G protein-coupled receptor kinase 2 (GRK2)

G protein-coupled receptor kinase 2 (GRK2) is a serine/threonine kinase of the AGC kinase superfamily, primarily known for phosphorylating activated G protein-coupled receptors (GPCRs). Phosphorylation of GPCRs by GRK2 triggers the recruitment of arrestins, promoting receptor desensitization and internalization, thereby modulating receptor signaling intensity and duration. GRK2 also interacts with non-receptor proteins, influencing cell migration, cell cycle regulation, apoptotic processes, and extracellular matrix dynamics. It plays essential roles in many tissues—most significantly in the cardiovascular system—where elevated GRK2 activity is linked to heart failure, hypertension, and fibrosis. As a result, GRK2 is recognized as a validated therapeutic target, with several small molecule inhibitors (notably paroxetine) and experimental genetic or peptide approaches under investigation for treating heart failure, fibrotic, and inflammatory diseases. However, the development of selective modulators remains a challenge given GRK2’s broad role in multiple physiological pathways[1][2][3][4][5][6][7].

Other names

Beta-adrenergic receptor kinase 1Beta-ARK1ADRBK1BARK1

Small molecules (e.g., paroxetine) bind to GRK2, inhibiting its kinase activity, which prevents phosphorylation of activated GPCRs and alters downstream signaling, offering potential reversal of receptor desensitization and heart failure phenotypes[4][7]. Peptide or gene therapy approaches block membrane localization or protein-protein interaction domains of GRK2 to inhibit function[5].