Signal Transduction Mediated by Multifunctional Ca^<2+>/calmodulin-dependent Protein Kinases

多功能Ca^2/钙调蛋白依赖性蛋白激酶介导的信号转导

基本信息

批准号：
10102002
负责人：
FUJISAWA Hitoshi
金额：
$ 137.6万
依托单位：
Asahikawa Medical College
依托单位国家：
日本
项目类别：
Grant-in-Aid for Specially Promoted Research
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10102002/
关键词：
Calcium ion Calmodulin CaM-kinase cascade CaM-kinase II CaM-kinase IV CaM kinase kinase CaM-kinase phosphatase CaM-kinase phosphatase N Aキナーゼ CaMキナーゼI シグナル伝達蛋白質リン酸化酵素蛋白質脱リン酸化酵素

项目摘要

1. Regulation of CaM-kinase IICa^<2+>/calmodulin-dependent protein kinase (CaM-kinase) II is activated through autophosphorylation of Thr-286. We purified a new protein phosphatase (named CaM-kinase phosphatase), which dephosphorylates the phosphorylated Thr-286 restoring the activated CaM-kinase II to its original state, from rat brain and studied the properties of CaM-kinase phosphatase.The binding affinity for calmodulin of CaM-kinase II was studied using surface plasmon resonance. The dissociation rate constant of CaM-kinase II for calmodulin was decreased upon autophosphorylation of Thr-286 by approximately 10, 000-fold, suggesting that CaM-kinase II, once activated, can keep calmodulin even in the presence of many calmodulin-binding proteins. Thus, CaM-kinase II, once activated, may keep the highest activity in the cell until cytosolic Ca^<2+> is completely pumped out of the cell.2. Regulation of CaM-kinases IV and ICaM-kinases IV and I which have been activated upon phosphorylat … More ion of Thr-196 and Thr-177, respectively, by an upstream CaM-kinase kinase were deactivated by incubation with CaM-kinase phosphatase. CaM-kinase phosphatase specifically dephosphorylated phosphorylated Thr-286, Thr-196, and Thr-177 of CaM-kinases II, IV, and I, respectively. Thus, the activities of the three multifunctional CaM-kinases, such as CaM-kinases I, II, and IV, are all regulated by phosphorylation and dephosphorylation catalyzed by a specific protein kinase and phosphatase.3. Identification of CaM-kinase phosphatase NA protein (named CaM-kinase phosphatase N) showing a sequence homology to CaM-kinase phosphatase was found by a database search. CaM-kinase phosphatase N has a substrate specificity and other catalytic properties very similar to those of CaM-kinase phosphatase. However, CaM-kinase phosphatase is distributed in the cytosol but CaM-kinase phosphatase N is distributed in the cell nuclei.4. Possible model for CaM-kinase cascadeOn the basis of the results that tissue and subcellular distributions of CaM-kinases, CaM-kinase kinases, and CaM-kinase phosphatases were examined, a possible model for CaM-kinase cascade was proposed. Less

1。凸轮激酶IICA^<2+>/钙调蛋白依赖性蛋白激酶（CAM-激酶）II的调节通过THR-286的自磷酸化激活。我们纯化了一种新的蛋白质磷酸酶（称为Cam-激酶磷酸酶），该酶将磷酸化的THR-286降低，将活化的Cam-激酶II恢复到其原始状态，从大鼠脑和cam-激酶磷酸酶的特性。使用Cam-Kinase II的结合蛋白II使用Susticiod Plasson Resonance。 CAM-激酶II的分解速率常数在THR-286的自磷酸化中降低约10，000倍，这表明即使存在许多钙调蛋白结合蛋白质，也可以保持cam-激酶II，即使存在激活，也可以保持钙调氟辛。一旦激活，Cam-激酶II可能会保留细胞中最高的活性，直到胞质Ca^<2+>完全从细胞中抽出。2。 cam-激酶IV和ICAM-激酶IV和I的调节在磷酸lat上已激活……分别通过上游CAM-激酶与凸轮激酶孵育，分别通过上游CAM-激酶将更多的THR-196和THR-177离子取消。 Cam-磷酸酶分别是凸轮激酶II，IV和I分别脱磷酸化的THR-286，THR-196和THR-177。这就是由特定蛋白激酶和磷酸酶催化的磷酸化和去磷酸化催化的三种多功能CAM激酶的活性，例如凸轮I，II和IV。通过数据库搜索发现了与凸轮激酶磷酸酶的序列同源性的凸轮激酶磷酸酶Na蛋白（命名为CAM-激酶磷酸酶N）。 CAM-激酶磷酸酶N具有与CAM-激酶磷酸酶非常相似的底物特异性和其他催化特性。然而，凸轮激酶磷酸酶分布在细胞质中，但凸轮激酶磷酸酶N分布在细胞核中。4。凸轮激酶Cascadeon的可能模型是检查了凸轮激酶，凸轮激酶和凸轮激酶磷酸酶的组织和亚细胞分布的基础，提出了凸轮激酶级联反应的可能模型。较少的