beta-arrestin-mediated recruitment of the Src family kinase yes mediates endothelin-1-stimulated glucose transport

The insulin and the endothelin type A (ETA) receptor both can couple into t he heterotrimeric G protein alpha (q/11) (G alpha (q/11)), leading to G alp ha (q/11) tyrosine phosphorylation, phosphatidylinositol 3-kinase activatio n, and subsequent stimulation of glucose transport. In this study, we asses sed the potential role of Src kinase in ET-1 signaling to glucose transport in 3T3-L1 adipocytes. Src kinase inhibitor PP2 blocked ET-1-induced Src ki nase activity, G alpha (q/11) tyrosine phosphorylation, and glucose transpo rt stimulation. To determine which Src family kinase member was involved, w e microinjected anti-c-Src, -c-Fyn, or -c-Yes antibody into these cells and found that only anti-e-Yes antibody blocked GLUT4 translocation (70% decre ased). Overexpression or microinjection of a dominant negative mutant (K298 M) of Src kinase also inhibited ET-1-induced Ga,,,, tyrosine phosphorylatio n and GLUT4 translocation. In co-immunoprecipitation experiments, we found that beta -arrestin 1 associated with the ETA receptor in an agonist-depend ent manner and that beta -arrestin 1 recruited Src kinase to a molecular co mplex that included the ETA receptor. Microinjection of beta -arrestin 1 an tibody inhibited ET-1- but not insulin-stimulated GLUT4 translocation. In c onclusion, 1) the Src kinase Yes can induce tyrosine phosphorylation of G a lpha (q/11) in response to ET-1 stimulation, and 2) beta -arrestin I and Sr c kinase form a molecular complex with the ETA receptor to mediate ET-1 sig naling to G alpha (q/11) with subsequent glucose transport stimulation.