151
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Feng Y, Forgac M. Cysteine 254 of the 73-kDa A subunit is responsible for inhibition of the coated vesicle (H+)-ATPase upon modification by sulfhydryl reagents. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)42626-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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152
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153
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Cross RL. Chapter 13 The reaction mechanism of F0F1ATP synthases. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/s0167-7306(08)60181-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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154
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Kane PM, Kuehn MC, Howald-Stevenson I, Stevens TH. Assembly and targeting of peripheral and integral membrane subunits of the yeast vacuolar H(+)-ATPase. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(18)48515-8] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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155
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Raymond CK, Roberts CJ, Moore KE, Howald I, Stevens TH. Biogenesis of the vacuole in Saccharomyces cerevisiae. INTERNATIONAL REVIEW OF CYTOLOGY 1992; 139:59-120. [PMID: 1428679 DOI: 10.1016/s0074-7696(08)61410-2] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- C K Raymond
- Institute of Molecular Biology, University of Oregon, Eugene 97403
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156
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157
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Pan YX, Xu J, Strasser JE, Howell M, Dean GE. Structure and expression of subunit A from the bovine chromaffin cell vacuolar ATPase. FEBS Lett 1991; 293:89-92. [PMID: 1835703 DOI: 10.1016/0014-5793(91)81158-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Subunit A of the vacuolar H(+)-ATPase class is thought to be responsible for the ATP hydrolysis which drives proton-pumping. We report here the cloning and sequence determination of the first mammalian cDNA encoding a bovine vacuolar ATPase subunit A from an adrenal medulla cDNA library. Northern blots of bovine adrenal medulla RNA reveal a message of approximately 3.8 kb. The predicted peptide sequence, consisting of 618 amino acids with a calculated molecular weight of 68397 daltons, is similar to the sequences of the three known subunit A proteins. beta-Galactosidase-subunit A fusion proteins were immuno-decorated by an antiserum raised to the subunit A protein from corn coleoptile vacuoles.
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Affiliation(s)
- Y X Pan
- Department of Physiology and Biophysics, University of Cincinnati College of Medicine, OH 45267-0524
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158
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Nolta K, Padh H, Steck T. Acidosomes from Dictyostelium. Initial biochemical characterization. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)55272-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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159
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Lai S, Watson J, Hansen J, Sze H. Molecular cloning and sequencing of cDNAs encoding the proteolipid subunit of the vacuolar H(+)-ATPase from a higher plant. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)98518-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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160
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Gillespie J, Ozanne S, Tugal B, Percy J, Warren M, Haywood J, Apps D. The vacuolar H(+)-translocating ATPase of renal tubules contains a 115-kDa glycosylated subunit. FEBS Lett 1991; 282:69-72. [PMID: 1827413 DOI: 10.1016/0014-5793(91)80446-a] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Kidney microsomes were fractionated with Triton X-114, to give a fraction enriched in the renal tubule H(+)-translocating ATPase, as judged by the sensitivity of its ATPase activity to bafilomycin A1, and its content of two polypeptides recognized by antibodies directed against subunits of plant tonoplast ATPases. This fraction contained a polypeptide of apparent molecular mass of 115 kDa, that was recognized by an antibody to the largest (120 kDa) subunit of chromaffin-granule membrane H(+)-ATPase, and, like this subunit, was reduced in molecular weight on treatment with glycopeptidase F. We conclude that, like other mammalian vacuolar H(+)-ATPases, the kidney H(+)-ATPase contains a large, glycosylated subunit.
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Affiliation(s)
- J Gillespie
- Department of Biochemistry, University of Edinburgh, UK
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161
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Perin MS, Fried VA, Stone DK, Xie XS, Südhof TC. Structure of the 116-kDa polypeptide of the clathrin-coated vesicle/synaptic vesicle proton pump. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(19)67875-0] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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162
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Matsui W, Kirchhausen T. Stabilization of clathrin coats by the core of the clathrin-associated protein complex AP-2. Biochemistry 1990; 29:10791-8. [PMID: 2125494 DOI: 10.1021/bi00500a011] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
AP-2 is the class of clathrin-associated protein complex found in coated vesicles derived from the plasma membrane of eukaryotic cells. We demonstrate here, using a chemical method, that an AP-2 complex is an asymmetric structure consisting of one large alpha chain, one large beta chain, one medium AP50 chain, and one small AP17 chain. The complex has been shown to contain a core and two appendages. The AP core includes the small AP17 and the medium AP50 chains together with the amino-terminal domains of the large alpha and beta chains. One appendage corresponds to the carboxy-terminal domain of the beta chain. We find that as in the case of the beta chains, the carboxy-terminal portion of the alpha chains is an independently folded domain corresponding to the second appendage. We use limited tryptic proteolysis of clathrin/AP-2 coats to show the release of the appendages from the interior of the coats and the retention of the AP core by the remaining clathrin lattice. In addition, we find that the AP core stabilizes the coat and prevents its depolymerization. These results are consistent with the proposal that the AP core contains the binding site(s) for clathrin, while the alpha- and beta-chain appendages interact with membrane components of coated pits and coated vesicles.
