TRANSCRIPTIONAL REGULATION BY THE CAM CASCADE

细胞内钙离子升高是细胞内最重要的信号传导之一， 细胞中的分子，尤其是神经组织中的分子。 其中一个重要 钙的作用是调节选定基因的转录， 从而改变细胞的表型。 一些研究 实验室，包括我们自己的实验室，已经证明， 钙调素依赖性蛋白激酶介导许多这些Ca 2 +- 依赖性转录事件。 特别是，我们专注于 钙调素激酶IV，可磷酸化几种反式激活 蛋白质如CREB和SRF。 在过去的两年里， 部分表征了由CaM-激酶级联组成的CaM-激酶级联， 可磷酸化和激活CaM-激酶IV激酶激酶， 钙调蛋白激酶I。 在目前的拨款申请中，我们将进一步 通过以下方式表征该CaM激酶级联的参与：1） 识别级联的额外上游组分（例如CaM-1）。 激酶激酶）或CaM-激酶激酶的锚定蛋白。 （二） 通过以下方法鉴定CaM-激酶IV的另外的反式激活蛋白： 检查NGFI-B基因的转录调节， 激酶级联 3)确定位置和生理相关性 CaM激酶级联和MAP激酶之间的串扰 级联。 这些研究将在各种培养细胞中进行， 特别是PC 12细胞，并将利用生物化学和分子生物学， 生物技术 这项研究的结果对 调节细胞凋亡和突触可塑性由于钙离子 依赖性基因转录。

Elevated intracellular calcium is one of the most important signaling molecules in cells, especially in neural tissues. One of the important actions of calcium is to regulate the transcription of selected genes, thereby altering the phenotype of the cell. Studies from a number of laboratories, including our own, have demonstrated that a family of calmodulin-dependent protein kinases mediate many of these Ca2+- dependent transcriptional events. In particular, we have focused on CaM-kinase IV which can phosphorylate several transactivating proteins such as CREB and SRF. In the past two years we have partially characterized a CaM-kinase cascade consisting of a CaM- kinase kinase which can phosphorylate and activate CaM-kinase IV and CaM-kinase I. In the current grant application we will further characterize the involvement of this CaM-kinase cascade by: 1) identifying additional upstream components of the cascade (e.g. CaM- kinase kinase kinase) or anchoring proteins for CaM-kinase kinase. 2) identifying additional transactivating proteins for CaM-kinase IV by examining transcriptional regulation of the NGFI-B gene by the CaM- kinase cascade. 3) determining the sites and physiological relevance of cross-talk between the CaM-kinase cascade and the MAP-kinase cascade. These studies will be performed in a variety of cultured cells, especially PC12 cells, and will utilize biochemical and molecular biological techniques. The results of this study have implications for modulating cellular apoptosis and synaptic plasticity due to Ca2+- dependent gene transcription.