Identification and Functional Analysis of Protein Kinase C-Related Gene

蛋白激酶C相关基因的鉴定及功能分析

基本信息

批准号：
03454164
负责人：
OHNO Shigeo
金额：
$ 4.03万
依托单位：
YOKOHAMA CITY UNIVERSITY SCHOOL OF MEDICINE
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

We have isolated cDNA clones encoding a new PKC family member PKC lambda. PKC lambda shows closest amino acid sequence identity with PKCzata(70% in total) and is structurally classified into the third sub-family of PKC. Expression of cDNAs for PKCzata and lambda in COS cells revealed the similarity in their biochemical properties in that both on them do not possess phorbol ester binding activities and that their kinase activities are not dependent on Ca, diacylglycerols, and phorbol esters. These structural and biochemical properties of PKCzata and lambda indicates that they are not the cellular receptor to diacylglycerols nor phorbol esters. Thus this subfamily is termed as aPKC (atypical PKC) subfamily.In order to examine the functional differences of aPKC (zata, lambda) from conventional cPKC (alpha,beta,gamma) and from nPKC (delta,epsilon,eta,rheta), the effect of the overexpression of each of the members on the transcriptional activation of several cis-acting elements were examined. Overexpression of aPKC resulted in an enhancement of the transcriptional activation of TPA-response element (TRE) in response to serum but not TPA. Overexpression of cPKC or nPKC resulted in an enhanced transcriptional activation of a TPA-response element in response to TPA.The results clearly indicate that aPKC is a novel family of signal transducing protein kinases which transmit a signal to TRE. Furthermore, the mode of the activation of aPKC differs from cPKC and nPKC. Further experiments to identify the serum factor which activates aPKC revealed that aPKC is activated in cells in response to tyrosine-kinase receptor activation implying the presence of a novel signaling pathway in cells from Tyr-kinase receptor to aPKC activation.

我们已经孤立的cDNA克隆编码了新的PKC家庭成员PKC Lambda。 PKC lambda与PKCZATA显示最接近的氨基酸序列同一性（总计70％），并在结构上分类为PKC的第三个亚家族。 COS细胞中PKCZATA和LAMBDA的cDNA表达揭示了其生化特性的相似性，因为它们上的两者都不具有佛比尔酯的结合活性，并且它们的激酶活性不依赖于Ca，二酰基甘油和凤凰酯。 PKCZATA和LAMBDA的这些结构和生化特性表明，它们不是二酰基甘油或佛罗宝酯的细胞受体。因此，该亚家族被称为APKC（非典型PKC）亚家族。为了检查传统CPKC（Zata，lambda）的功能差异（Zata，lambda）的功能差异（Alpha，beta，beta，Gamma）以及NPKC（Delta，Epsilon，Eta，rheta）的效应的几种效应，该效应的效应是检查了元素。 APKC的过表达导致TPA反应元件（TRE）的转录激活增强，以响应血清而不是TPA。 CPKC或NPKC的过表达导致对TPA的TPA反应元件的转录激活增强。结果清楚地表明，APKC是一个新型的信号转导蛋白激酶的家族，将信号传递给TRE的蛋白质激酶。此外，APKC激活的模式与CPKC和NPKC不同。进一步的实验以鉴定激活APKC的血清因子表明，在响应酪氨酸激酶受体激活的细胞中激活APKC，这意味着从Tyr-激酶受体到APKC激活的细胞中存在新的信号传导途径。