Search Organism: All OrganismsArabidopsis thalianaBacillus subtilis 168Bos taurusCaenorhabditis elegansCanis familiarisCricetulus griseusDanio rerioDrosophila melanogasterEquus caballusEscherichia coli K12 MG1655Gallus gallusHomo sapiensHuman Herpesvirus 1Human Herpesvirus 3Human Herpesvirus 4 Type 1Human Herpesvirus 8 Type MMacaca mulattaMurid Herpesvirus 1Mus musculusNematostella vectensisOryza sativaPan troglodytesRattus norvegicusSaccharomyces cerevisiaeSchizosaccharomyces pombeStrongylocentrotus purpuratusTakifugu rubripesXenopus laevisZea mays home help / support contribute downloads mirrors about us J. Biol. Chem. Jul (2009); 284(29):19522-32 The tether connecting cytosolic (N terminus) and membrane (C terminus) domains of yeast V-ATPase subunit a (Vph1) is required for assembly of V0 subunit d. Ediger B, Melman SD, Pappas DL, Finch M, Applen J, Parra KJ Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine, Albuquerque, New Mexico 87131, USA. Abstract: V-ATPases are molecular motors that reversibly disassemble in vivo. Anchored in the membrane is subunit a. Subunit a has a movable N terminus that switches positions during disassembly and reassembly. Deletions were made at residues securing the N terminus of subunit a (yeast isoform Vph1) to its membrane-bound C-terminal domain in order to understand the role of this conserved region for V-ATPase function. Shrinking of the tether made cells pH-sensitive (vma phenotype) because assembly of V(0) subunit d was harmed. Subunit d did not co-immunoprecipitate with subunit a and the c-ring. Cells contained pools of V(1) and V(0)(-d) that failed to form V(1)V(0), and very low levels of V-ATPase subunits were found at the membrane. Although subunit d expression was stable and at wild-type levels, growth defects were rescued by exogenous VMA6 (subunit d). Stable V(1)V(0) assembled after yeast cells were co-transformed with VMA6 and mutant VPH1. Tether-less V(1)V(0) was delivered to the vacuole and active. It retained 63-71% of the wild-type activity and was responsive to glucose. Tether-less V(1)V(0) disassembled and reassembled after brief glucose depletion and readdition. The N terminus retained binding to V(1) subunits and the C terminus to phosphofructokinase. Thus, no major structural change was generated at the N and C termini of subunit a. We concluded that early steps of V(0) assembly and trafficking were likely impaired by shorter tethers and rescued by VMA6. [PUBMED: 19473972] Copyright © 2009, Tyers Lab, The Samuel Lunenfeld Research Institute, Mount Sinai Hospital, All Rights Reserved. terms and conditions - privacy policy - Osprey Network Visualization System BioGRID: A General Repository for Interaction Datasets. Chris Stark, Bobby-Joe Breitkreutz, Teresa Reguly, Lorrie Boucher, Ashton Breitkreutz, Mike Tyers. Nucleic Acids Res. Jan 1;34:D535-9.