Endothelin-1 induces p66Shc activation through EGF receptor transactivation: Role of beta(1)Pix/Galpha(i3) interaction.
Endothelin-1 (ET-1) is a vasoconstrictor peptide known to be a potent mitogen for glomerular mesangial cells. We have shown that ET-1 stimulates the adaptor protein p66Shc through Rac/Cdc42 guanine nucleotide exchange factor beta(1)Pix. In this study, we demonstrate that ET-1-induced serine phosphorylation of p66Shc is mediated through Galpha(i3). Pertussis toxin treatment of cells induced a significant decrease in the interaction between beta(1)Pix and ET(A)-R, and an increase in the binding of Galpha(i3) and G(beta1) to beta(1)Pix. Activation of heterotrimeric G proteins by AlF(4)(-) resulted in an increase of Galpha(i3) binding to beta(1)Pix, which was significantly disrupted in cells expressing beta(1)Pix dimerization deficient mutant, beta(1)PixDelta (602-611). In cells expressing beta(1)PixDelta (602-611), ET-1-induced p66Shc activation was also significantly decreased. Specific inhibition of EGF receptor by AG1478 blocked ET-1-induced p66Shc activation and the binding of p66Shc and Galpha(i3) to beta(1)Pix. Inhibition of Erk1/2 blocked p66Shc activation induced by ET-1. Altogether, our results indicate that ET-1 activates p66Shc through EGF receptor transactivation, leading to the activation of Galpha(i3), beta(1)Pix and Erk1/2.
Kidney Disease Center, Department of Medicine, Medical College of Wisconsin, Milwaukee, 53226, United States.
Ahmed
A
Chahdi
Andrey
A
Sorokin
D002478:Cells, Cultured; D019332:Endothelin-1 / Q000494:pharmacology*; D066246:ErbB Receptors / Q000378:metabolism*; D019206:GTP-Binding Protein alpha Subunits, Gi-Go / Q000378:metabolism*; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D037342:Pertussis Toxin / Q000494:pharmacology; D010766:Phosphorylation; D064067:Rho Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D055765:Shc Signaling Adaptor Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
C576606:ARHGEF7 protein, human; D019332:Endothelin-1; D020662:Guanine Nucleotide Exchange Factors; D064067:Rho Guanine Nucleotide Exchange Factors; D055765:Shc Signaling Adaptor Proteins; D037342:Pertussis Toxin; D066246:ErbB Receptors; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D019206:GTP-Binding Protein alpha Subunits, Gi-Go