REGULATION AND SUBSTRATE SPECIFICITY OF SHP1 AND SHP2

SHP1 和 SHP2 的调节和底物特异性

• 批准号: 2897531
• 负责人: GUANGWEN WAYNE ZHOU
• 金额: $ 31.38万
• 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/2897531
• 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）：SHP属于 胞质蛋白酪氨酸磷酸酶（PTPs），含有两个串联的 在N-末端的SH 2-结构域，随后是单个催化结构域和一个催化结构域。 C末端尾部SH 2结构域将SHP靶向至 生长因子受体和ITIM基序的抑制性受体， 淋巴细胞SHP在体外显示出非常低的比活性， 其他PTPs这部分是由于它们的调节性自我抑制。 域.其SH 2结构域与酪氨酸磷酸化肽的结合， ITIM基序可以增加PTB活性。它的实质就 本建议书中针对SHP提出的是， SHP的N-末端（结合ITIM基序）激活蛋白酪氨酸 磷酸酶？生物化学和晶体学方法被提出， 了解SHP的调节机制。另一个问题是， SHP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点， 分析，针对各种潜在的底物，包括ITAM、CD 22、CD 72 或CTLA 4。补充这些研究将是晶体结构的 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基板的屏幕， 磷酸酪氨酸肽，其可以结合至突变的催化结构域， SHP-1和SHP-2，使用定向肽库技术。长期 本建议的目的是了解微调监管职能， SHP-1和SHP-2对淋巴细胞信号传导的影响。