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Affiliation(s)
- W Matsui
- Department of Anatomy and Cellular Biology, Harvard Medical School, Boston, Massachusetts 02115
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163
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Abstract
Many intracellular organelles contain a unique primary, electrogenic proton pump termed the vacuolar H(+)-ATPase. This pump, found in many endocytic, secretory, and storage vesicles in fungal, plant and animal cells, functions, in conjunction with a chloride conductance, to acidify the vesicle interior. Although remotely related to the mitochondrial ATP synthase, the vacuolar H(+)-ATPase is a distinct pump which differs in inhibitor sensitivity, subunit composition and function. The vacuolar H(+)-ATPase transports only protons, and permeable anions (chloride) are required for optimal vesicle acidification. Allosteric and regulatory effects are not yet fully understood. Vesicle acidification appears to be essential for receptor-mediated endocytosis, protein synthesis, and secretion and storage of small solutes such as neurotransmitters. A similar plasma membrane-located H(+)-ATPase may contribute to urinary acidification and cell pH regulation.
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Affiliation(s)
- R W Van Dyke
- Division of Gastroenterology, University of Michigan Medical Center, Ann Arbor
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164
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Floor E, Leventhal PS, Schaeffer SF. Partial purification and characterization of the vacuolar H(+)-ATPase of mammalian synaptic vesicles. J Neurochem 1990; 55:1663-70. [PMID: 2145397 DOI: 10.1111/j.1471-4159.1990.tb04954.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Several major proteins of synaptic vesicles from rat or cow brain sediment as a large complex on sucrose density gradients when solubilized in nonionic detergents. A vacuolar H(+)-ATPase identified by sensitivity to bafilomycin A1 appears to be associated with this oligomeric protein complex. Two subunits of this complex, synaptic vesicle proteins S and U, correspond to the 57-kDa (B) and 39-kDa accessory (Ac39) subunits, respectively, of bovine chromaffin granule vacuolar H(+)-ATPase as shown by Western immunoblot analysis. The five subunits of the oligomeric complex constitute approximately 20% of the total protein of rat brain synaptic vesicles. Taken together, these results strongly suggest that the abundant, multisubunit complex partially purified from brain synaptic vesicles by density gradient centrifugation is a vacuolar H(+)-ATPase. Bafilomycin A1 completely blocks proton pumping in rat brain synaptic vesicles as measured by [14C]methylamine uptake and also blocks catecholamine accumulation measured by [3H]dopamine uptake. Moreover, ATPase activity, [14C]methylamine uptake, and [3H]dopamine uptake are inhibited by bafilomycin A1 at similar I50 values of approximately 1.7 nmol/mg of protein. These findings indicate that the vacuolar H(+)-ATPase is essential for proton pumping as well as catecholamine uptake by mammalian synaptic vesicles.
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Affiliation(s)
- E Floor
- Department of Anatomy, University of Wisconsin Medical School, Madison
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165
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Affiliation(s)
- D K Stone
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas
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166
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Leitch B, Finbow ME. The gap junction-like form of a vacuolar proton channel component appears not to be an artifact of isolation: an immunocytochemical localization study. Exp Cell Res 1990; 190:218-26. [PMID: 1698646 DOI: 10.1016/0014-4827(90)90189-h] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Gap junctional structures containing a 16-kDa intrinsic membrane protein have been isolated from the hepatopancreas of the crustacean Nephrops norvegicus. These structures are double membranes 14-15 nm thick and composed of hexagonal arrays of particles which have a central pore that is penetrated by a cationic negative stain. Membrane preparations have also been isolated from the hepatopancreas and these contain similar gap junctional regions of uniform width. Affinity purified antibodies to the 16-kDa protein bind principally to these gap junctional regions. Antiserum raised against the isolated gap junctional structures binds strongly to the lateral surfaces of the columnar epithelial cells and in particular to gap junction-like regions.
