Research ArticleG Protein Signaling

Dual phosphorylation of Ric-8A enhances its ability to mediate G protein α subunit folding and to stimulate guanine nucleotide exchange

See allHide authors and affiliations

Science Signaling  29 May 2018:
Vol. 11, Issue 532, eaap8113
DOI: 10.1126/scisignal.aap8113

Phosphorylating a chaperone

Heterotrimeric G proteins, which consist of various combinations of α, β, and γ subunits, transduce a wide array of signals from G protein–coupled receptors (GPCRs). Proteins of the Ric-8 family are molecular chaperones that are required for the proper folding of Gα subunits and their assembly with βγ dimers to form functional G proteins. Papasergi-Scott et al. found that Ric-8A was itself regulated through the CK2-mediated phosphorylation of two serine and threonine residues that are conserved from worms to humans. Worms engineered to express a mutant Ric-8 protein deficient in these conserved sites exhibited defective locomotion and egg laying, functions that depend on G protein activation. Together, these data suggest that dual phosphorylation of Ric-8A is required for effective Gα subunit folding and activity.

View Full Text

Stay Connected to Science Signaling