A phosphorylation-sensitive anti-rhodopsin monoclonal antibody reveals light-induced phosphorylation of rhodopsin in the photoreceptor cell body.
Rho-1C5, a monoclonal antibody sensitive to phosphorylation of rhodopsin, bound to the retinal photoreceptor cell body region of dark-adapted but not light-adapted 8 to 13-day-old-rats. There was no cell body labeling visible either before or after this time, although the photoreceptor outer segments were labeled at all times from postnatal day 5 (PN5) onwards, in both light and dark adapted retinas. However, opsin was detectable in the photoreceptor cell body region from birth onwards using another rhodopsin antibody binding to a site unaffected by phosphorylation. Competitive inhibition radioimmunoassays also indicated light-dependent differences in Rho-1C5 binding at PN8 and adult. Biochemical studies showed light-dependent phosphorylation of rhodopsin at PN8, PN13 (just after eye opening) and adult. These data indicate that rhodopsin can be phosphorylated in a light-regulated manner early in development before eye opening and imply that photoactive chromophores can attach to opsin in the cell body as well as the outer segment.
Laboratory of Neurobiology, Rockefeller University, New York, NY.
D
D
Hicks
C J
CJ
Barnstable
D000818:Animals; D000911:Antibodies, Monoclonal; D001345:Autoradiography; D001667:Binding, Competitive; D007150:Immunohistochemistry; D010766:Phosphorylation; D010786:Photoreceptor Cells / Q000378:metabolism*; D011863:Radioimmunoassay; D051381:Rats; D012168:Retinal Pigments / Q000378:metabolism*; D012243:Rhodopsin / Q000276:immunology / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D012168:Retinal Pigments; D012243:Rhodopsin