Fonction des chaperonnes moléculaires dans l'assemblage des protéines G hétérotrimériques

Extracellular signals received by G protein-coupled receptors (GPCRs) are transduced into intracellular responses following the activation of heterotrimeric G proteins. As their names suggests, they are composed of three subunits, Gα and Gβγ, the latter being effectively treated as a single entity. The Gβγ dimer is assembled with the aid of a number of molecular chaperones in a tightly regulated process. The folding of nascent Gβ₁ is favoured by cellular chaperones such as PhLP-1 and CCT and the ER-resident protein DRiP78 plays an important role in the stability of nascent Gγ₂ subunits. However, much work remains to be done to completely understand the mechanisms underlying assembly of the heterotrimer.