The ubiquitin proteasome system in ER quality control

描述(申请人提供)：内质网合成的蛋白质的折叠和组装受到质量控制装置的密切监控，该装置将折叠缺陷的产物转移到胞浆中，由泛素-蛋白酶体系统通过一种称为内质网相关降解(ERAD)的过程进行降解。该项目的长期目标是阐明ERAD识别和摧毁其目标的机制。在之前的资助期间，我们成功地对哺乳动物ERAD系统进行了大规模的蛋白质组学分析，使我们能够创建第一个哺乳动物ERAD相互作用组的全面过程粒度图谱。我们利用这些数据来识别新的ERAD组分和蛋白质复合体，并提出了一个新的假说，即核心N-糖链的甘露糖修剪协调了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检验这一假设，完善ERAD相互作用网络，并发现新的ERAD成分，而不是基于真菌的正交学。为此，我们将利用新兴技术，如基因编辑、超高密度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.