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Affiliation(s)
- B Leitch
- Gatty Marine Station, Department of Biology and Preclinical Medicine, University of St. Andrews, Fife, Scotland
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167
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Cuezva JM, Santarén JF, González P, Valcarce C, Luis AM, Izquierdo JM. Immunological detection of the mitochondrial F1-ATPase alpha subunit in the matrix of rat liver peroxisomes. A protein involved in organelle biogenesis? FEBS Lett 1990; 270:71-5. [PMID: 2146149 DOI: 10.1016/0014-5793(90)81237-i] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Rat liver peroxisomes contain in their matrix the alpha-subunit of the mitochondrial F1-ATPase complex. The identification of this protein in liver peroxisomes has been achieved by immunoelectron microscopy and subcellular fractionation. No beta-subunit of the mitochondrial F1-ATPase complex was detected in the peroxisomal fractions obtained in sucrose gradients or in Nycodenz pelletted peroxisomes. The consensus peroxisomal targeting sequence (Ala-Lys-Leu) is found at the carboxy terminus of the mature alpha-subunit from bovine heart and rat liver mitochondria. Due to the dual subcellular localization of the alpha-subunit and to the structural homologies that exist between this protein and molecular chaperones [(1990) Biol. Chem. 265, 7713-7716] it is suggested that the protein should perform another functional role(s) in both organelles, plus to its characteristic involvement in the regulation of mitochondrial ATPase activity.
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Affiliation(s)
- J M Cuezva
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, Spain
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168
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169
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Abstract
The fungal vacuole is an extremely complex organelle that is involved in a wide variety of functions. The vacuole not only carries out degradative processes, the role most often ascribed to it, but also is the primary storage site for certain small molecules and biosynthetic precursors such as basic amino acids and polyphosphate, plays a role in osmoregulation, and is involved in the precise homeostatic regulation of cytosolic ion and basic amino acid concentration and intracellular pH. These many functions necessitate an intricate interaction between the vacuole and the rest of the cell; the vacuole is part of both the secretory and endocytic pathways and is also directly accessible from the cytosol. Because of the various roles and properties of the vacuole, it has been possible to isolate mutants which are defective in various vacuolar functions including the storage and uptake of metabolites, regulation of pH, sorting and processing of vacuolar proteins, and vacuole biogenesis. These mutants show a remarkable degree of genetic overlap, suggesting that these functions are not individual, discrete properties of the vacuole but, rather, are closely interrelated.
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Affiliation(s)
- D J Klionsky
- Division of Biology, California Institute of Technology, Pasadena 91125
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170
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Hanada H, Moriyama Y, Maeda M, Futai M. Kinetic studies of chromaffin granule H+-ATPase and effects of bafilomycin A1. Biochem Biophys Res Commun 1990; 170:873-8. [PMID: 2143378 DOI: 10.1016/0006-291x(90)92172-v] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Vacuolar type H+-ATPase purified from bovine chromaffin granules did not show simple Michaelis-Menten type kinetics, and had apparent Km values of 5 microM, 30 microM and 300 microM. These three Km values suggested the presence of catalytic cooperativity during steady-state hydrolysis. The single turnover rate was 10(-3)-fold the maximal velocity of the enzyme and similar to the rate estimated from the velocity of steady-state hydrolysis with the smallest Km value (5 microM). The H(+)-ATPase was inhibited by the stoichiometric binding of bafilomycin A1, a specific inhibitor of vacuolar type H(+)-ATPase. This inhibitor not only lowered the rate of ATP hydrolysis at the single catalytic site, but also affected the catalytic cooperativity of the enzyme.
