G-Protein-Coupled Receptor Kinase 1 (GRK1)
The activity of G-protein-coupled receptor kinase 1 (GRK1) was first observed in the light-dependent phosphorylation of rhodopsin in rod outer segment (ROS). As GRK1 was unstable during biochemical manipulations, isolating it in sufficient quantity and quality was proven to be difficult over a period of 30 years (Maeda et al. 2003). The GRK1 gene was cloned in the early 1990s (Lorenz et al. 1991), and many findings regarding its roles in phototransduction recovery, light and dark adaptation, and stationary night blindness of human Oguchi disease took place in the following decade (Chen et al. 1999; Lyubarsky et al. 2000; Khani et al. 1998; Cideciyan et al. 1998). GRK1 is posttranslationally modified by isoprenylation and phosphorylation, and its catalytic activity can be regulated by other proteins such as recoverin (Chen et al. 1995) and protein kinase A (Horner et al. 2005). It...