D-myo-inositol 1,4,5-trisphosphate 3-kinase A is activated by receptor activation through a calcium:calmodulin-dependent protein kinase II phosphorylation mechanism
D-myo-inositol 1,4,5-trisphosphate 3-kinase A is activated by receptor activation through a calcium:calmodulin-dependent protein kinase II phosphorylation mechanism
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DOI：
10.1093/emboj/16.8.1943
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发表时间：
1997-04-15
期刊：
影响因子：
11.4
通讯作者：
Erneux, C
中科院分区：
文献类型：
--
作者：
Communi, D;Vanweyenberg, V;Erneux, C
d -肌醇1,4,5-三磷酸[Ins(1,4,5)P-3] 3-激酶是负责产生d -肌醇1,3,4,5-四磷酸的酶，在与乙醇孵育后的大鼠大脑皮质切片匀浆中被激活3至5倍。这种效应在过表达Ins(1,4,5)P-3 -激酶A的中国仓鼠卵巢（CHO）细胞中重现，Ins(1,4,5)P-3 -激酶A是大鼠和人类神经元细胞中存在的主要亚型。在正交p -32标记的细胞中，通过免疫沉淀激活受体后，可以鉴定出磷酸化的53 kDa酶，磷酸化的时间过程与氨基丁醇（或UTP）诱导的酶激活非常相似。在冈田酸的存在下，酶的磷酸化被阻止。钙调素（CaM）激酶II抑制剂（即KN-93和KN-62）阻止Zns(1,4,5)P-3激酶的磷酸化。对转染CHO细胞磷酸化位点的鉴定表明，磷酸化残基为Thr311。人脑序列的这一残基位于与CaM激酶ii介导的磷酸化一致位点（即Arg-Ala-Val-Thr）对应的活性位点肽段。Ins(1,4,5)P-3 3-激酶A中的相同残基也在体外被CaM激酶II磷酸化，磷酸化导致8- 10倍的酶激活和25倍的Ca2+:CaM复合物敏感性增加。本研究为Ins(1,4,5)P-3 s激酶（异构体a）在体外和完整细胞中的新调控机制提供了直接证据。
D-myo-inositol 1,4,5-trisphosphate [Ins(1,4,5)P-3] 3-kinase, the enzyme responsible for production of D-myoinositol 1,3,4,5-tetrakisphosphate, was activated 3- to 5-fold in homogenates of rat brain cortical slices after incubation with carbachol. The effect was reproduced in response to UTP in Chinese hamster ovary (CHO) cells overexpressing Ins(1,4,5)P-3 3-kinase A, the major isoform present in rat and human neuronal cells, In ortho-P-32-labelled cells, the phosphorylated 53 kDa enzyme could be identified after receptor activation by immunoprecipitation, The time course of phosphorylation was very similar to that observed for carbachol (or UTP)-induced enzyme activation. Enzyme phosphorylation was prevented in the presence of okadaic acid. Calmodulin (CaM) kinase II inhibitors (i.e. KN-93 and KN-62) prevented phosphorylation of Zns(1,4,5)P-3 3-kinase. Identification of the phosphorylation site in transfected CHO cells indicated that the phosphorylated residue was Thr311. This residue of the human brain sequence lies in an active site peptide segment corresponding to a CaM kinase II-mediated phosphorylation consensus site, i.e. Arg-Ala-Val-Thr. The same residue in Ins(1,4,5)P-3 3-kinase A was also phosphorylated in vitro by CaM kinase II, Phosphorylation resulted in 8- to 10-fold enzyme activation and a 25-fold increase in sensitivity to the Ca2+:CaM complex. In this study, direct evidence is provided for a novel regulation mechanism for Ins(1,4,5)P-3 S-kinase (isoform A) in vitro and in intact cells.