| Title : Ric-8B stabilizes the alpha subunit of stimulatory G protein by inhibiting its ubiquitination - Nagai_2010_J.Biol.Chem_285_11114 |
| Author(s) : Nagai Y , Nishimura A , Tago K , Mizuno N , Itoh H |
| Ref : Journal of Biological Chemistry , 285 :11114 , 2010 |
| Abstract : The alpha subunit of stimulatory G protein (G alpha(s)) activates adenylyl cyclase, which catalyzes cAMP production, and regulates many physiological aspects, such as cardiac regulation and endocrine systems. Ric-8B (resistance to inhibitors of cholinesterase 8B) has been identified as the G alpha(s)-binding protein; however, its role in G(s) signaling remains obscure. In this study, we present evidence that Ric-8B specifically and positively regulates G(s) signaling by stabilizing the G alpha(s) protein. An in vitro biochemical study suggested that Ric-8B does not possess guanine nucleotide exchange factor activity. However, knockdown of Ric-8B attenuated beta-adrenergic agonist-induced cAMP accumulation, indicating that Ric-8B positively regulates G(s) signaling. Interestingly, overexpression and knockdown of Ric-8B resulted in an increase and a decrease in the G alpha(s) protein, respectively, without affecting the G alpha(s) mRNA level. We found that the G alpha(s) protein is ubiquitinated and that this ubiquitination is inhibited by Ric-8B. This Ric-8B-mediated inhibition of G alpha(s) ubiquitination requires interaction between Ric-8B and G alpha(s) because Ric-8B splicing variants, which are defective for G alpha(s) binding, failed to inhibit the ubiquitination. Taken together, these results suggest that Ric-8B plays a critical and specific role in the control of G alpha(s) protein levels by modulating G alpha(s) ubiquitination and positively regulates G(s) signaling. |
| ESTHER : Nagai_2010_J.Biol.Chem_285_11114 |
| PubMedSearch : Nagai_2010_J.Biol.Chem_285_11114 |
| PubMedID: 20133939 |
Nagai Y, Nishimura A, Tago K, Mizuno N, Itoh H (2010)
Ric-8B stabilizes the alpha subunit of stimulatory G protein by inhibiting its ubiquitination
Journal of Biological Chemistry
285 :11114
Nagai Y, Nishimura A, Tago K, Mizuno N, Itoh H (2010)
Journal of Biological Chemistry
285 :11114