REGULATION OF IRE1A SIGNALING BY THE SEL1L-HRD1 ERAD COMPLEX

SEL1L-HRD1 ERAD 复合物对 IRE1A 信号传导的调节

• 批准号: 9180708
• 负责人: Ling Qi
• 金额: $ 29.84万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-08-01 至 2018-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9180708
• 关键词: Address; Adipose tissue; Attenuated; Biochemical Genetics; Biological; Biology; Calnexin; Cell Death; Cell Survival; Cell model; Cells; Cellular biology; Cessation of life; Colon; Complex; Data; Endoplasmic Reticulum; Ensure; Event; GRP78 gene; Generations; Goals; Health; Homeostasis; Human; Integral Membrane Protein; Knockout Mice; Lectin; Life; Light; Link; Maintenance; Mannose; Mediating; Membrane; Metabolic Diseases; Molecular; Molecular Chaperones; Myosin Type II; Nerve Degeneration; Pancreas; Pathway interactions; Pharmacology; Physiological; Play; Polysaccharides; Post-Transcriptional Regulation; Process; Proteins; Quality Control; Regulation; Reporting; Role; Signal Transduction; Spleen; System; Testing; The Sun; Therapeutic; Tissues; Transcriptional Regulation; Ubiquitination; Yeasts; base; cell type; cofactor; human disease; insight; interest; macrophage; misfolded protein; mouse model; non-muscle myosin; novel; public health relevance; response; sensor; tool; ubiquitin ligase

DESCRIPTION (provided by applicant): Our long-term goal is to delineate the molecular mechanisms underlying the maintenance of endoplasmic reticulum (ER) homeostasis by two key quality-control systems in the cell, ER-associated degradation (ERAD) and unfolded protein response (UPR). Recently, we have identified a novel regulator of IRE1α, the most conserved sensor of the UPR (He et al. Dev Cell 2012), and reported the generation and characterization of inducible Sel1L knockout (Sel1LIKO) mouse and cell models (Sun et al. PNAS 2014), a cofactor of the ubiquitin ligase Hrd1 in mammalian ERAD. In the preliminary data of this application, we discovered a unique crosstalk between UPR and ERAD, namely the regulation of IRE1α stability by the Sel1L-Hrd1 ERAD complex. Here we showed that loss of Sel1L-Hrd1 ERAD function leads to a dramatic accumulation of IRE1α protein in various tissues and cell types including pancreas, colon, spleen, adipose tissue, MEFs, macrophages and etc. IRE1α accumulation in the absence of Sel1L is independent of transcriptional regulation, pointing to a post-transcriptional control. Indeed, IRE1α interacts with Sel1L and is significantly stabilized in the absence of Sel1L or Hrd1. Thus, these data point to IRE1α as a misfolding- prone Sel1L-Hrd1 ERAD substrate. Here we propose to test the hypotheses that IRE1α is an ERAD substrate and that the Sel1L-Hrd1 ERAD complex negatively regulates the amplitude of IRE1α signaling by mediating its degradation. Taking advantage of systems and tools that we have generated for both Sel1L ERAD and IRE1α, we will accomplish the following Aims: (1) Determine the biological significance of IRE1α ERAD on IRE1α signaling and cell survival; (2) Determine how misfolded IRE1α protein is recognized and delivered to the Sel1L-Hrd1 ERAD complex; and (3) Elucidate how misfolded IRE1α protein is degraded by the Sel1L-Hrd1 ERAD complex. Successful completion of this study may not only provide key insights into IRE1α and ERAD biology, but also uncover a novel regulatory mechanism for IRE1α signaling. This study will provide an unprecedented opportunity to investigate the complicated mechanism of ERAD using an endogenous substrate with great physiological significance, thus exerting a powerful influence on our views of physiological ERAD and UPR biology.

描述（通过应用程序提供）：我们的长期目标是描述维持内质网（ER）稳态的分子机制，通过细胞中的两个关键质量控制系统，与ER相关的降解（ERAD）和不折叠的蛋白质反应（UPR）。最近，我们确定了IRE1α的新型调节剂，IRE1α是UPR的最保守的传感器（He。DevCell 2012），并报道了诱导型SEL1L敲除（SEL1LIKO）小鼠和细胞模型的产生和表征（Sun等人PNAS 2014），ubiquitin ligase ligase ligase ligase hrd1 in mammalian in Mammalian erad。在此应用程序的初步数据中，我们发现了UPR和ERAD之间的独特串扰，即SEL1L-HRD1 ERAD复合物对IRE1α稳定性调节。在这里，我们表明SEL1L-HRD1 ERAD功能的损失导致在各种时机和细胞类型中的IRE1α蛋白的急剧积累，包括胰腺，结肠，sleen，sleen，脂肪组织，MEFS，巨噬细胞，巨噬细胞和巨噬细胞等。SEL1L的缺乏，sel1l与转录调节无关，与POSTINCTIONCT-POSTINCTIONS-POSTINCTIONS-POSTINCTION。实际上，IRE1α与SEL1L相互作用，并在 缺乏SEL1L或HRD1。这是这些数据表明IRE1α是一个易折叠的 - 容易发生的SEL1L-HRD1 ERAD底物。在这里，我们建议测试IRE1α是ERAD底物的假设，SEL1L-HRD1 ERAD复合物通过介导其降解来负调节IRE1α信号传导的放大器。利用我们为SEL1L ERAD和IRE1α生成的系统和工具，我们将实现以下目的：（1）确定IRE1αERAD在IRE1α信号传导和细胞存活下的生物学性； （2）确定如何识别后的IRE1α蛋白并将其传递到SEL1L-HRD1 ERAD复合物中； （3）SEL1L-HRD1 ERAD复合物阐明了如何折叠的IRE1α蛋白是如何降解的。这项研究的成功完成不仅可以为IRE1α和ERAD生物学提供关键的见解，而且还可以发现一种新型的IRE1α信号调节机制。这项研究将提供一个前所未有的机会，使用具有巨大物理意义的内源性底物研究ERAD的复杂机制，从而对我们对物理ERAD和UPR生物学的看法产生了强大的影响。