The inositol (1,4,5)-trisphosphate 3-kinase of Xenopus oocyte is activated by CaMKII and involved in the regulation of InsP 3-mediated Ca 2+ release

• Published in: FEBS letters Vol. 449; no. 1; pp. 71 - 74
• Main Authors: Hague, Frédéric, Matifat, Fabrice, Brûlé, Gérard, Collin, Thibault
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 16.04.1999
• Subjects: Ca 2+ release; CaMKII; InsP 3 3-kinase; Xenopus oocyte; InsP 3 3-kinase; OA, okadaic acid; InsP 3, d-myo-inositol (1,4,5)-trisphosphate; CaM, calmodulin; Ca 2+ release; I Cl(Ca), calcium-dependent chloride current; CaMKII(290–309), CaMKII fragment 290–309; CaMKII, Ca 2+/CaM-dependent protein kinase II; CaMKII; InsP 4, d-myo-inositol (1,3,4,5)-tetrakisphosphate; InsP 1, d-myo-inositol -phosphate; RS20, myosin light chain kinase fragment 488–511; InsP 2, d-myo-inositol (1,4)-biphosphate; LPA, l-α lysophosphatidic acid oleyl; Xenopus oocyte
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(99)00399-3

The effect of Ca 2+ on inositol (1,4,5)-trisphosphate 3-kinase (3-kinase) activity was measured on Xenopus oocyte cytosolic extracts. The Ca 2+-evoked elevation in 3-kinase activity appeared to be mediated by calmodulin (CaM) and the calmodulin-dependent protein kinase II (CaMKII). The results observed in vitro were totally retrieved in intact oocytes and tend to demonstrate the involvement of a CaMKII-mediated phosphorylation in the regulation of 3-kinase activity. Finally, electrophysiological recordings of InsP 3-elicited chloride current transients in the presence of CaM/CaMKII inhibitors allowed to postulate an involvement of 3-kinase activity in the regulation of InsP 3-mediated Ca 2+ release.