|
[摘要]:Prolonged (12 h) exposure of SH-SY5Y neuroblastoma cells to the mu-opioid receptor (MOPr) agonist [D-Ala(2), N-Me-Phe(4), Gly(5)-ol]-enkephalin (DAMGO) causes homologous desensitization as well as heterologous desensitization of the extracellular signal-regulated kinase 1/2 (ERK 1/2) phosphorylation induced by insulin-like growth factor (IGF)-I. Brief (15 min) but not prolonged exposure to DAMGO transregulates the insulin-like growth factor-I (IGF-I) receptor, as evidenced by its phosphorylation in the absence of IGF-I. Silencing of beta-arrestin 2 uncouples the crosstalk between the two receptors, thus maintaining IGF-I-mediated receptor phosphorylation and ERK 1/2 activation even after prolonged DAMGO exposure. Furthermore, MOPr-induced activation of IGF-I receptor requires the tyrosine kinase c-Src. (C) 2010 Federation of European Biochemical Societies. Published by Elsevier B. V. All rights reserved. |
|