In bovine experiments, phosphorylation of RGS9-1 (at Ser475, human site predicted to be at Ser478) by protein kinase C (PRKC, specifically the isozymes PRKCalpha and PRKCtheta) significantly decreased the affinity of RGS9-1 for its membrane anchor protein and GAP enhancer RGS9-1 anchor protein (R9S9BP). This represents a potential mechanism for feedback control of the photoresponse recovery in both rods and cones (Sokal et al. 2003, Balasubramanian et al. 2001, Hu et al. 2001).