Topography of the rhodopsin molecule. Identification of the domain phosphorylated.
Studies on the light-stimulated phosphorylation of rod outer segments by [gamma-32P]ATP showed that although nearly 1 mol of [32P]phosphate was incorporated/mol of total opsin, only a small fraction of the molecules were phosphorylated, and these contained at least 2-3 mol of phosphate/mol. Rod outer segments containing the phosphorylated opsin were incubated with 11-cis-retinal to generate phosphorylated rhodopsin and then digested with papain to produce a cleaved complex comprising three fragments, heavy (H), medium (M) and light (L). It was shown that L-fragment of apparent mol.wt. 6000 contained all the phosphorylation sites. This suggests that one specific domain of rhodopsin is susceptible to multiple phosphorylation.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002845:Chromatography; D004591:Electrophoresis, Polyacrylamide Gel; D008027:Light; D008956:Models, Chemical; D010206:Papain; D010766:Phosphorylation; D010786:Photoreceptor Cells / Q000378:metabolism*; D011487:Protein Conformation; D012168:Retinal Pigments / Q000378:metabolism*; D012172:Retinaldehyde / Q000378:metabolism; D012243:Rhodopsin / Q000378:metabolism*
D012168:Retinal Pigments; D000255:Adenosine Triphosphate; D012243:Rhodopsin; D010206:Papain; D012172:Retinaldehyde