Calcium promotes cell survival through CaM-K kinase activation of the protein-kinase-B pathway
Calcium promotes cell survival through CaM-K kinase activation of the protein-kinase-B pathway
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DOI：
10.1038/25147
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发表时间：
1998-12-10
期刊：
影响因子：
64.8
通讯作者：
Sodeling, TR
中科院分区：
文献类型：
--
作者：
Yano, S;Tokumitsu, H;Sodeling, TR
The protection against apoptosis provided by growth factors in several cell lines is due to stimulation of the phosphatidylinositol-3-OH kinase (PI(3)K) pathway, which results in activation of protein kinase B-1,B-2 (PKB; also known as c-Akt and Rac) and phosphorylation and sequestration to protein 14-3-3 of the pro-apoptotic Bcl-2-family member BAD(3-7). A modest increase in intracellular Ca2+ concentration also promotes survival of some cultured neurons(8,9) through a pathway that requires calmodulin but is independent of PI(3)K and the MAP kinases(10,11), Here we report that Ca2+/calmodulin-dependent protein kinase kinase (CaM-KK) activates PKB directly, resulting in phosphorylation of BAD on serine residue 136 and the interaction of BAD with protein 14-3-3, Serum withdrawal induced a three- to fourfold increase in cell death of NG108 neuroblastoma cells, and this apoptosis was largely blocked by increasing the intracellular Ca2+ concentration with NMDA (N-methyl-D-aspartate) or KCl or by transfection with constitutively active CaM-KK. The effect of NMDA on cell survival was blocked by transfection with dominant-negative forms of CaM-KK or PKB. These results identify a Ca2+-triggered signalling cascade in which CaM-KK activates PKB, which in turn phosphorylates BAD and protects cells from apoptosis.
