RGS3 interacts with 14-3-3 via the N-terminal region distinct from the RGS (regulator of G-protein signalling) domain.
RGS3 belongs to a family of the regulators of G-protein signalling (RGS), which bind and inhibit the G alpha subunits of heterotrimeric G-proteins via a homologous RGS domain. Increasing evidence suggests that RGS proteins can also interact with targets other than G-proteins. Employing yeast two-hybrid screening of a cDNA library, ... we identified an interaction between RGS3 and the phosphoserine-binding protein 14-3-3. This interaction was confirmed by in vitro binding and co-immunoprecipitation experiments. RGS3-deletion analysis revealed the presence of a single 14-3-3-binding site located outside of the RGS domain. Ser(264) was then identified as the 14-3-3-binding site of RGS3. The S(264)A mutation resulted in the loss of RGS3 binding to 14-3-3, without affecting its ability to bind G alpha(q). Signalling studies showed that the S(264)A mutant was more potent than the wild-type RGS3 in inhibition of G-protein-mediated signalling. Binding experiments revealed that RGS3 exists in two separate pools, either 14-3-3-bound or G-protein-bound, and that the 14-3-3-bound RGS3 is unable to interact with G-proteins. These data are consistent with the model wherein 14-3-3 serves as a scavenger of RGS3, regulating the amounts of RGS3 available for binding G-proteins. This study describes a new level in the regulation of G-protein signalling, in which the inhibitors of G-proteins, RGS proteins, can themselves be regulated by phosphorylation and binding 14-3-3.
Mesh Terms:
14-3-3 Proteins, Animals, Binding Sites, CHO Cells, Cricetinae, DNA-Binding Proteins, Enzyme Inhibitors, GTP-Binding Proteins, GTPase-Activating Proteins, Gene Library, Genes, Reporter, Humans, Protein Binding, Protein Structure, Tertiary, Proto-Oncogene Proteins, RGS Proteins, Recombinant Fusion Proteins, Signal Transduction, Transcription Factors, Two-Hybrid System Techniques, Tyrosine 3-Monooxygenase, ets-Domain Protein Elk-1
14-3-3 Proteins, Animals, Binding Sites, CHO Cells, Cricetinae, DNA-Binding Proteins, Enzyme Inhibitors, GTP-Binding Proteins, GTPase-Activating Proteins, Gene Library, Genes, Reporter, Humans, Protein Binding, Protein Structure, Tertiary, Proto-Oncogene Proteins, RGS Proteins, Recombinant Fusion Proteins, Signal Transduction, Transcription Factors, Two-Hybrid System Techniques, Tyrosine 3-Monooxygenase, ets-Domain Protein Elk-1
Biochem. J.
Date: Aug. 01, 2002
PubMed ID: 11985497
View in: Pubmed Google Scholar
Download Curated Data For This Publication
10303
Switch View:
- Interactions 3