RRC ID 28673
Author Sato K, Nakano A.
Title Dissection of COPII subunit-cargo assembly and disassembly kinetics during Sar1p-GTP hydrolysis.
Journal Nat Struct Mol Biol
Abstract COPII coat proteins are required for direct capture of cargo and SNARE proteins into transport vesicles from the endoplasmic reticulum (ER). Cargo and SNARE capture occurs during the formation of a 'prebudding complex' comprising a cargo, Sar1p-GTP and the COPII subunits Sec23/24p. The assembly and disassembly cycle of the prebudding complex on ER membranes is coupled to the Sar1p GTPase cycle. Using FRET to monitor a single round of Sec23/24p binding and dissociation from SNAREs in reconstituted liposomes, we show that Sec23/24p dissociates from v-SNARE and complexed t-SNARE with kinetics slower than Sar1p-GTP hydrolysis. Once Sec23/24p becomes associated with v-SNARE or complexed t-SNARE, the complex remains assembled during multiple rounds of Sar1p-GTP hydrolysis mediated by the GDP-GTP exchange factor Sec12p. These data suggest a model for the maintenance of kinetically stable prebudding complexes during the Sar1p GTPase cycle that regulates cargo sorting into transport vesicles.
Volume 12(2)
Pages 167-74
Published 2005-2-1
DOI 10.1038/nsmb893
PII nsmb893
PMID 15665868
MeSH COP-Coated Vesicles / metabolism* Fluorescence Resonance Energy Transfer GTP Phosphohydrolases / metabolism GTPase-Activating Proteins Guanine Nucleotide Exchange Factors Guanosine Diphosphate / metabolism Guanosine Triphosphate / metabolism* Hydrolysis Kinetics Liposomes / metabolism Membrane Glycoproteins / metabolism Membrane Proteins / metabolism Monomeric GTP-Binding Proteins / metabolism* Protein Subunits / metabolism Saccharomyces cerevisiae / genetics Saccharomyces cerevisiae / metabolism Saccharomyces cerevisiae Proteins / metabolism* Time Factors Vesicular Transport Proteins
IF 11.98
Times Cited 95
DNA material pKSY193 (RDB08689) pKSY197 (RDB08690) pKSY198 (RDB08691) pET21a-SED5 (RDB08692) pKSE165 (RDB08708) pKSE168 (RDB08709) pKSE174 (RDB08710) pKSE176 (RDB08711) pKSE188 (RDB08712) pKSE203 (RDB08713)