RRC ID 46671
Author Porter MY, Xie K, Pozharski E, Koelle MR, Martemyanov KA.
Title A conserved protein interaction interface on the type 5 G protein beta subunit controls proteolytic stability and activity of R7 family regulator of G protein signaling proteins.
Journal J Biol Chem
Abstract Regulators of G protein signaling (RGS) proteins of the R7 subfamily limit signaling by neurotransmitters in the brain and by light in the retina. They form obligate complexes with the Gβ5 protein that are subject to proteolysis to control their abundance and alter signaling. The mechanisms that regulate this proteolysis, however, remain unclear. We used genetic screens to find mutations in Gβ5 that selectively destabilize one of the R7 RGS proteins in Caenorhabditis elegans. These mutations cluster at the binding interface between Gβ5 and the N terminus of R7 RGS proteins. Equivalent mutations within mammalian Gβ5 allowed the interface to still bind the N-terminal DEP domain of R7 RGS proteins, and mutant Gβ5-R7 RGS complexes initially formed in cells but were then rapidly degraded by proteolysis. Molecular dynamics simulations suggest the mutations weaken the Gβ5-DEP interface, thus promoting dynamic opening of the complex to expose determinants of proteolysis known to exist on the DEP domain. We propose that conformational rearrangements at the Gβ5-DEP interface are key to controlling the stability of R7 RGS protein complexes.
Volume 285(52)
Pages 41100-12
Published 2010-12-24
DOI 10.1074/jbc.M110.163600
PII S0021-9258(19)76276-0
PMID 20959458
PMC PMC3003408
MeSH Animals Caenorhabditis elegans / chemistry* Caenorhabditis elegans / genetics Caenorhabditis elegans / metabolism Caenorhabditis elegans Proteins / chemistry* Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism Computer Simulation* GTP-Binding Protein beta Subunits / chemistry* GTP-Binding Protein beta Subunits / genetics GTP-Binding Protein beta Subunits / metabolism HEK293 Cells Humans Models, Molecular* Multiprotein Complexes Mutation Protein Binding Protein Structure, Quaternary Protein Structure, Tertiary RGS Proteins / chemistry* RGS Proteins / genetics RGS Proteins / metabolism
IF 4.238
Times Cited 13
WOS Category BIOCHEMISTRY & MOLECULAR BIOLOGY
Resource
C.elegans tm761