ANALYSIS OF EUKARYOTIC PROTEIN KINASES AND PHOSPHO-REGULATORY SYSTEMS

真核蛋白激酶和磷酸调节系统的分析

• 批准号: 8361636
• 负责人: FRANK SICHERI
• 金额: $ 4.94万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8361636
• 关键词: Binding; Cleaved cell; Complex; Endoplasmic Reticulum; Enzyme Kinetics; Flavonols; Funding; Grant; Ligand Binding; Ligands; Messenger RNA; National Center for Research Resources; Nucleotides; Phosphotransferases; Principal Investigator; Protein Kinase; Proteins; Quercetin; Research; Research Infrastructure; Resources; Ribonucleases; Signal Transduction; Site; Source; Stress; Structure; System; United States National Institutes of Health; Yeasts; analytical ultracentrifugation; cost; crosslink; dimer; drug development; endonuclease; endoplasmic reticulum stress; nuclease; response; structural biology

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Signaling in the most conserved branch of the endoplasmic reticulum (ER) unfolded protein response (UPR) is initiated by sequence-specific cleavage of the HAC1/XBP1 mRNA by the ER stress-induced kinase-endonuclease IRE1. We have discovered that the flavonol quercetin activates yeast IRE1's RNase and potentiates activation by ADP, a natural activating ligand that engages the IRE1 nucleotide binding cleft. Enzyme kinetics and the structure of a cocrystal of IRE1 complexed with ADP and quercetin reveal engagement by quercetin of an unanticipated ligand-binding pocket at the dimer interface of IRE1's kinase extension nuclease (KEN) domain. Analytical ultracentrifugation and crosslinking studies support the preeminence of enhanced dimer formation in quercetin's mechanism of action. These findings hint at the existence of endogenous cytoplasmic ligands that may function alongside stress signals from the ER lumen to modulate IRE1 activity and at the potential for the development of drugs that modify UPR signaling from this unanticipated site.

这个子项目是许多利用资源的研究子项目之一 由NIH/NCRR资助的中心拨款提供。子项目的主要支持 而子项目的主要调查员可能是由其他来源提供的， 包括其它NIH来源。 列出的子项目总成本可能 代表子项目使用的中心基础设施的估计数量， 而不是由NCRR赠款提供给子项目或子项目工作人员的直接资金。 内质网（ER）未折叠蛋白反应（UPR）的最保守分支中的信号传导通过ER应激诱导的激酶内切核酸酶IRE 1对HAC 1/XBP 1 mRNA的序列特异性切割而启动。我们已经发现黄酮醇槲皮素激活酵母IRE 1的RNA酶并增强ADP的激活，ADP是一种天然的激活配体，与IRE 1核苷酸结合裂缝接合。酶动力学和结构的共晶体的IRE 1与ADP和槲皮素复合揭示了一个意想不到的配体结合口袋在IRE 1的激酶延伸核酸酶（KEN）结构域的二聚体界面的槲皮素订婚。 分析超离心和交联研究支持槲皮素的作用机制中增强二聚体形成的优势。这些发现暗示了内源性胞质配体的存在，其可能与来自ER腔的应激信号一起发挥作用以调节IRE 1活性，并且暗示了开发修饰来自该意外位点的UPR信号传导的药物的潜力。