G Protein Coupled Receptor Kinase 4 (GRK4)

G protein-coupled receptor kinase 4 is a member of the guanine nucleotide-binding protein (G protein)-coupled receptor kinase subfamily of the Ser/Thr protein kinase family. The protein phosphorylates the activated forms of G protein-coupled receptors thus initiating its deactivation. This gene has been linked to both genetic and acquired hypertension. G protein-coupled receptor kinases are a family of serine/threonine kinases that appear to play a role in receptor desensitization. Beta-adrenergic receptor kinase-1 and rhodopsin kinase are examples. They phosphorylate the activated form of the corresponding receptor, increasing its ability to interact with beta-arrestin or retinal arrestin, respectively. Binding of the arrestins to the receptors then blocks further activation of the respective signal transduction pathways.