Enhanced expression of G protein-coupled receptor kinase 2 selectively increases the sensitivity of A_2A adenosine receptors to agonist-induced desensitization

摘要

G protein-couple receptor kinases(GRK_s) are thought to be important in mediating the agoist- induced phosphorylation and consequent desensitization of G protein-coupled receptor(GPCR) responses. We have previously shown that stable expression of a dominant negative mutant G protein- coupled receptor kinase 2 (GRK_2) construct in NG108-15 mouse neuroblastoma x rat glioma cells suppresses the agonist-induced desensitization of A_2A and A_2B adenosine receptor-stimulated adenylyl cyclase activity(Mundell et al., 1997). To further determine the role of GRK2 in agonist-induced desensitization of these adenosine receptors, we stably overexpressed wild type GRK2 in NG108-15 cells.