GRK5 is required for adipocyte differentiation through ERK activation.

Previous studies have identified G protein-coupled receptor (GPCR) kinase 5 (GRK5) as a genetic factor contributing to obesity pathogenesis, but the underlying mechanism remains unclear. We demonstrate here that Grk5 mRNA is more abundant in stromal vascular fractions of mouse white adipose tissue, the fraction that contains adipose progenitor cells, or committed pre-adipocytes, than in adipocyte fractions. Thus, we generated a GRK5 knockout (KO) 3T3-L1 pre-adipocyte to further investigate the mechanistic role of GRK5 in regulating adipocyte differentiation.