The role of UFMylation in ribosome quality control at the ER

UFMylation 在 ER 核糖体质量控制中的作用

• 批准号: 10561470
• 负责人: RON R KOPITO
• 金额: $ 58.26万
• 依托单位: STANFORD UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2026-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10561470
• 关键词: ATP phosphohydrolase; Binding; Biochemical; Biogenesis; Cells; Collaborations; Cytoplasm; Cytosol; Data; Defect; Disease; Dislocations; Dissection; Endoplasmic Reticulum; Endoplasmic Reticulum Degradation Pathway; Ensure; Foundations; Genome; Goals; Human; Impairment; In Vitro; Knowledge; Label; Lysine; Membrane; Membrane Proteins; Modification; Molecular; Monitor; Organelles; Outcome; Pathway interactions; Peptides; Play; Process; Protein Biosynthesis; Proteins; Publishing; Quality Control; Reader; Recycling; Research; Ribosomal Proteins; Ribosomes; Role; Route; Structure; System; Testing; Time; Transfer RNA; Ubiquitin; Ubiquitin Like Proteins; Work; experimental study; genetic information; human disease; innovative technologies; insight; multicatalytic endopeptidase complex; proteostasis; proteotoxicity; recruit; response; seal; secretory protein; segregation; time use; ubiquitin-protein ligase

Project Summary Ribosomes are macromolecular machines that decode the genome. Quality control mechanisms that ensure the fidelity of this process are thus of paramount importance cellular and organismal viability. Ribosomes move at variable rates, slowing down or even pausing to facilitate organelle targeting, domain folding and co-translational assembly, but prolonged stalls are deleterious to cells because they can deplete functional ribosomes and produce highly toxic truncated nascent chains. Stalls that occur on endoplasmic reticulum (ER) ribosomes are even more damaging because they additionally obstruct the translocons through which all secreted and membrane proteins must transit en route to the secretory pathway. Ribosome quality control (RQC) is a conserved and essential process that rescues stalled 60S subunits by extracting the obstructing nascent chain and degrading it by the UPS. Despite immense progress in the past decade in defining RQC for cytosolic ribosome, the how RQC operates for ER-stalled ribosomes is almost completely uninvestigated. Recently my lab discovered that UFMylation – the process by which UFM1, a small ubiquitin-like protein is conjugated to ribosomes — plays a central and essential role specifically in adapting RQC to proteins synthesized at the ER. The three specific aims described in this proposal seek to build on the foundation provided by our extensive preliminary data to define the mechanism by which nascent chains that obstruct ribosomes that stall on ER translocons are extracted and degraded. In aim 1 we will conduct a systematic dissection of the RQC machinery to define the role of known RQC required to resolve stalled ribosomes at the ER. In aim 2 we will define the interplay between ribosome UFMylation and RQC and dentify the readers of UFMylated ribosomes at the ER. In aim 3 we will determine the structure of UFMyulated ribosomes and the E3 ligase that conjugates UFM1 to the ribosome.

项目摘要 核糖体是解码基因组的大分子机器。质量控制 因此，确保这一过程的保真度的机制是至关重要的 和有机体的生存能力。核糖体以可变的速率移动，减慢甚至暂停， 促进细胞器靶向，结构域折叠和共翻译组装，但延长停滞 对细胞是有害的，因为它们可以耗尽功能性核糖体并产生高毒性的 截短的新生链。在内质网（ER）核糖体上发生的停滞是均匀的。 更有害，因为它们额外地阻碍了所有分泌的translocons 并且膜蛋白必须在途中转运到分泌途径。核糖体质量 控制（RQC）是一个保守和必要的过程，通过以下方式拯救停滞的60 S亚基： 提取阻塞的新生链并通过UPS降解它。尽管巨大 在过去的十年中，在定义细胞溶质核糖体的RQC方面取得了进展，RQC如何运作， ER停滞的核糖体几乎完全未被研究。最近我的实验室发现， UFM化-UFM 1（一种小的泛素样蛋白）与 核糖体-在使RQC适应蛋白质方面起着核心和重要的作用 在急诊室合成的本建议中所述的三个具体目标旨在建立在 我们广泛的初步数据提供的基础，以确定机制， 提取阻碍滞留在ER转座子上的核糖体的新生链， 退化了在目标1中，我们将对RQC机制进行系统的剖析， 已知的RQC的作用需要解决停滞的核糖体在ER。在目标2中，我们将定义 核糖体UFMylation和RQC之间的相互作用，并确定UFMylated的读者 核糖体在ER。在目标3中，我们将确定UF-Myulated核糖体的结构， 将UFM 1结合到核糖体的E3连接酶。