Biochemical & Genetic Analysis of Low Complexity Domains in RNA-binding protein biology

生化

• 批准号: 9158657
• 负责人: Daniel Reines
• 金额: $ 32.53万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9158657
• 关键词: Affect; Age; American; Amino Acids; Amyloid; Attention; Basic Science; Binding; Biochemical; Biochemical Genetics; Biochemistry; Biological; Biological Process; Biology; Cell Survival; Cell physiology; Cells; Characteristics; Code; Complex; DNA Packaging; DNA-Directed RNA Polymerase; Disease; Elements; Enzymes; Filament; Frequencies; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Glucose; Goals; Heterogeneous-Nuclear Ribonucleoproteins; Human; Hydrogels; Inclusion Bodies; Informatin; Lead; Metabolism; Modeling; Molecular; Molecular Genetics; Mutagenesis; Nerve Degeneration; Neurodegenerative Disorders; Nucleosomes; Pathology; Play; Polyadenylation Pathway; Polymers; Population; Process; Protein Dynamics; Proteins; Public Health; Quality Control; RNA; RNA Binding; RNA Polymerase II; RNA Processing; RNA Recognition Motif; RNA-Binding Proteins; RNA-Protein Interaction; Recording of previous events; Role; Saccharomyces cerevisiae; Small Nucleolar RNA; Starvation; Structure; System; Testing; Transcript; Ursidae Family; Work; Yeasts; abstracting; base; cell type; dimer; genetic analysis; helicase; human disease; in vitro testing; in vivo; nuclease; operation; polyglutamine; polymerization; prion-like; protein TDP-43; protein complex; protein function; prototype; self assembly; success; termination factor; tool; transcription termination

Summary/Abstract Many proteins involved in gene expression contain a low complexity domain that itself lacks secondary structure but which can form intermolecular polymers known as amyloid, a stable structure that can organize into filaments and hydrogels. Some of the proteins that bear such intrinsically unstructured domains interact with RNA polymerase II or the RNA produced during transcription. Indeed, this structural feature is unusually over-represented in cellular RNA- binding proteins. A current hypothesis suggests that these low complexity domains are proteinaceous switches that, with their adjacent folded portions such as RNA recognition motifs, assemble into cellular compartments that handle and process RNA. Excellent examples include yeast Nab3 and Nrd1 which are factors needed for termination of short transcripts such as snRNAs and snoRNAs. Similarly, potential amyloid forming domains that couple mRNA polyadenylation to termination at the end of protein coding genes are seen in Pcf11, Hrp1, and Rat1. Low complexity self-assembling domains are causally implicated in human diseases, particularly neurodegenerative pathologies in which aberrant cellular inclusions are a common characteristic. A leading model is that the normal propensity for aggregation of RNA-binding proteins can go awry, leading to toxic oligomeric and polymeric assemblies that are associated with cellular damage. Yet we have a poor understanding of the normal reversible function of these domains and why their aggregation can become toxic. The long-term goal of the project is to understand what amyloid forming domains provide for the function of RNA binding proteins; particularly those involved in terminating transcription of RNA polymerase II. The working hypothesis is that conditional polymerization of these proteins is a key part of how they operate. One model is that these proteins enshroud nascent RNA in a specific manner for presentation to the enzymes of termination and processing such as helicases and nucleases; perhaps in the way nucleosomes package DNA. The focus of this work is on RNA- binding, transcription termination factors in yeast where their involvement in the termination of transcription is fairly well understood. All possess low complexity domains that can potentially oligomerize. The prototype is the yeast hnRNP-like protein Nab3 that bears a polyglutamine-rich, self-assembly domain essential for cell viability and important for transcription termination. This project tests the role of these domains in the transcription termination machinery with respect to: 1) their amyloid forming potential, 2) the need for them for cell viability, and 3) their requirement for termination. Success in these aims will lead to new mechanistic models of how these RNA-protein interactions lead to productive and accurate gene expression.

许多参与基因表达的蛋白质都含有一个低复杂性结构域， 它本身缺乏二级结构，但可以形成称为淀粉样蛋白的分子间聚合物， 可以组织成细丝和水凝胶的稳定结构。一些具有这种功能的蛋白质 本质上非结构化的结构域与RNA聚合酶II或RNA聚合酶II过程中产生的RNA相互作用。 转录。事实上，这种结构特征在细胞RNA结合中异常地过度表现。 proteins.目前的一种假说认为，这些低复杂性结构域是蛋白质的， 开关，其与它们的相邻折叠部分如RNA识别基序一起组装成细胞 处理和加工RNA的细胞。很好的例子包括酵母Nab 3和Nrd 1， 是短转录物如snRNA和snoRNA终止所需的因子。同样地， 潜在的淀粉样蛋白形成结构域，其将mRNA多聚腺苷酸化偶联到末端的终止， 蛋白质编码基因见于Pcf 11、Hrp 1和Rat 1。低复杂度自组装结构域 与人类疾病，特别是神经退行性病变有因果关系， 异常的细胞内含物是一个共同的特征。一个主要的模型是， RNA结合蛋白的聚集可能会出错，导致有毒的寡聚体和多聚体 与细胞损伤相关的组装。但我们对它的理解却很有限。 这些结构域的正常可逆功能，以及为什么它们的聚集会变得有毒。 该项目的长期目标是了解淀粉样蛋白形成域提供了什么 RNA结合蛋白的功能;特别是那些参与终止RNA转录的蛋白 聚合酶II。工作假设是，这些蛋白质的条件聚合是关键， 他们如何运作的一部分。一种模型是，这些蛋白质以特定的方式包裹新生RNA。 用于呈递给终止酶和加工酶如解旋酶的方式， 核酸酶;也许是核小体包装DNA的方式。这项工作的重点是RNA结合， 酵母中的转录终止因子，其中它们参与转录的终止， 相当好理解。所有这些都具有低复杂性结构域，可能会寡聚化。的 原型是酵母hnRNP样蛋白Nab 3，其具有富含聚谷氨酰胺的自组装 结构域对细胞活力至关重要，对转录终止也很重要。该项目测试 这些结构域在转录终止机制中的作用涉及：1）它们的淀粉样蛋白 形成潜力，2）它们对细胞活力的需要，和3）它们对终止的需要。 这些目标的成功将导致这些RNA-蛋白质相互作用的新机制模型 导致生产性和精确基因表达。