REGULATION AND SUBSTRATE SPECIFICITY OF SHP1 AND SHP2

SHP1 和 SHP2 的调节和底物特异性

• 批准号: 6510886
• 负责人: GUANGWEN WAYNE ZHOU
• 金额: $ 30.53万
• 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 2004-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6510886
• 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(改编自调查人员摘要)：SHPS属于一个家庭 含有两个串联的胞浆蛋白酪氨酸磷酸酶(PTPs) N-末端的Sh2-结构域，后面跟着一个催化结构域和一个 C-末端尾巴。Sh2结构域靶向SHPS的磷酸化酪氨酸残基 生长因子受体及其抑制受体的ITIM基序 淋巴细胞。SHPS在体外表现出很低的比活性 其他PTP。这在一定程度上是由于它们的监管机构的自动抑制 域名。酪氨酸磷酸化多肽与其SH2结构域的结合 ITIM基序可以提高PTPase的活性。根本问题 在这份针对自置居所计划的建议中，如何在 SHPS的N末端(结合ITIM基序)激活蛋白质酪氨酸 磷酸酶？按顺序提出了生化和结晶学方法。 了解住房公积金计划的调控机制。这篇文章中提到的另一个问题 提出SHPS底物专一性的结构基础是什么？ 该提案将审查小水电的特殊性，通过详细的动力学 针对各种潜在底物进行分析，包括ITAM、CD22、CD72 或CTLA4。与这些研究相辅相成的是 不同磷酸酪氨酸肽的SHP-1和SHP-2的催化结构域 结合，以鉴定SHP-1和SHP-2中的底物结合口袋。 还提出了一种用于识别理想衬底的筛子 可与突变的酪氨酸酶催化结构域结合的磷酸化酪氨酸肽 SHP-1和SHP-2，使用定向肽库技术。长期的 这项提案的目标是了解微调监管职能 SHP-1和SHP-2对淋巴细胞信号转导的影响。