A 52 kD cytoskeletal protein from retinal rod photoreceptors is related to erythrocyte dematin.
A novel cytoskeletal antigen, RET52, has been identified in the mouse retina. This 52 kD polypeptide is antigenically related to dematin (band 4.9), an actin-bundling phosphoprotein component of the erythrocyte membrane skeleton. Like dematin, RET52 is also a substrate for cAMP-dependent protein kinase. Within the retina, RET52 is primarily concentrated in two regions-the rod inner segment and the outer synaptic layers-although the developmental expression of RET52 differs in these areas. RET52 is present at birth in the inner segment, but appears about the time of initial synapse formation (postnatal day 4-6) in the outer plexiform layer. No differences in RET52 expression have been detected in early-stage mouse retinas with the retinal degeneration (rd) phenotype. RET52 localization, developmental expression, homologies to dematin, and in vitro phosphorylation pattern suggest a possible role for cytoskeleton-associated proteins in the initiation or control of disk membrane assembly and/or synapse formation in the rod photoreceptor.
Roof
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D
Berman-Gund Laboratory, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston 02114.
Hayes
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A
Hardenbergh
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G
Adamian
M
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001798:Blood Proteins / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D015153:Blotting, Western; D003429:Cross Reactions / Q000276:immunology; D003598:Cytoskeletal Proteins / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005136:Eye Proteins / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D005455:Fluorescent Antibody Technique; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008817:Mice, Mutant Strains; D008970:Molecular Weight; D010750:Phosphoproteins; D010766:Phosphorylation; D010786:Photoreceptor Cells / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D011494:Protein Kinases / Q000378:metabolism; D012162:Retinal Degeneration / Q000378:metabolism
D000911:Antibodies, Monoclonal; D001798:Blood Proteins; D003598:Cytoskeletal Proteins; C489041:Dmtn protein, mouse; D005136:Eye Proteins; D010750:Phosphoproteins; D011494:Protein Kinases