Study of signal transduction via an SH2 which recognizes phosphotyrosine residues of proteins

通过识别蛋白质磷酸酪氨酸残基的 SH2 进行信号转导研究

基本信息

批准号：
07307003
负责人：
YAMAMURA Hirohei
金额：
$ 8.64万
依托单位：
KOBE UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1996
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07307003/
关键词：
Syk protein-tyrosine kinase Lyn CD45 DT-40 cell SHP-2 protein-tyrosine phosphatase SHPS-1 SHp-2 チロシンホスファターゼパキシリン SH-PTP2 CSk ZAP-70 Trk

项目摘要

SH2 (src homology region 2) is a region which specifically recognized the phosphotyrosine residues in various proteins and is believed to be an important structure in signal transduction. A non-receptor type protein-kinase Syk is expressed in almost all the hematopoietic cells. We tried to found out the importance of 2 SH2 of Syk in signal transduction. Both SH2 domains were required for BCR-mediated Syk and phospholipase C_<gamma>2 phosphorylation, inositol 1,4,5-triphosphate release and calcium mobilization. A possible explanation for this requirement was provided by findings that recruitment of Syk to tyrosine-phosphorylated immuno-globulin a and reqiures both Syk SH2 domains.Protein tyrosine phosphatase, such as SHP-1 AND SHP-2, that contain SH2 domains play important roles in growth factor and cytokine signal transduction pathways. A protein of -115 kD that interacts with SHP-1 and SHP-2 was purified from v-src-transformed rat fibroblasts and the corresponding cDNA was cloned (SHP … More S-1). It has four YXX (L/V/I) motifs, potential tyrosine phosphorylation and SH2-domain binding sites, in its cytoplasmic region. SHP-1 may be a potential substrate for SHP-2 and may function in both growth factor-and cell adhesion-induced cell signaling.Interaction of Fyn and Zap-70 in T cells was studied. Deletion of both the SH2 and SH3 domains of Fyn resulted in the decrease of the assciation with Zap-70. Consistently, Fyn-SH2 and SH3 fused to glutathione S-transferase were able to bind to Zap-70. Thus multiple sites of Fyn and Zap-70 are involved in the association. We propose that Fyn phosphorylates and activates Zap-70 and that both kinases cooperate in TCR signaling.Tyrosine phosphorylation of paxillin was induced by nerve growth factor and epidermal growth factor and KCI.Various evidence suggested that tyrosine phosphorylation of paxillin may be involved in calcium-dependent events in neuronal and neuroendocrine cells.We have succeeded in making a CD45-deficient DT-40 cells. Using this cell lines we have found that the dephosphorylation of tyrosine residues at both autophosphorylation and negative regulatory sites is mediated by CD45 in vivo and that dephosphorylation of C-terminal tyrosine is a prerequisite for participation of Lyn in B cell receptor signaling.We have been searching the family of Syk/Zap-70 in brain and other tissues. We found novel kinases in brain and liver cells. Now we are purifying these kinases and cloning the cDNAs of these kinases. Less

SH2（src同源区2）是特异性识别各种蛋白质中的磷酸酪氨酸残基的区域，被认为是信号转导中的重要结构。非受体型蛋白激酶Syk在几乎所有造血细胞中表达。试图找出 Syk 的 2 SH2 在信号转导中的重要性，两个 SH2 结构域都是 BCR 介导的 Syk 和磷脂酶 C_<gamma>2 磷酸化所必需的，肌醇 1,4,5-三磷酸释放和钙动员的发现为这一要求提供了可能的解释，即 Syk 募集到酪氨酸磷酸化免疫球蛋白 a 并需要两个 Syk SH2 结构域。蛋白质酪氨酸磷酸酶，例如 SHP-。 1 和 SHP-2 包含 SH2 结构域，在生长因子和细胞因子信号转导途径中发挥重要作用，是一种 -115 kD 的蛋白质。与 SHP-1 和 SHP-2 相互作用，从 v-src 转化的大鼠成纤维细胞中纯化，并克隆相应的 cDNA（SHP … 更多 S-1），它具有四个 YXX (L/V/I) 基序，潜在的酪氨酸磷酸化。 SHP-1 的细胞质区域中的 SH2 结构域结合位点可能是 SHP-2 的潜在底物，并且可能在生长因子诱导的细胞和细胞粘附诱导的细胞中发挥作用。研究了 Fyn 和 Zap-70 在 T 细胞中的相互作用，Fyn 的 SH2 和 SH3 结构域的缺失导致与 Zap-70 的结合减少。能够结合 Zap-70，因此 Fyn 和 Zap-70 的多个位点参与了这种结合。 Zap-70 和两种激酶在 TCR 信号传导中协同作用。桩蛋白的酪氨酸磷酸化是由神经生长因子、表皮生长因子和 KCI 诱导的。各种证据表明桩蛋白的酪氨酸磷酸化可能参与神经元和神经内分泌细胞的钙依赖性事件我们已经成功地制备了 CD45 缺陷型 DT-40 细胞，我们发现该细胞系的去磷酸化。自身磷酸化和负调控位点的酪氨酸残基在体内均由 CD45 介导，C 端酪氨酸去磷酸化是 Lyn 参与 B 细胞受体信号传导的先决条件。我们一直在脑中寻找 Syk/Zap-70 家族我们在脑和肝细胞中发现了新的激酶，现在我们正在纯化这些激酶并克隆这些激酶的 cDNA。