Abstract
We report the stoichiometric phosphorylation of an inositol 1,4,5-trisphosphate receptor-binding protein from rat brain by the cAMP-dependent protein kinase but not by protein kinase C or Ca2+/calmodulin-dependent protein kinase. This phosphorylation event does not markedly alter [3H]inositol 1,4,5-trisphosphate-binding characteristics. However, inositol 1,4,5-trisphosphate is only 10% as potent in releasing 45Ca2+ from phosphorylated, as compared with native, cerebellar microsomes. Phosphorylation of the inositol 1,4,5-trisphosphate-binding protein by the cAMP-dependent protein kinase may provide a biochemical substrate for second-messenger cross talk.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Brain / metabolism*
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Calcium / metabolism*
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Calcium Channels*
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Inositol 1,4,5-Trisphosphate Receptors
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Inositol Phosphates / physiology*
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Kinetics
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Microsomes / metabolism*
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Organ Specificity
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Phosphorylation
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Protein Kinases / metabolism*
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Rats
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Rats, Inbred Strains
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Receptors, Cell Surface / metabolism*
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Receptors, Cell Surface / physiology
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Receptors, Cytoplasmic and Nuclear*
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Sugar Phosphates / physiology*
Substances
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Calcium Channels
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Inositol 1,4,5-Trisphosphate Receptors
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Inositol Phosphates
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Receptors, Cell Surface
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Receptors, Cytoplasmic and Nuclear
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Sugar Phosphates
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Protein Kinases
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Calcium