6o7t
From Proteopedia
Saccharomyces cerevisiae V-ATPase Vph1-VO
Structural highlights
Function[VATL1_YEAST] Proton-conducting pore forming subunit of the membrane integral V0 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. It is an electrogenic proton pump that generates a proton motive force of 180 mv, inside positive and acidic, in the vacuolar membrane vesicles. [VATO_YEAST] Proton-conducting pore forming subunit of the membrane integral V0 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. [VATL2_YEAST] Proton-conducting pore forming subunit of the membrane integral V0 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells.[1] [2] [VOA1_YEAST] Functions with VMA21 in assembly of the integral membrane sector (also called V0 complex) of the V-ATPase in the endoplasmic reticulum.[3] [VA0E_YEAST] Subunit of the integral membrane V0 complex of vacuolar ATPase. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells.[4] [VPH1_YEAST] Subunit of the integral membrane V0 complex of vacuolar ATPase essential for assembly and catalytic activity. Is present only in vacuolar V-ATPase complexes. Enzymes containing this subunit have a 4-fold higher ratio of proton transport to ATP hydrolysis than complexes containing the Golgi/endosomal isoform and undergo reversible dissociation of V1 and V0 in response to glucose depletion. V-ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells.[5] [6] [7] [VA0D_YEAST] Vacuolar ATPase is responsible for acidifying a variety of intracellular compartments in eukaryotic cells. The active enzyme consists of a catalytic V1 domain attached to an integral membrane V0 proton pore complex. This subunit is a non-integral membrane component of the membrane pore domain and is required for proper assembly of the V0 sector. Might be involved in the regulated assembly of V1 subunits onto the membrane sector or alternatively may prevent the passage of protons through V0 pores. Publication Abstract from PubMedProton-translocating vacuolar-type ATPases (V-ATPases) are necessary for numerous processes in eukaryotic cells, including receptor-mediated endocytosis, protein maturation, and lysosomal acidification. In mammals, V-ATPase subunit isoforms are differentially targeted to various intracellular compartments or tissues, but how these subunit isoforms influence enzyme activity is not clear. In the yeast Saccharomyces cerevisiae, isoform diversity is limited to two different versions of the proton-translocating subunit a: Vph1p, which is targeted to the vacuole, and Stv1p, which is targeted to the Golgi apparatus and endosomes. We show that purified V-ATPase complexes containing Vph1p have higher ATPase activity than complexes containing Stv1p and that the relative difference in activity depends on the presence of lipids. We also show that VO complexes containing Stv1p could be readily purified without attached V1 regions. We used this effect to determine structures of the membrane-embedded VO region with Stv1p at 3.1-A resolution, which we compare with a structure of the VO region with Vph1p that we determine to 3.2-A resolution. These maps reveal differences in the surface charge near the cytoplasmic proton half-channel. Both maps also show the presence of bound lipids, as well as regularly spaced densities that may correspond to ergosterol or bound detergent, around the c-ring. Structural comparison of the vacuolar and Golgi V-ATPases from Saccharomyces cerevisiae.,Vasanthakumar T, Bueler SA, Wu D, Beilsten-Edmands V, Robinson CV, Rubinstein JL Proc Natl Acad Sci U S A. 2019 Mar 25. pii: 1814818116. doi:, 10.1073/pnas.1814818116. PMID:30910982[8] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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