Abstract 15544: GRK2 RGS Domain-Specific Interaction With Gαq Inhibits Hypertrophy and Cardiac Dysfunction During Pressure Overload

G protein-coupled receptor (GPCR) kinases (GRK) play a critical role in cardiac function through regulation of GPCR activity. Canonically, GRK2 phosphorylates active GPCRs leading to desensitization and down-regulation of the receptors to regulate signaling in the heart. Mounting evidence, however, supports non-canonical regulation of cardiac function by GRK2 through a dynamic “interactome” in which GRK2 can uncouple GPCRs via novel protein-protein interactions. Several GRK2 interacting partners are important for adaptive and maladaptive myocyte growth including Gq, the signaling trigger for maladaptive cardiac hypertrophy, leading to HF. Importantly, GRK2 contains a putative amino-terminal Regulator of G protein Signaling (RGS) domain, that directly interacts with Gq and appears to inhibit signaling without altering Gq enzymatic activity. In the present study we generated transgenic (Tg) mice with cardiac-specific expression of the RGS domain of GRK2 (βARKrgs) and subjected them to a trans-aortic constri...