Structural and functional studies of mRNA processing, stability and quality control

mRNA 加工、稳定性和质量控制的结构和功能研究

• 批准号: 9915949
• 负责人: LIANG TONG
• 金额: $ 74.59万
• 依托单位: COLUMBIA UNIV NEW YORK MORNINGSIDE
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2021-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9915949
• 关键词: Biochemical; Cell Nucleus; Cells; Cleavage And Polyadenylation Specificity Factor; Cleavage Stimulation Factor; Complex; Cytoplasm; Defect; Event; Fibrinogen; Genetic Transcription; Histones; Knowledge; Link; Mammals; Messenger RNA; Molecular; Molecular Mechanisms of Action; Polyadenylation; Polynucleotide Adenylyltransferase; Protein Family; Proteins; Prothrombin; Quality Control; RNA; RNA Polymerase II; RNA Splicing; Structure; Yeasts; cleavage factor; experimental study; human disease; mRNA Precursor; mRNA capping; public health relevance; stem

 DESCRIPTION (provided by applicant): Most eukaryotic messenger RNA precursors (pre-mRNAs) must undergo extensive co- transcriptional processing in the nucleus before they can be exported to the cytoplasm and function as mRNAs. The processing events include 5ʹ′-end capping, splicing, and 3ʹ′- end cleavage and polyadenylation. The 3'-end processing of most pre-mRNAs requires a large number of protein factors for its execution, including cleavage and polyadenylation specificity factor (CPSF), cleavage stimulation factor (CstF), cleavage factors I and II, and poly(A) polymerase (PAP). The 3'-end processing machinery in yeast has similarity to that in mammals, although there are also significant differences. Replication-dependent histone pre-mRNAs contain a conserved stem-loop near their 3ʹ′- end and employ a distinct machinery for its processing, although it shares some protein factors with the canonical pre-mRNA 3ʹ′-end processing machinery. mRNA 5ʹ′-end capping occurs early during transcription by RNA polymerase II, and it was generally believed that capping always proceeds to completion. We have recently discovered that the Rai1/DXO family of proteins are part of a mRNA capping quality surveillance mechanism. They can possess RNA 5ʹ′-end pyrophosphohydrolase (PPH) and decapping activities, and help remove incompletely capped mRNAs from cells. Despite the extensive studies on these mRNA processing and quality control factors, significant gaps remain in our knowledge of their molecular mechanisms of action. We will carry out structural studies on the protein factors and their complexes, and assess the structural observations by careful biochemical and functional experiments. The proposed project will greatly enhance our understanding of these important events in mRNA lifecycle.

 描述（由适用提供）：大多数真核生物Messenger RNA前体（MRNA前）必须在核us中进行广泛的转录处理，然后才能将其导出到细胞质并作为mRNA功能。处理事件包括5'末端封盖，拼接和3端裂解和聚腺苷酸化。大多数前MRNA的3'末端处理需要大量的蛋白质因子进行执行，包括裂解和聚腺苷酸化特异性因子（CPSF），裂解刺激因子（CSTF），裂解因子I和II和II和poly（a）聚合酶（PAP）。酵母中的3'末端加工机制与哺乳动物中的加工机械相似，尽管存在显着差异。依赖复制的组蛋白前MRNA在其3ʹ'- END附近包含一个保守的茎环，并且员工是其处理的独特机制，尽管它与规范前MRNA 3ʹ'-End加工机械共享某些蛋白质因子。 mRNA 5ʹ'-end上限发生在RNA聚合酶II转录期间的早期，并且通常认为封盖总是要完成。我们最近发现，RAI1/DXO蛋白质家族是mRNA限制质量监视机制的一部分。它们可以拥有RNA 5ʹ'-END焦道磷酸化酶（PPH）和decapting活性，并有助于去除细胞中未完全封闭的mRNA。尽管对这些mRNA处理和质量控制因素进行了广泛的研究，但我们对它们的分子作用机理的了解仍然存在很大的差距。我们将对蛋白质因子及其复合物进行结构研究，并通过仔细的生化和功能实验评估结构观察。拟议的项目将大大增强我们对mRNA生命周期中这些重要事件的理解。