Cyclic AMP-dependent phosphorylation of a brain inositol trisphosphate receptor decreases its release of calcium.
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.
Supattapone
S
S
Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Danoff
S K
SK
Theibert
A
A
Joseph
S K
SK
Steiner
J
J
Snyder
S H
SH
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007295:Inositol Phosphates / Q000502:physiology*; D007700:Kinetics; D008861:Microsomes / Q000378:metabolism*; D009928:Organ Specificity; D010766:Phosphorylation; D011494:Protein Kinases / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011956:Receptors, Cell Surface / Q000378:metabolism* / Q000502:physiology; D018160:Receptors, Cytoplasmic and Nuclear; D013403:Sugar Phosphates / Q000502:physiology*
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007295:Inositol Phosphates; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D013403:Sugar Phosphates; D011494:Protein Kinases; D002118:Calcium