Analysis of a novel signaling system, the Rap2-MAP4K signaling complex

新型信号系统 Rap2-MAP4K 信号复合物的分析

基本信息

批准号：
18590303
负责人：
KARIYA Ken-ichi
金额：
$ 2.27万
依托单位：
University of the Ryukyus
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18590303/
关键词：
signal transduction Rap2 MAP4K MAPKKKキナーゼシグナル複合体 NIK HGK TNIK MINK

项目摘要

We have previously shown that a Ras family small GTP-binding protein Rap2 interacts specifically with MAPKKK kinases (MAP4Ks) that activate the stress-activated MAPK, c-Jun N-terminal kinase (JNK). We believe that Rap2 and MAP4Ks interact with upstream molecules for regulation of Rap2 in response to upstream signals and downstream molecules for transmission of MAP4K signals and that they form a signaling complex, termed Rap2-MAP4K signaling complex. In the present study, we have examined the regulatory mechanisms and cellular functions of this complex, using an epidermal cell line as a model.1. Components and regulatory mechanisms of the signaling complexIn order to identify major components of the signaling complex, we searched for molecules that interact with MAP4Ks. We have identified a protein of approximately 200 kDa (p200) containing the central repeat structure, cystein-rich domain and a C-terminal PDZ-binding motif. This protein appeared to be a mammalian homolog of a Drosophila scaffold protein. We also believe that the complex contains a dimer or oligomer of MAP4Ks.2. Functional analysis of the signaling complexIn fibroblastic cells, Rap2-MAP4K complex regulates cell-substratum adhesion. On the other hand, in epithelial cells, the complex appeared to regulate cell-cell adhesion. We have used a retrovirus system to establish cell lines in that expression of tagged MAP4Ks can be regulated by tetracycline (Tet-Off). Over-expression of MAP4Ks, but not kinase-deficient mutants, negatively regulated cell-cell adhesion.

我们以前已经表明，RAS家族小的GTP结合蛋白RAP2与MAPKKK激酶（MAP4K）专门相互作用，该激酶激活了应力激活的MAPK，C-JUN N末端激酶（JNK）。我们认为，RAP2和MAP4K与上游分子相互作用，以响应上游信号和下游分子以传输MAP4K信号，并形成信号复合物，称为RAP2-MAP4K信号复合物。在本研究中，我们使用表皮细胞系作为模型研究了该复合物的调节机制和细胞功能。1。信号传导复合素顺序的组件和调节机制以识别信号传导复合物的主要成分，我们搜索了与MAP4K相互作用的分子。我们已经确定了一个大约200 kDa（P200）的蛋白质，其中包含中央重复结构，富含Cystein的结构域和C末端PDZ结合基序。该蛋白似乎是果蝇支架蛋白的哺乳动物同源物。我们还认为该复合物包含MAP4Ks.2的二聚体或低聚物。信号传导复杂素成纤维细胞的功能分析，RAP2-MAP4K复合物调节细胞肌间粘附。另一方面，在上皮细胞中，该复合物似乎调节细胞 - 细胞粘附。我们已经使用逆转录病毒系统来建立细胞系在标记的MAP4K的表达中，可以通过四环素（TET-OFF）调节。 MAP4K的过表达，而不是激酶缺陷的突变体，负调控细胞 - 细胞粘附。