Journal
JOURNAL OF BIOLOGICAL CHEMISTRY
Volume 277, Issue 51, Pages 49888-49895Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
DOI: 10.1074/jbc.M202755200
Keywords
-
Categories
Funding
- NEI NIH HHS [EY 100291] Funding Source: Medline
Ask authors/readers for more resources
A yeast two-hybrid approach was used to discern possible new effectors for the betagamma subunit of heterotrimeric G proteins. Three of the clones isolated are structurally similar to Gbeta, each exhibiting the WD40 repeat motif. Two of these proteins, the (r) under bar eceptor for (a) under bar ctivated (C) under bar (k) under bar inase 1 (RACK1) and the dynein intermediate chain, coimmunoprecipitate with Gbetagamma using an anti-Gbeta antibody. The third protein, AAH20044, has no known function; however, sequence analysis indicates that it is a WD40 repeat protein. Further investigation with RACK1 shows that it not only interacts with Gbeta(1)gamma(1) but also unexpectedly with the transducin heterotrimer Galpha(t)beta(1)gamma(1). Gat alone does not interact, but it must contribute to the interaction because the apparent EC50 value of RACK1 for Galpha(t)beta(1)y(1) is 3-fold greater than that for Gbeta(1)gamma(1) (0.1 versus 0.3 muM). RACK1 is a scaffold that interacts with several proteins, among which are activated betaIIPKC and dynamin-1 (1). betaIIPKC and dynamin-1 compete with Gbeta(1)gamma(1) and Galpha(t)beta(1)gamma(1) for interaction with RACK1. These findings have several implications: 1) that WD40 repeat proteins may interact with each other; 2) that Gbetagamma interacts differently with RACK1 than with its other known effectors; and/or 3) that the G protein-RACK1 complex may constitute a signaling scaffold important for intracellular responses.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available