The ubiquitin proteasome system in ER quality control

描述（由申请人提供）：内质网中合成的蛋白质的折叠和组装由质量控制装置密切监测，该质量控制装置将折叠缺陷产物转移到胞质溶胶中，通过称为内质网相关降解（ERAD）的过程由泛素-蛋白酶体系统降解。该项目的长期目标是阐明ERAD识别和摧毁其目标的机制。在上一个资助期，我们成功地实施了哺乳动物ERAD系统的大规模蛋白质组学分析，使我们能够创建哺乳动物ERAD相互作用组的第一个全面的过程粒度图。我们使用这些数据来识别新的ERAD组分和蛋白质复合物，并提出一种新的假设，其中核心N-聚糖的甘露糖修剪协调折叠缺陷蛋白质的有序识别和递送。本申请中提出的研究试图测试该假设，以细化ERAD相互作用网络并发现不基于真菌的直系同源的新ERAD组分。为此，我们将利用新兴技术，如基因编辑，微密度shRNA和遗传相互作用图谱。

DESCRIPTION (provided by applicant): Folding and assembly of proteins synthesized in the endoplasmic reticulum is closely monitored by a quality control apparatus that diverts folding-defective products to the cytosol to be degraded by the ubiquitin-proteasome system by a process known as endoplasmic reticulum-associated degradation (ERAD). The long-term goal of this project is to elucidate the mechanisms by which ERAD recognizes and destroys its targets. In the previous funding period we successfully implemented a large scale proteomic analysis of the mammalian ERAD system that allowed us to create the first comprehensive course-grained map of the mammalian ERAD interactome in mammals. We used these data to identify new ERAD components and protein complexes and to propose a novel hypothesis in which mannose trimming of core N-glycans orchestrates the ordered recognition and delivery of folding defective proteins. The studies proposed in the present application seek to test this hypothesis, to refine the ERAD interaction network and discover new ERAD components not based on orthology to fungi. To this end we will exploit emerging technologies such as gene editing, ultrahigh density shRNA and genetic interaction mapping.