Structural and Functional Studies of Mtr4 and Mtr4-mediated Complexes

Mtr4 和 Mtr4 介导的复合物的结构和功能研究

• 批准号: 9009671
• 负责人: SEAN J JOHNSON
• 金额: $ 25.03万
• 依托单位: UTAH STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-30 至 2020-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9009671
• 关键词: Address; Biochemical; Cell Nucleus; Cell physiology; Characteristics; Complex; Cytosol; Disease; Event; Excision; In Vitro; Individual; Lead; Link; Malignant Neoplasms; Mediating; Modeling; Molecular; Mutation; Neurodegenerative Disorders; Nuclear; Pathway interactions; Phosphodiesterase I; Play; Process; Protein Binding; Protein Subunits; Proteins; RNA; RNA Degradation; RNA Helicase; RNA Processing; Role; Structure; Substrate Interaction; Substrate Specificity; System; base; endonuclease; genetic analysis; helicase; in vivo; novel; prevent; public health relevance; research study

 DESCRIPTION (provided by applicant) The integrity and availability of cellular RNA is tightly regulated by a variety of RNA processing, turnover, and surveillance pathways. The eukaryotic exosome plays a major role in the processing and degradation of a wide variety of RNAs in both the nucleus and cytosol. Several protein factors associate with the exosome to identify appropriate RNA substrates and activate exosome activity. A major challenge is to understand the molecular details of how these proteins interact with RNA substrates and with each other to achieve substrate specificity. Notably, the only protein factor that is required for all known activities of the nuclear exosome i the RNA helicase, Mtr4. Given this central role in exosome activation, there is a critical need to understand how Mtr4 functions, how it interacts with RNA substrates, and how it mediates and is influenced by assembly of other exosome activating factors. Recent studies indicate that the arch domain of Mtr4 plays a previously unrecognized role in unwinding RNA substrates. The underlying basis for this observation is unclear, but is proposed to be a function of substrate interactions that connect the arch to the core helicase domains. The detailed interactions between Mtr4 and other complexes, such as the TRAMP complex, are also poorly understood. This project seeks to define the molecular basis for Mtr4 function by employing a variety of biochemical and structural approaches, combined with in vivo genetic analysis. The specific aims of this project are to (1) describe the role of the arch domain in RNA recognition and unwinding, and (2) characterize Mtr4 interactions with protein binding partners.

 描述（由申请人提供） 细胞RNA的完整性和可用性受到各种RNA加工的严格调节， 营业额和监视途径。真核细胞外泌体在细胞核和胞质溶胶中的各种RNA的加工和降解中起主要作用。几种蛋白质因子与外泌体结合以鉴定适当的RNA底物并激活外泌体活性。一个主要的挑战是了解这些蛋白质如何与RNA底物相互作用以及相互作用以实现底物特异性的分子细节。值得注意的是，核外泌体所有已知活动所需的唯一蛋白质因子是RNA解旋酶Mtr 4。鉴于这种在外泌体激活中的核心作用，迫切需要了解Mtr4如何发挥作用，它如何与RNA底物相互作用，以及它如何介导和受其他外泌体激活因子组装的影响。最近的研究表明，Mtr4的拱结构域在解旋RNA底物中起着以前未被认识到的作用。这一观察的基础尚不清楚，但建议是一个功能的基板相互作用，连接拱的核心解旋酶结构域。Mtr4与其他复合物（如TRAMP复合物）之间的详细相互作用也知之甚少。该项目旨在通过采用各种生物化学和结构方法，结合体内遗传分析来确定Mtr4功能的分子基础。该项目的具体目标是（1）描述arch结构域在RNA识别和解旋中的作用，以及（2）表征Mtr4与蛋白质结合伴侣的相互作用。