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Affiliation(s)
- H Hanada
- Department of Organic Chemistry and Biochemistry, Osaka University, Japan
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171
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Structure and function of the promoter of the carrot V-type H(+)-ATPase catalytic subunit gene. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39020-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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172
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Hirata R, Ohsumk Y, Nakano A, Kawasaki H, Suzuki K, Anraku Y. Molecular structure of a gene, VMA1, encoding the catalytic subunit of H(+)-translocating adenosine triphosphatase from vacuolar membranes of Saccharomyces cerevisiae. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39210-5] [Citation(s) in RCA: 348] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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173
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Matsuura-Endo C, Maeshima M, Yoshida S. Subunit composition of vacuolar membrane H(+)-ATPase from mung bean. EUROPEAN JOURNAL OF BIOCHEMISTRY 1990; 187:745-51. [PMID: 2137412 DOI: 10.1111/j.1432-1033.1990.tb15362.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The vacuolar H(+)-ATPase from mung bean hypocotyls was solubilized from the membrane with lysophosphatidycholine and purified by QAE-Toyopearl column chromatography. The purified ATPase was active only in the presence of exogenous phospholipid and was inhibited by nitrate, dicyclohexyl carbodiimide and Triton X-100, but not by vanadate or azide. Dodecyl sulfate/polyacrylamide gel electrophoresis of the purified ATPase yielded ten polypeptides of molecular masses of 68 kDa, 57 kDa, 44 kDa, 43 kDa, 38 kDa, 37 kDa 32 kDa, 16 kDa, 13 kDa and 12 kDa. All polypeptides remained in the peak activity fraction after glycerol density gradient centrifugation. Nine of them, excluding the 43-kDa polypeptide, comigrated in a polyacrylamide gradient gel in the presence of 0.1% Triton X-100. The 16-kDa polypeptide could be labeled with [14C]dicyclohexylcarbodiimide. The amino-terminal amino acid sequence of the isolated 68-kDa polypeptide generally agreed with that deduced from the cDNA for the carrot 69-kDa subunit [Zimniak, L., Dittrich, P., Gogarten, J. P., Kibak, H. & Taiz, L. (1988) J. Biol. Chem. 263, 9102-9112]. Thus, mung bean vacuolar H(+)-ATPase seems to consist of nine distinct subunits.
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Affiliation(s)
- C Matsuura-Endo
- Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan
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174
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Cross RL, Taiz L. Gene duplication as a means for altering H+/ATP ratios during the evolution of FoF1 ATPases and synthases. FEBS Lett 1990; 259:227-9. [PMID: 2136729 DOI: 10.1016/0014-5793(90)80014-a] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In the evolution of the FoF1 family of proton-translocating membrane complexes, two reversals in function appear to have occurred, first changing it from an ATPase to an ATP synthase and then back again to an ATPase. Here we suggest that with each change in function, the ratio of protons transported per ATP hydrolyzed or synthesized (H+/ATP) was altered in order for the complex to better adapt to its new role. We propose that this was accomplished by gene duplication with partial loss in the number of functional catalytic sites (to increase H+/ATP) or functional proton channels (to decrease H+/ATP). This method of changing the H+/ATP ratio preserved overall structural features of the complex essential to energy coupling.
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Affiliation(s)
- R L Cross
- Department of Biochemistry and Molecular Biology, SUNY Health Science Center, Syracuse 13210
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175
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REA PHILIPA, TURNER JANICEC. Tonoplast Adenosine Triphosphatase and Inorganic Pyrophosphatase. METHODS IN PLANT BIOCHEMISTRY 1990. [DOI: 10.1016/b978-0-12-461013-2.50035-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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176
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Adachi I, Arai H, Pimental R, Forgac M. Proteolysis and orientation on reconstitution of the coated vesicle proton pump. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)40143-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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177
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178
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179
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Parry RV, Turner JC, Rea PA. High Purity Preparations of Higher Plant Vacuolar H+-ATPase Reveal Additional Subunits. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)47213-x] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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180
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Abstract
Proton-ATPases can be divided into three classes denoted as P-, F-, and V-ATPases. The P-ATPases are evolutionarily distinct from the F- and V-type ATPases which have been shown to be related, probably evolved from a common ancestral enzyme. Like F-ATPases, V-ATPases are composed of two distinct structures: a catalytic sector that is hydrophilic in nature and a hydrophobic membrane sector which functions in proton conduction. Recent studies on the molecular biology of vacuolar H+-ATPases revealed surprising findings about the evolution of pronon pumps as well as important clues for the evolution of eukaryotic cells.
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Affiliation(s)
- N Nelson
- Roche Institute of Molecular Biology, Roche Research Center, Nutley, New Jersey 07110
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181
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Abstract
Recently a new class of proton-translocating ATPases has been localized to endomembrane compartments in plant, fungal, and mammalian cells. These proton pumps are large hetero-oligomers which have an ATP hydrolytic sector that is functionally and structurally distinct from a transmembranous proton pore. Enzymatic characteristics of these proton pumps are discussed as well as the current state of knowledge regarding subunit composition and function. In addition, recent primary sequence data are discussed which indicate that these proton pumps share a common ancestor with F1F0-type proton pumps of mitochondria.
