The RAVE complex is essential for stable assembly of the yeast V-ATPase.
Vacuolar proton-translocating ATPases are composed of a peripheral complex, V(1), attached to an integral membrane complex, V(o). Association of the two complexes is essential for ATP-driven proton transport and is regulated post-translationally in response to glucose concentration. A new complex, RAVE, was recently isolated and implicated in glucose-dependent reassembly of V-ATPase complexes that had disassembled in response to glucose deprivation (Seol, J. H., Shevchenko, A., and Deshaies, R. J. (2001) Nat. Cell Biol. 3, 384-391). Here, we provide evidence supporting a role for RAVE in reassembly of the V-ATPase but also demonstrate an essential role in V-ATPase assembly under other conditions. The RAVE complex associates reversibly with V(1) complexes released from the membrane by glucose deprivation but binds constitutively to cytosolic V(1) sectors in a mutant lacking V(o) sectors. V-ATPase complexes from cells lacking RAVE subunits show serious structural and functional defects even in glucose-grown cells or in combination with a mutation that blocks disassembly of the V-ATPase. RAVE small middle dotV(1) interactions are specifically disrupted in cells lacking V(1) subunits E or G, suggesting a direct involvement for these subunits in interaction of the two complexes. Skp1p, a RAVE subunit involved in many different signal transduction pathways, binds stably to other RAVE subunits under conditions that alter RAVE small middle dotV(1) binding; thus, Skp1p recruitment to the RAVE complex does not appear to provide a signal for V-ATPase assembly.
Smardon
Anne M
AM
Department of Biochemistry and Molecular Biology, State University of New York, Upstate Medical University, Syracuse, New York 13210, USA.
Tarsio
Maureen
M
Kane
Patricia M
PM
D018797:Cell Cycle Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D005838:Genotype; D005947:Glucose / Q000378:metabolism; D008954:Models, Biological; D009154:Mutation; D011233:Precipitin Tests; D011485:Protein Binding; D044786:S-Phase Kinase-Associated Proteins; D015398:Signal Transduction; D025262:Vacuolar Proton-Translocating ATPases / Q000737:chemistry* / Q000378:metabolism*
D018797:Cell Cycle Proteins; D005656:Fungal Proteins; D044786:S-Phase Kinase-Associated Proteins; D025262:Vacuolar Proton-Translocating ATPases; D005947:Glucose