Regulation of Plasma Membrane V-ATPase Activity by Dissociation of Peripheral Subunits

Sumner, John-Paul; Dow, Julian A. T.; Earley, Fergus G.P.; Klein, Uwe; Jäger, Dieter; Wieczorek, Helmut

doi:10.1074/jbc.270.10.5649

Cited by 329 publications

(290 citation statements)

References 36 publications

Supporting

Mentioning

272

Contrasting

Order By: Relevance

“…Considering its placement near the cytoplasmic half-channel, this highly charged loop may modulate the a subunit's affinity for protons entering the V O region from the cytoplasm, a role that is not required in F-type ATP synthase or V/A-ATPase enzymes. V-ATPase activity is modulated by reversible dissociation of the V 1 and V O regions (35,36), and different isoforms of the eukaryotic V-ATPase a subunit target the enzyme to specific cellular locations (37). The loop differs significantly between the two S. cerevisiae isoforms of the a subunit, Vph1p and Stv1p, which have an overall sequence identity of 50%, but only 15% sequence identity within this loop.…”

Section: Resultsmentioning

confidence: 99%

Models for the a subunits of the Thermus thermophilus V/A-ATPase and Saccharomyces cerevisiae V-ATPase enzymes by cryo-EM and evolutionary covariance

Schep

Zhao

Rubinstein

2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Rotary ATPases couple ATP synthesis or hydrolysis to proton translocation across a membrane. However, understanding proton translocation has been hampered by a lack of structural information for the membrane-embedded a subunit. The V/A-ATPase from the eubacterium Thermus thermophilus is similar in structure to the eukaryotic V-ATPase but has a simpler subunit composition and functions in vivo to synthesize ATP rather than pump protons. We determined the T. thermophilus V/A-ATPase structure by cryo-EM at 6.4 Å resolution. Evolutionary covariance analysis allowed tracing of the a subunit sequence within the map, providing a complete model of the rotary ATPase. Comparing the membraneembedded regions of the T. thermophilus V/A-ATPase and eukaryotic V-ATPase from Saccharomyces cerevisiae allowed identification of the α-helices that belong to the a subunit and revealed the existence of previously unknown subunits in the eukaryotic enzyme. Subsequent evolutionary covariance analysis enabled construction of a model of the a subunit in the S. cerevisae V-ATPase that explains numerous biochemical studies of that enzyme. Comparing the two a subunit structures determined here with a structure of the distantly related a subunit from the bovine F-type ATP synthase revealed a conserved pattern of residues, suggesting a common mechanism for proton transport in all rotary ATPases.cryo-EM | evolutionary covariance | V-ATPase | V/A-ATPase | structure V acuolar H + -ATPases (V-ATPases) are large membrane protein complexes responsible for the acidification of intracellular compartments in eukaryotes. These complexes are essential for processes including receptor-mediated endocytosis, coupled transport, and lysosomal degradation (1). V-ATPases localize to the plasma membrane of some specialized cells where they participate in bone resorption by osteoclasts (2) and urine acidification by the α-intercalated cells of the kidney (3). Malfunction or misregulation of these enzymes results in numerous disorders, including osteopetrosis (4) and renal tubular acidosis (5, 6). Expression of V-ATPases on the surfaces of some tumor cells results in increased tumor invasion and metastasis (7). The V/A-ATPase from the thermophilic eubacterium Thermus thermophilus is homologous to the eukaryotic V-ATPase and has a similar overall structure, but is smaller and simpler and functions in vivo as an ATP synthase. V-and V/A-ATPases have similar subunit folds and arrangements of subunits (8-11). The simplified architecture and superior stability of the T. thermophilus V/A-ATPase make it an ideal model to study the structure and function of V-ATPases. Both enzymes are composed of a soluble V 1 catalytic region and a membrane-embedded V O region. The V/A-ATPase subunits I, L, and C in T. thermophilus are homologous to the a, c, and d subunits in eukaryotic V-ATPases, respectively, and, for clarity, the eukaryotic subunit names are used here. With this convention, the T. thermophilus V/A-ATPase contains subunits A 3 B 3 DE 2 FG 2 ac 12 d whereas the eukaryot...

show abstract

Section: Resultsmentioning

confidence: 99%

Models for the a subunits of the Thermus thermophilus V/A-ATPase and Saccharomyces cerevisiae V-ATPase enzymes by cryo-EM and evolutionary covariance

Schep

Zhao

Rubinstein

2016

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…Instead, recent studies suggest that the glycolytic enzyme aldolase may act as a glucose sensor and mediate V-ATPase assembly by binding simultaneously to V 0 and V 1 sector proteins (38). In midgut epithelial cells of M. sexta larvae, another model system for analyzing the structure and function of V-ATPase, reversible V-ATPase dissociation occurs during starvation or moulting (11,12). However, the signaling pathways that induce and regulate V-ATPase assembly͞disassembly are unclear.…”

Section: Discussionmentioning

confidence: 99%

“…Several regulatory mechanisms have been identified (1,2,4,9). One of these is the reversible dissociation of the V 1 sector from the V 0 sector, as revealed by experiments performed in yeast, midgut epithelial cells of the tobacco hornworm Manduca sexta, mammalian dendritic cells, and renal epithelial cells (10)(11)(12)(13)(14)(15)(16). In the dissociated state, V-ATPase is inactive as the V 1 domain does not show ATPase activity under physiological conditions, and the V 0 domain does not translocate protons (14,17,18).…”

mentioning

confidence: 99%

cAMP regulates plasma membrane vacuolar-type H ⁺ -ATPase assembly and activity in blowfly salivary glands