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Affiliation(s)
- D K Stone
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas 75235
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182
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Bowman BJ, Dschida WJ, Harris T, Bowman EJ. The vacuolar ATPase of Neurospora crassa contains an F1-like structure. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(19)84874-3] [Citation(s) in RCA: 119] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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183
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Affiliation(s)
- R Blostein
- Department of Medicine, McGill University, Montreal, Quebec, Canada
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184
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Affiliation(s)
- A L Hubbard
- Department of Cell Biology and Anatomy, Johns Hopkins University School of Medicine, Baltimore, Maryland
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185
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186
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Moriyama Y, Nelson N. Lysosomal H+-translocating ATPase has a similar subunit structure to chromaffin granule H+-ATPase complex. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 980:241-7. [PMID: 2522796 DOI: 10.1016/0005-2736(89)90405-7] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Subunit structure of the lysosomal H+-ATPase was investigated using cold inactivation, immunological cross-reactivity with antibodies against individual subunits of the H+-ATPase from chromaffin granules and chemical modification with N,N'-dicyclohexyl[14C]carbodiimide. The lysosomal H+-ATPase was irreversibly inhibited when incubated at 0 degrees C in the presence of chloride or nitrate and MgATP. Inactivation in the cold resulted in the release of several polypeptides (72, 57, 41, 34 and 33 kDa) from the membrane, which had the same electrophoretic mobility as the corresponding subunits of chromaffin granule H+-ATPase. Cross-reactivity of antibodies revealed that the 72, 57 and 34 kDa polypeptides were immunologically identical to the corresponding subunits of chromaffin granule H+-ATPase. Dicyclohexylcarbodiimide, which inhibits proton translocation in the vacuolar ATPase, predominantly labeled two polypeptides of 18 and 15 kDa, which compose the membrane sector of the enzyme. These results suggest that the lysosomal H+-ATPase is a multimeric enzyme, whose subunit structure is similar to the chromaffin granule H+-ATPase. The subunit structure of other vacuolar H+-ATPases, revealed by cold inactivation and immunological cross-reactivity, is also presented.
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Affiliation(s)
- Y Moriyama
- Roche Institute of Molecular Biology, Roche Research Center, Nutley, NJ 07110
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187
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Nelson H, Nelson N. The progenitor of ATP synthases was closely related to the current vacuolar H+-ATPase. FEBS Lett 1989; 247:147-53. [PMID: 2540044 DOI: 10.1016/0014-5793(89)81259-1] [Citation(s) in RCA: 136] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The gene encoding the proteolipid of the vacuolar H+-ATPase of yeast was cloned and sequenced. The deduced amino acid sequence of the yeast protein is highly homologous to that of the proteolipid from bovine chromaffin granules. In contrast to other membrane proteins the transmembrane segments of the bovine and yeast proteolipids were much more conserved than the hydrophilic parts. The fourth transmembrane segment, which contains the DCCD-binding site, was conserved 100%. Comparison of vacuolar and eubacterial proteolipids revealed a homology which pointed to a common ancestral gene that underwent gene duplication to form the vacuolar proteolipids. Additional support for this notion came from the amino acid sequences of subunits involved in the catalytic sectors of archaebacterial ATP synthase and plant and yeast vacuolar H+-ATPases, which reveal extensive sequence homology. Slight, but significant, homology between the archaebacterial and eubacterial ATP synthases was observed. These observations might suggest that the progenitor of ATP synthases was closely related to the present vacuolar H+-ATPases.
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Affiliation(s)
- H Nelson
- Roche Institute of Molecular Biology, Roche Research Center, Nutley, NJ 07110
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188
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189
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190
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191
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Abstract
Clathrin polymerization at the cytoplasmic side of the plasma membrane forms coated pits and vesicles that mediate uptake of cell surface receptors. Clathrin-coated vesicles have also been implicated in protein export but definition of their precise role has been controversial. Recent advances in characterization of the clathrin subunits and additional coated vesicle components have identified molecular interactions involved in clathrin polymerization and coated vesicle formation, and have provided new approaches to investigating its function. These studies suggest that clathrin's role, in both inward and outward membrane traffic, is to facilitate receptor transport by a concentration and sorting process that initiates targeting to specific intracellular compartments.
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Affiliation(s)
- F M Brodsky
- Department of Pharmacy, School of Pharmacy, University of California, San Francisco 94143
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