Phosphorylation of G Protein–Coupled Receptors: GPCR Kinases in Heart Disease

Abstract

In the heart, β -adrenergic receptors (β ARs), members of the superfamily of G protein–coupled receptors (GPCRs), modulate cardiac responses to catecholamines. β AR signaling, which is compromised in many cardiac diseases (e.g., congestive heart failure), is regulated by GPCR kinases (GRKs). Levels of the most abundant cardiac GRK, known as GRK2 or β AR kinase 1 (β ARK1), are increased in both animal and human heart failure. Transgenic mouse models have demonstrated that β ARK1 plays a vital role in cardiac function and development, as well as in the regulation of myocardial signaling, and pharmacological studies have further implicated GRKs in the impairment of cardiac GPCR signaling. Gene therapy, along with the development of small-molecule modulators of GRK activity, has indicated in multiple animal models that the manipulation of GRK activity may elicit therapeutic benefits in many forms of cardiac disease.