Chicken red-sensitive cone visual pigment retains a binding domain for transducin.
Iodopsin (a red-sensitive cone visual pigment) and rhodopsin (a rod pigment) were isolated from chicken retina. They were separately reconstituted into phosphatidylcholine liposomes and then mixed with rod transducin (T alpha and T beta gamma) purified from bovine retina. Iodopsin enhanced, only when irradiated, the binding of GppNHp to T alpha to a similar extent to irradiated rhodopsin. Furthermore, the binding of GppNHp to T alpha in the presence of a photobleaching intermediate of iodopsin preferably required T beta gamma-2 rather than T beta gamma-1, which is very similar in profile to that in the presence of the intermediate of rhodopsin (J. Biol. Chem., in press). These results indicate that the binding domain for transducin in iodopsin should closely resemble that in rhodopsin.
Fukada
Y
Y
Department of Biophysics, Faculty of Science, Kyoto University, Japan.
Okano
T
T
Artamonov
I D
ID
Yoshizawa
T
T
D000818:Animals; D001665:Binding Sites; D002384:Catalysis; D002645:Chickens; D004591:Electrophoresis, Polyacrylamide Gel; D006165:Guanylyl Imidodiphosphate / Q000378:metabolism; D008027:Light; D008081:Liposomes / Q000378:metabolism; D046911:Macromolecular Substances; D010713:Phosphatidylcholines; D012160:Retina / Q000032:analysis*; D012168:Retinal Pigments / Q000378:metabolism* / Q000528:radiation effects; D012243:Rhodopsin / Q000378:metabolism* / Q000528:radiation effects; D017299:Rod Opsins; D015293:Transducin / Q000378:metabolism*
D008081:Liposomes; D046911:Macromolecular Substances; D010713:Phosphatidylcholines; D012168:Retinal Pigments; D017299:Rod Opsins; C034941:iodopsin; D006165:Guanylyl Imidodiphosphate; D012243:Rhodopsin; D015293:Transducin