Cyclic nucleotides and GTP analogues stimulate light-induced phosphorylation of octopus rhodopsin

AbstractLight-induced phosphorylation of octopus rhodopsin in microvillar membrane was shown to be stimulated by cyclic nucleotides in contrast to vertebrate rhodopsin kinase. Non-hydrolyzable GTP analogues, GTPγS and GppNHp, greatly enhanced the light-induced phosphorylation of octopus rhodopsin, but the non-hydrolyzable GDP analogue, GDPβS, was not effective. These results suggest that rhodopsin A-kinase is involved in regulating the interaction between rhodopsin and G-protein in octopus photoreceptors.Rhodopsin; Rhodopsin kinase; Kinase, A-; Protein, G-; Photoreceptor; (Octopus, Invertebrate