Regulator of G protein signaling domain (RGS) found in G protein-coupled receptor kinase 2 (GRK2) and G protein-coupled receptor kinase 3 (GRK3)
The RGS domain is an essential part of the GRK2 (G protein-coupled receptor kinases 2) and the GRK3 proteins, which are members of the beta-adrenergic receptor kinases subfamily. GRK2 and GRK3 are ubiquitously expressed and can phosphorylate many different GPCR. The C-terminus of GRK2 and 3 contains a plekstrin homology domain (PH) with binding sites for the membrane phospholipid PIP2 and free G#? subunits. These specific interactions could help to maintain a membrane-bound population of GRK2 prior to the agonist-dependent overt GRK2 translocation. GRK2 and GRK3 are members of the GRK kinase family which includes three major subfamilies: the GRK4 subfamily (GRK4, GRK5 and GRK6), the rhodopsin kinase or visual GRK subfamily (GRK1 and GRK7), and the beta-adrenergic receptor kinases subfamily (GRK2/GRK3). The RGS domain of the GRKs has very little sequence similarity with the canonical RGS domain of the RGS proteins and therefore is often refered to as the RH (RGS Homology) domain. RGS proteins regulate many aspects of embryonic development such as glial differentiation, embryonic axis formation, skeletal and muscle development, cell migration during early embryogenesis, as well as apoptosis, cell proliferation, and modulation of cardiac development.
Jiyao W et al.(2023). "The conserved domain database in 2023.",