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Elucidation of Molecular Mechanism of Signal Transduction Mediated by Growth Factor-Receptor System

生长因子-受体系统介导的信号转导分子机制的阐明

基本信息

批准号：
05453210
负责人：
INAGAKI Fuyuhiko
金额：
$ 3.58万
依托单位：
Tokyo Metropolitan Institute of Medical Science
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05453210/
关键词：
NMR distance geometry solution structure erabutoxin b heregulin alpha IGF-II SH3 domain proline-rich peptide

项目摘要

We constructed a computer program system to determine the high reolution solution structure of proteins by NMR.The program were applied to determine the structure of heregulin, which is a ligand to ErbB4 receptor which is similar to EGF receptor but is important for regemeration of central nervous system and tumor fotmation. The structure is quite similar to EGF and we expect that heregulin also has similar binding surface to EGF.The patch on the putative receptor binding surface is quite different from that of EGF,supporting that these ligand bind exclusively to cognate receptors. We also determind the solution structure of IGF-II.IGF-II is similar to insulin and IGF-I.We found that the binding sites for insulin/IGF-I receptor and IGF-II receptor are located on the opposite surface of IGF-II.We extended our structural study to the protein interaction in the cytosolic state. SH2 and SH3 are structural module integrated in the signal transduction system. SH2 binds to the activated receptors by the binding to a phosphotyrosine residue in the receptor. Src-homology 3 (SH3) domains mediate signal transduction by binding to proline-rich motifs in target proteins involved in signal transduction system. We have determined the high-resolution structure of the SH3 domains of PLCgamma and Grb2. The three dimensional structure of SH3 domains are quite similar in spite of the low sequence homology (20%). But, owing to low affinity of proline-rich peptide to those SH3 domains, we could not determind the complex structures. Fortunately, VPPPVPPRRR peptide derived from Sos bound to Grb2 N-SH3 with high affinity and we have determined the high-resolution NMR structure of the complex. The NMR data show that the peptide adopts the conformation of a left-handed polyproline type II helix and interacts with three major sites on the SH3 domain. The orientation of the bound peptide is opposite to that of proline-rich peptides bound to the SH3 domains of Abl, Fyn and p85.

我们构建了一个用核磁共振测定蛋白质高分辨溶液结构的计算机程序系统，并将其用于测定ErbB4受体的结构。Hereglin是ErbB4受体的配体，与EGF受体相似，但对中枢神经系统的再生和肿瘤信息具有重要作用。其结构与EGF非常相似，我们预计Hereglin也具有与EGF相似的结合面。推测的受体结合面上的补丁与EGF的结合面有很大不同，支持这些配体仅与同源受体结合。我们还测定了IGF-II的溶液结构，IGF-II类似于胰岛素和IGF-I。我们发现胰岛素/IGF-I受体和IGF-II受体的结合部位位于IGF-II的相反表面。我们将结构研究扩展到胞液状态下的蛋白质相互作用。SH2和SH3是集成在信号转导系统中的结构模块。Sh2通过与受体中的磷酸酪氨酸残基结合而与激活的受体结合。SRC-Homology 3(SH3)结构域通过与参与信号转导系统的靶蛋白中富含脯氨酸的基序结合来介导信号转导。我们已经确定了PLCGamma和Grb2的SH3结构域的高分辨结构。SH3结构域的三维结构非常相似，尽管序列同源性很低(20%)。但是，由于富含Pro的多肽与SH3结构域的亲和力较低，我们无法确定其复杂的结构。幸运的是，从SOS衍生的VPPPVPPRRR多肽与Grb2 N-SH3高亲和力结合，我们确定了该配合物的高分辨核磁共振结构。核磁共振数据表明，该多肽采用左旋多聚脯氨酸II型螺旋构象，并与SH3结构域上的三个主要位点相互作用。结合的多肽与Ab1、Fyn和P85的SH3结构域结合的富含Pro的多肽方向相反。