PKC-isoform specific regulation of receptor desensitization and KCNQ1/KCNE1 K channel activity by mutant α-adrenergic receptors.

Activation of a specific protein kinase C (PKC) isoform during stimulation of G protein-coupled receptors (GPCRs) is determined by homologous receptor desensitization that controls the spatiotemporal formation of downstream G signalling molecules. Furthermore, GPCR-activated PKC isoforms specifically regulate receptor activity via a negative feedback mechanism. In the present study, we investigated the contribution of several phosphorylation sites in the α-adrenergic receptor (α-AR) for PKC and G protein coupled receptor kinase 2 (GRK2) to homologous receptor desensitization and effector modulation.