Subunit organization and Rab interactions of Vps-C protein complexes that control endolysosomal membrane traffic
Open Access
- 15 April 2011
- journal article
- Published by American Society for Cell Biology (ASCB) in Molecular Biology of the Cell
- Vol. 22 (8), 1353-1363
- https://doi.org/10.1091/mbc.e10-03-0260
Abstract
Traffic through late endolysosomal compartments is regulated by sequential signaling of small G proteins of the Rab5 and Rab7 families. The Saccharomyces cerevisiae Vps-C protein complexes CORVET (class C core vacuole/endosome tethering complex) and HOPS (homotypic fusion and protein transport) interact with endolysosomal Rabs to coordinate their signaling activities. To better understand these large and intricate complexes, we performed interaction surveys to assemble domain-level interaction topologies for the eight Vps-C subunits. We identified numerous intersubunit interactions and up to six Rab-binding sites. Functional modules coordinate the major Rab interactions within CORVET and HOPS. The CORVET-specific subunits, Vps3 and Vps8, form a subcomplex and physically and genetically interact with the Rab5 orthologue Vps21. The HOPS-specific subunits, Vps39 and Vps41, also form a subcomplex. Both subunits bind the Rab7 orthologue Ypt7, but with distinct nucleotide specificities. The in vivo functions of four RING-like domains within Vps-C subunits were analyzed and shown to have distinct functions in endolysosomal transport. Finally, we show that the CORVET- and HOPS-specific subunits Vps3 and Vps39 bind the Vps-C core through a common region within the Vps11 C-terminal domain (CTD). Biochemical and genetic experiments demonstrate the importance of these regions, revealing the Vps11 CTD as a key integrator of Vps-C complex assembly, Rab signaling, and endosomal and lysosomal traffic.Keywords
This publication has 46 references indexed in Scilit:
- Identification of two evolutionarily conserved genes regulating processing of engulfed apoptotic cellsNature, 2010
- The CORVET Subunit Vps8 Cooperates with the Rab5 Homolog Vps21 to Induce Clustering of Late Endosomal CompartmentsMolecular Biology of the Cell, 2009
- HOPS Interacts with Apl5 at the Vacuole Membrane and Is Required for Consumption of AP-3 Transport VesiclesMolecular Biology of the Cell, 2009
- Vps-C complexes: gatekeepers of endolysosomal trafficCurrent Opinion in Cell Biology, 2009
- An experimentally derived confidence score for binary protein-protein interactionsNature Methods, 2008
- An empirical framework for binary interactome mappingNature Methods, 2008
- Efficient termination of vacuolar Rab GTPase signaling requires coordinated action by a GAP and a protein kinaseThe Journal of cell biology, 2008
- Reconstituted membrane fusion requires regulatory lipids, SNAREs and synergistic SNARE chaperonesThe EMBO Journal, 2008
- Rabs and their effectors: Achieving specificity in membrane trafficProceedings of the National Academy of Sciences of the United States of America, 2006
- Purification of active HOPS complex reveals its affinities for phosphoinositides and the SNARE Vam7pThe EMBO Journal, 2006