G Protein Coupled Receptor Kinase 1 (GRK1)

Light-dependent deactivation of rhodopsin as well as homologous desensitization of beta-adrenergic receptors involves receptor phosphorylation that is mediated by the highly specific protein kinases rhodopsin kinase (RHOK, or GRK1) and beta-adrenergic receptor kinase (BARK, or ADRBK1), respectively. Lorenz et al. (1991) cloned a cDNA for RHOK. The deduced amino acid sequence showed a high degree of homology to the beta-adrenergic receptor kinase. From similarities to cyclic nucleotide-dependent protein kinase and protein kinase C, they concluded that RHOK and BARK are members of a newly delineated gene family of guanine nucleotide-binding protein (G protein)-coupled receptor kinases that may function in diverse pathways to regulate the function of such receptors.