GRK2, or Adrenergic, beta, receptor kinase 1, is a human gene encoded by ADRBK1. It may also be known as: Beta-adrenergic receptor kinase 1; Beta-ARK-1; G-protein coupled receptor kinase 2; BARK1; BETA-ARK1. The encoded protein is an enzyme with an amino acid length of 689 and a mass of 79.6 kDa. GRK2 is a member of the Protein kinase superfamily, AGC Ser/Thr protein kinase family, GPRK subfamily. Homologs of this gene exist in other organisms, including: Mouse, Rat.