation(s)
| | | | - Michael Forgac
- Department of Physiology, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111
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Codlin S, Haines RL, Mole SE. btn1 affects endocytosis, polarization of sterol-rich membrane domains and polarized growth in Schizosaccharomyces pombe. Traffic 2008; 9:936-50. [PMID: 18346214 PMCID: PMC2440566 DOI: 10.1111/j.1600-0854.2008.00735.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
btn1, the Schizosaccharomyces pombe orthologue of the human Batten disease gene CLN3, exerts multiple cellular effects. As well as a role in vacuole pH homoeostasis, we now show that Btn1p is essential for growth at high temperatures. Its absence results in progressive defects at 37°C that culminate in total depolarized growth and cell lysis. These defects are preceded by a progressive failure to correctly polarize sterol-rich domains after cytokinesis and are accompanied by loss of Myo1p localization. Furthermore, we found that in Sz. pombe, sterol spreading is linked to defective formation/polarization of F-actin patches and disruption of endocytosis and that these processes are aberrant in btn1Δ cells. Consistent with a role for Btn1p in polarized growth, Btn1p has an altered location at 37°C and is retained in actin-dependent endomembrane structures near the cell poles or septum.
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Affiliation(s)
- Sandra Codlin
- MRC Laboratory for Molecular Cell Biology, University College London, WC1E 6BT London, UK
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Saroussi S, Nelson N. Vacuolar H+-ATPase—an enzyme for all seasons. Pflugers Arch 2008; 457:581-7. [PMID: 18320212 DOI: 10.1007/s00424-008-0458-9] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Accepted: 01/14/2008] [Indexed: 01/02/2023]
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Voss M, Vitavska O, Walz B, Wieczorek H, Baumann O. Stimulus-induced phosphorylation of vacuolar H(+)-ATPase by protein kinase A. J Biol Chem 2007; 282:33735-33742. [PMID: 17872947 DOI: 10.1074/jbc.m703368200] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Eukaryotic vacuolar-type H(+)-ATPases (V-ATPases) are regulated by the reversible disassembly of the active V(1)V(0) holoenzyme into a cytosolic V(1) complex and a membrane-bound V(0) complex. The signaling cascades that trigger these events in response to changing cellular conditions are largely unknown. We report that the V(1) subunit C of the tobacco hornworm Manduca sexta interacts with protein kinase A and is the only V-ATPase subunit that is phosphorylated by protein kinase A. Subunit C can be phosphorylated as single polypeptide as well as a part of the V(1) complex but not as a part of the V(1)V(0) holoenzyme. Both the phosphorylated and the unphosphorylated form of subunit C are able to reassociate with the V(1) complex from which subunit C had been removed before. Using salivary glands of the blowfly Calliphora vicina in which V-ATPase reassembly and activity is regulated by the neurohormone serotonin via protein kinase A, we show that the membrane-permeable cAMP analog 8-(4-chlorophenylthio)adenosine-3',5'-cyclic monophosphate (8-CPT-cAMP) causes phosphorylation of subunit C in a tissue homogenate and that phosphorylation is reduced by incubation with antibodies against subunit C. Similarly, incubation of intact salivary glands with 8-CPT-cAMP or serotonin leads to the phosphorylation of subunit C, but this is abolished by H-89, an inhibitor of protein kinase A. These data suggest that subunit C binds to and serves as a substrate for protein kinase A and that this phosphorylation may be a regulatory switch for the formation of the active V(1)V(0) holoenzyme.
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Affiliation(s)
- Martin Voss
- Institut für Biochemie und Biologie, Zoophysiologie, Universität Potsdam, Karl-Liebknecht-Strasse 24/25, D-14476 Potsdam, Germany
| | - Olga Vitavska
- Fachbereich Biologie und Chemie, Tierphysiologie, Universität Osnabrück, Barbarastrasse 11, D-49076 Osnabrück, Germany
| | - Bernd Walz
- Institut für Biochemie und Biologie, Zoophysiologie, Universität Potsdam, Karl-Liebknecht-Strasse 24/25, D-14476 Potsdam, Germany
| | - Helmut Wieczorek
- Fachbereich Biologie und Chemie, Tierphysiologie, Universität Osnabrück, Barbarastrasse 11, D-49076 Osnabrück, Germany
| | - Otto Baumann
- Institut für Biochemie und Biologie, Zoophysiologie, Universität Potsdam, Karl-Liebknecht-Strasse 24/25, D-14476 Potsdam, Germany.
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Current awareness on yeast. Yeast 2007. [DOI: 10.1002/yea.1324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Abstract
Bioenergetics and physiology of primary pumps have been revitalized by new insights into the mechanism of energizing biomembranes. Structural information is becoming available, and the three-dimensional structure of F-ATPase is being resolved. The growing understanding of the fundamental mechanism of energy coupling may revolutionize our view of biological processes. The F- and V-ATPases (vacuolar-type ATPase) exhibit a common mechanical design in which nucleotide-binding on the catalytic sector, through a cycle of conformation changes, drives the transmembrane passage of protons by turning a membrane-embedded rotor. This motor can run in forward or reverse directions, hydrolyzing ATP as it pumps protons uphill or creating ATP as protons flow downhill. In contrast to F-ATPases, whose primary function in eukaryotic cells is to form ATP at the expense of the proton-motive force (pmf), V-ATPases function exclusively as an ATP-dependent proton pump. The pmf generated by V-ATPases in organelles and membranes of eukaryotic cells is utilized as a driving force for numerous secondary transport processes. V- and F-ATPases have similar structure and mechanism of action, and several of their subunits evolved from common ancestors. Electron microscopy studies of V-ATPase revealed its general structure at low resolution. Recently, several structures of V-ATPase subunits, solved by X-ray crystallography with atomic resolution, were published. This, together with electron microscopy low-resolution maps of the whole complex, and biochemistry cross-linking experiments, allows construction of a structural model for a part of the complex that may be used as a working hypothesis for future research.
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Affiliation(s)
- Omri Drory
- Department of Biochemistry, The George S. Wise Faculty of Life Sciences, The Daniella Rich Institute for Structural Biology, Tel Aviv University, Tel Aviv, Israel
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