Light-stimulated protein movement in rod photoreceptor cells of the rat retina.
We examined the intracellular distribution of three proteins involved in the cyclic GMP cascade of visual transduction; cGMP phosphodiesterase, the alpha-subunit of G-protein and arrestin. In adult rats, light-induced changes in the amounts of G and arrestin in the photoreceptor cell outer segments were observed both by polyacrylamide gel analysis of purified ROS and by immunocytochemical localization on retinal sections. In dark conditions, G was concentrated in the outer segments of photoreceptor cells while in the light G alpha was seen in the inner segments and the outer nuclear layer. Arrestin had the opposite distribution, appearing in the inner segments and outer nuclear layer under dark conditions and in the ROS under light conditions. In contrast, PDE, the enzyme which is activated by G and inhibited by arrestin showed no light-stimulated movement. In both light- and dark-adapted retinas, PDE was localized primarily in the outer segments of the photoreceptor cells.
Philp
N J
NJ
Department of Anatomy, School of Medicine, University of Pennsylvania, Philadelphia 19104.
Chang
W
W
Long
K
K
D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000378:metabolism*; D000818:Animals; D000941:Antigens / Q000378:metabolism*; D019393:Arrestin; D003623:Dark Adaptation; D004591:Electrophoresis, Polyacrylamide Gel; D005136:Eye Proteins / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D007124:Immunoenzyme Techniques; D008027:Light; D008297:Male; D010786:Photoreceptor Cells / Q000378:metabolism* / Q000528:radiation effects; D051381:Rats; D011919:Rats, Inbred Strains; D012374:Rod Cell Outer Segment / Q000378:metabolism* / Q000528:radiation effects
D000941:Antigens; D019393:Arrestin; D005136:Eye Proteins; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D019204:GTP-Binding Proteins