Abstract
Rhodopsin phosphorylation and in consequence cGMP hydrolysis in bovine rod outer segments are Ca2+ dependent in the presence of ATP. The level of rhodopsin phosphorylation decreases and the lifetime of active phosphodiesterase increases when the free [Ca2+] is raised from < 1 nM to about 1 microM; in both cases the half-maximal effect was observed at 140-170 nM of free Ca2+. Antibodies to recoverin reverse both effects at high [Ca2+] but have no influence at low [Ca2+]. We conclude that the Ca2+ effects observed are mediated by recoverin which inhibits rhodopsin kinase at a high Ca2+ level.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Adenosine Triphosphate / metabolism
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Animals
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Antibodies, Monoclonal / metabolism
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Calcium / metabolism*
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Calcium-Binding Proteins / immunology
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Calcium-Binding Proteins / metabolism*
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Cattle
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Cyclic GMP / metabolism*
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Eye Proteins*
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G-Protein-Coupled Receptor Kinase 1
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Hippocalcin
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Lipoproteins*
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Nerve Tissue Proteins*
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Phosphorylation
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Protein Kinase Inhibitors
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Protein Kinases / metabolism
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Recoverin
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Retinal Rod Photoreceptor Cells / metabolism*
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Rhodopsin / metabolism*
Substances
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Antibodies, Monoclonal
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Calcium-Binding Proteins
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Eye Proteins
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Lipoproteins
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Nerve Tissue Proteins
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Protein Kinase Inhibitors
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Recoverin
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Hippocalcin
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Adenosine Triphosphate
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Rhodopsin
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Protein Kinases
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G-Protein-Coupled Receptor Kinase 1
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Cyclic GMP
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Calcium