Eukaryotic Ribosome Assembly

真核核糖体组装

• 批准号: 10474590
• 负责人: Arlen W JOHNSON
• 金额: $ 57.03万
• 依托单位: UNIVERSITY OF TEXAS AT AUSTIN
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-14 至 2023-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10474590
• 关键词: Acute T Cell Leukemia; Cells; Complex; Defect; Ensure; Eukaryota; Eukaryotic Cell; Event; Genetic Transcription; Guanosine Triphosphate Phosphohydrolases; Human; Lead; Life; Ligands; Messenger RNA; Molecular; Molecular Machines; Pathway interactions; Peptidyltransferase; Planet Earth; Production; Proteins; Quality Control; RNA; RNA Helicase; Research Personnel; Ribosomal Biogenesis Pathway; Ribosomal Proteins; Ribosomes; Role; Shwachman-Diamond syndrome; Structure; Time; Translational Research; Translations; U3 small nucleolar RNA; genetic information; human disease; interest; particle; polypeptide; scaffold

PI: Arlen W Johnson Summary Ribosomes are responsible for the rapid and accurate production of all proteins in cells in all forms of life on earth. The ability of these molecular machines to carry out faithful translation depends on their complex structure that allows dynamic interaction with ligands. The mature ribosome in eukaryotic cells is composed of two parts, the large 60S subunit that carries out polypeptide synthesis and the small 40S subunit that decodes mRNA. The assembly of a eukaryotic ribosome involves over 200 accessory assembly factors, whose function, in many cases, is still unknown. Considering the complexity of ribosome structure and function and its critical role in decoding our genetic information, ensuring their correct assembly would seem a necessary but daunting task for cells. Lately, considerable interest has been focused on mechanisms of quality control in the ribosome biogenesis pathway. This proposal focuses on two distinct topics within ribosome assembly; (1) completion of the peptidyl transferase center of the 60S subunit and the mechanisms for assessing its functional integrity and (2) the transition from the early 90S pre-ribosomal precursor to the pre-40S precursor. This proposal is directed at understanding the quality control mechanisms that assess the functional and structural integrity of the peptidyl transferase center of the subunit, upon insertion of ribosomal protein Rpl10. This proposal builds on our recent determination of the atomic structure of a preribosome and release of two factors, Tif6 and Nmd3. The release of Nmd3 and Tif6 is dependent on the two GTPases Efl1 and Lsg1 and constitutes the primary quality control check point in during 60S maturation. In humans, defects in the quality control step lead to T-cell acute lymphoblastic leukemia and Shwachman-Diamond syndrome. Assembly of the small ribosomal subunit involves stepwise cotranscriptional assembly of the 90S particle, a large protein-RNA complex, scaffolded on U3-snoRNA. However, the presence of U3 is mutually incompatible with the final folded structure of small subunit RNA and must be removed once transcription of the RNA is complete and the 90S particle has fully assembled. The transition from the 90S to pre-40S is poorly understood. We propose that the displacement of U3 by the RNA helicase Dhr1 is a primary event that drives the transition of the 90S into the pre-40S particle. We will determine how the activity of Dhr1 is regulated to ensure the timely release of U3.

PI：Arlen W Johnson 概括 核糖体负责所有蛋白质的快速生产 在地球上各种形式的生命中。这些分子机执行的能力 忠实的翻译取决于它们的复杂结构，该结构允许动态互动 与配体。真核细胞中成熟的核糖体由两个部分组成， 进行多肽合成和小的40s亚基的大型60s亚基 解码mRNA。真核核糖体的组装涉及200多个附件 组装因子，其功能在许多情况下仍然是未知的。考虑到 核糖体结构和功能的复杂性及其在解码我们的遗传方面的关键作用 信息，确保其正确的组装似乎是一项必要但艰巨的任务 用于细胞。最近，人们对质量机制的关注很大 核糖体生物发生途径中的控制。该提案重点介绍了两个不同的主题 在核糖体组装中； （1）完成60s的肽基转移酶中心 亚基和评估其功能完整性的机制和（2）过渡 从90年代初期的前纹状体前体到40年代前的前体。 该建议旨在了解质量控制机制 评估肽基转移酶中心的功能和结构完整性 亚基插入核糖体蛋白RPL10。该提议建立在我们最近的 确定原子体的原子结构和两个因素的释放，tif6 和NMD3。 NMD3和TIF6的释放取决于两个GTPases EFL1和 LSG1构成60年代成熟期间的主要质量控制检查点。在 人类，质量控制步骤中的缺陷导致T细胞急性淋巴细胞白血病 和Shwachman-Diamond综合征。 小核糖体亚基的组装涉及逐步共转录 90年代粒子的组装，这是一种大蛋白RNA复合物，在U3-Snorna上支架。 但是，U3的存在与最终折叠结构相互兼容 小亚基RNA，一旦RNA的转录完成，就必须去除 90年代的粒子已完全组装。从90年代到40年代以前的过渡很差 理解。我们建议RNA解旋酶DHR1的U3位移是一个 将90年代过渡到40年代以前的粒子的主要事件。我们将 确定如何调节DHR1的活性，以确保及时释放U3。