Dames

Zimmermann²,

Schmidt³

et al. 2006

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Reversible assembly of the V0V1 holoenzyme from V0 and V1 subcomplexes is a widely used mechanism for regulation of vacuolar-type H ؉ -ATPases (V-ATPases) in animal cells. In the blowfly (Calliphora vicina) salivary gland, V-ATPase is located in the apical membrane of the secretory cells and energizes the secretion of a KCl-rich saliva in response to the hormone serotonin. We have examined whether the cAMP pathway, known to be activated by serotonin, controls V-ATPase assembly and activity. Fluorescence measurements of pH changes at the luminal surface of isolated glands demonstrate that cAMP, Sp-adenosine-3 ,5 -cyclic monophosphorothioate, or forskolin, similar to serotonin, cause VATPase-dependent luminal acidification. In addition, V-ATPasedependent ATP hydrolysis increases upon treatment with these agents. Immunofluorescence microscopy and pelleting assays have demonstrated further that V1 components become translocated from the cytoplasm to the apical membrane and V-ATPase holoenzymes are assembled at the apical membrane during conditions that increase intracellular cAMP. Because these actions occur without a change in cytosolic Ca 2؉ , our findings suggest that the cAMP pathway mediates the reversible assembly and activation of V-ATPase molecules at the apical membrane upon hormonal stimulus.regulation ͉ translocation ͉ secretion T he vacuolar-type H ϩ -ATPases (V-ATPases) are multisubunit heteromeric complexes that are organized into two domains, designated V 0 and V 1 (1-4). V 0 forms a membranespanning proton-translocating complex; in yeast, it is composed of at least five different subunits termed a, c, cЈ, cЉ, and d, of which subunit c binds bafilomycin A 1 , a specific inhibitor of V-ATPases (5-8). The V 1 sector is attached to the cytoplasmic side of the V 0 sector, consists of at least eight different subunits termed A-H, and contains catalytic and noncatalytic ATPbinding sites. V-ATPase is vital for almost every eukaryotic cell and fulfils a variety of functions. On intracellular acidic membrane systems, such as endosomes, lysosomes, and synaptic vesicles, these proton pumps are involved in protein sorting during biosynthetic and endocytotic pathways, zymogen activation, and transmitter uptake, respectively (3, 4). V-ATPase molecules in the plasma membrane of animal cells, especially on the apical plasma membrane of epithelial cells, contribute to intracellular pH homeostasis, extracellular acidification, or alkalinization, or they energize the plasma membrane for secondary transport processes (3, 4).In some cells, V-ATPase requires a considerable amount of energy. For reasons of economy, it is thus favorable if V-ATPase activity is adapted to the physiological needs of the cell. Several regulatory mechanisms have been identified (1,2,4,9). One of these is the reversible dissociation of the V 1 sector from the V 0 sector, as revealed by experiments performed in yeast, midgut epithelial cells of the tobacco hornworm Manduca sexta, mammalian dendritic cells, and renal epithelial cells (10-16). In th...

show abstract

“…One such situation is the larval midgut of the lepidopteran Manduca sexta. Here the loss of transepithelial voltage across the midgut of Manduca, which drives K + secretion, occurs as a consequence of disassembly of V " from V o , and this disassembly is tightly controlled during stages of the larval development cycle [159]. At such times when V-ATPase is disassembled, the V " sector can account for as much as 2 % of the total cytosolic protein [160].…”

Section: Regulationmentioning

confidence: 99%

The vacuolar H+-ATPase: a universal proton pump of eukaryotes

Finbow

Harrison

1997

Biochemical Journal

240

179

View full text Add to dashboard Cite

The vacuolar H + -ATPase (V-ATPase) is a universal component of eukaryotic organisms. It is present in the membranes of many organelles, where its proton-pumping action creates the low intravacuolar pH found, for example, in lysosomes. In addition, there are a number of differentiated cell types that have V-ATPases on their surface that contribute to the physiological functions of these cells. The V-ATPase is a multi-subunit enzyme composed of a membrane sector and a cytosolic catalytic sector. It is related to the familiar F o F " ATP synthase (F-ATPase), having the same basic architectural construction, and many of the subunits from

show abstract

Regulation of Plasma Membrane V-ATPase Activity by Dissociation of Peripheral Subunits

Cited by 329 publications

References 36 publications

Models for the a subunits of the Thermus thermophilus V/A-ATPase and Saccharomyces cerevisiae V-ATPase enzymes by cryo-EM and evolutionary covariance

Models for the a subunits of the Thermus thermophilus V/A-ATPase and Saccharomyces cerevisiae V-ATPase enzymes by cryo-EM and evolutionary covariance

cAMP regulates plasma membrane vacuolar-type H ⁺ -ATPase assembly and activity in blowfly salivary glands

The vacuolar H+-ATPase: a universal proton pump of eukaryotes

Contact Info

Product

Resources

About

Regulation of Plasma Membrane V-ATPase Activity by Dissociation of Peripheral Subunits

Cited by 329 publications

References 36 publications

Models for the a subunits of the Thermus thermophilus V/A-ATPase and Saccharomyces cerevisiae V-ATPase enzymes by cryo-EM and evolutionary covariance

Models for the a subunits of the Thermus thermophilus V/A-ATPase and Saccharomyces cerevisiae V-ATPase enzymes by cryo-EM and evolutionary covariance

cAMP regulates plasma membrane vacuolar-type H + -ATPase assembly and activity in blowfly salivary glands

The vacuolar H+-ATPase: a universal proton pump of eukaryotes

Contact Info

Product

Resources

About

cAMP regulates plasma membrane vacuolar-type H ⁺ -ATPase assembly and activity in blowfly salivary glands