REGULATION AND SUBSTRATE SPECIFICITY OF SHP1 AND SHP2

SHP1 和 SHP2 的调节和底物特异性

• 批准号: 6606965
• 负责人: GUANGWEN WAYNE ZHOU
• 金额: $ 0.8万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-07-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6606965
• 关键词: CD22 molecule; CD28 molecule; X ray crystallography; chemical binding; chemical kinetics; enzyme activity; enzyme structure; enzyme substrate; peptide library; phosphoprotein phosphatase

DESCRIPTION (Adapted from Investigator's Abstract): SHPs belong to a family of cytosolic protein tyrosine phosphatases (PTPs) that contain two tandem SH2-domains at the N-terminus followed by a single catalytic domain and a C-terminal tail. SH2 domains target SHPs to phosphorylated tyrosine residues of growth factor receptors and the ITIM motifs of the inhibitory receptors in lymphocytes. SHPs display a very low specific activity in vitro compared to other PTPs. This is partly due to the auto-inhibition by their regulatory domains. Binding of its SH2 domains to tyrosine-phosphorylated peptides with the ITIM motif can increase the PTPase activity. The essential question addressed in this proposal for SHPs is how does the modification at the N-terminus of SHPs (binding the ITIM motif) activate the protein tyrosine phosphatase? Biochemical and crystallographic approaches are proposed in order understand the regulatory mechanism of SHPs. Another question addressed in this proposal is what is the structural basis for the substrate specificity of SHPs? The proposal will examine the SHP specificities, through detailed kinetic analyses, against a variety of potential substrates including ITAMs, CD22, CD72 or CTLA4. Complementing these studies will be the crystal structures of the catalytic domain of SHP-1 and SHP-2, with different phosphotyrosine peptides bound, in order to identify the substrate binding pockets in SHP-1 and SHP-2. Also proposed is a screen for identifying ideal substrates using phosphotyrosine peptides that can be bound to the mutated catalytic domain of SHP-1 and SHP-2, using the oriented peptide library technique. The long-term goal of this proposal is to understand the fine-tuning regulatory functions of SHP-1 and SHP-2 on lymphocyte signaling.

描述（改编自研究者摘要）：小水电属于以下家族： 胞质蛋白酪氨酸磷酸酶 (PTP) 含有两个串联的 N 末端的 SH2 结构域，后面跟着一个催化结构域和一个 C末端尾部。 SH2 结构域将 SHP 靶向磷酸化的酪氨酸残基 生长因子受体和抑制性受体的 ITIM 基序 淋巴细胞。与相比，SHP 在体外表现出非常低的比活性 其他 PTP。这部分是由于监管机构的自动抑制 域。其 SH2 结构域与酪氨酸磷酸化肽的结合 ITIM基序可以增加PTPase活性。基本问题 该小水电提案中讨论的问题是如何修改 SHP 的 N 末端（结合 ITIM 基序）激活蛋白质酪氨酸 磷酸酶？提出了生物化学和晶体学方法 了解小水电的监管机制。本文讨论的另一个问题 建议是小水电底物特异性的结构基础是什么？ 该提案将通过详细的动力学研究小水电的特殊性 针对各种潜在底物（包括 ITAM、CD22、CD72）进行分析 或CTLA4。对这些研究的补充将是晶体结构 SHP-1 和 SHP-2 的催化结构域，具有不同的磷酸酪氨酸肽 结合，以确定 SHP-1 和 SHP-2 中的底物结合袋。 还提出了一种用于识别理想基材的屏幕 磷酸酪氨酸肽可与突变的催化结构域结合 SHP-1和SHP-2，采用定向肽库技术。长期来看 该提案的目标是了解监管职能的微调 SHP-1 和 SHP-2 对淋巴细胞信号传导的影响。