Rapid agonist-induced beta-adrenergic receptor kinase translocation in C6 glioma cells.

Exposure of C6 glioma cells to 1 microM isoproterenol leads to fast desensitization of the beta-adrenergic receptor/adenylyl cyclase system and transient receptor sequestration. It also triggers a very rapid and transient translocation to the plasma membrane of beta-adrenergic receptor kinase (beta ARK), a specific cytoplasmic kinase that phosphorylates only the agonist-occupied form of several G protein-coupled receptors. beta ARK-mediated receptor phosphorylation appears to be a suitable mechanism for the rapid regulation of adrenergic receptor function in the nervous tissue.