Stereospecific inositol 1,4,5-[32P]trisphosphate binding to isolated rat liver nuclei: evidence for inositol trisphosphate receptor-mediated calcium release from the nucleus.
It is well known that inositol 1,4,5-trisphosphate binding and release of calcium are mediated by the same protein. Several reports have indicated the location of the inositol 1,4,5-trisphosphate receptor in organelles other than endoplasmic reticulum. Immunocytochemical studies on the subcellular localization of 1,4,5-trisphosphate receptor in the Purkinje cells from two laboratories have given contradictory results regarding the nuclear location of this receptor. In this paper, a high-affinity inositol 1,4,5-[32P]trisphosphate binding site (Kd = 0.11 nM) on nuclei isolated from rat liver and devoid of any microsomal, mitochondrial, or plasma membrane constituents is documented. Furthermore, we present data demonstrating that inositol 1,4,5-trisphosphate is capable of releasing 45Ca2+ from the intact isolated liver nuclei. A rapid and transient release of calcium that was taken up by nuclei in the presence of ATP is observed. The role of inositol 1,4,5-trisphosphate in the coupling between cytoplasmic second messengers and nuclear events activated during signal transduction is postulated.
Malviya
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Centre de Neurochimie, Centre National de la Recherche Scientifique, Strasbourg, France.
Rogue
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Vincendon
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D000818:Animals; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism*; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism* / Q000494:pharmacology; D053496:Inositol 1,4,5-Trisphosphate Receptors; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008862:Microsomes, Liver / Q000378:metabolism; D009251:NADPH-Ferrihemoprotein Reductase / Q000378:metabolism; D010761:Phosphorus Radioisotopes; D051381:Rats; D011956:Receptors, Cell Surface / Q000378:metabolism* / Q000502:physiology; D018160:Receptors, Cytoplasmic and Nuclear; D015290:Second Messenger Systems; D015398:Signal Transduction
D015220:Calcium Channels; D053496:Inositol 1,4,5-Trisphosphate Receptors; D010761:Phosphorus Radioisotopes; D011956:Receptors, Cell Surface; D018160:Receptors, Cytoplasmic and Nuclear; D015544:Inositol 1,4,5-Trisphosphate; D009251:NADPH-Ferrihemoprotein Reductase; D002118:Calcium