Control of gene expression by RNA conformational change during transcription

转录过程中 RNA 构象变化控制基因表达

• 批准号: 8257805
• 负责人: George A Perdrizet
• 金额: $ 4.22万
• 依托单位: UNIVERSITY OF CHICAGO
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-01 至 2014-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8257805
• 关键词: Affect; Bacteria; Binding; Binding Sites; Biochemical Pathway; Biological; Biological Assay; Carrier Proteins; Cells; Collection; Complex; Coupled; DNA Sequence Rearrangement; DNA-Directed RNA Polymerase; Decision Making; Elements; Escherichia coli; Eukaryota; Evolution; Functional RNA; Gene Expression; Gene Expression Regulation; Genes; Genetic; Genetic Transcription; Goals; Human; In Vitro; Lead; Libraries; Maps; Membrane; Messenger RNA; Metabolism; Methods; Modeling; Organism; Positioning Attribute; Prokaryotic Cells; Proteins; RNA; RNA Folding; RNA Sequences; RNA chemical synthesis; Regulation; Regulatory Element; Research; Site; Structure; System; Transcript; Transcriptional Regulation; Translational Regulation; Translations; Variant; Vitamin B 12; aptamer; base; insight; pathogen; prevent; response; small molecule; tool

DESCRIPTION (provided by applicant): Regulation of gene expression by RNA structure occurs in both prokaryotic and eukaryotic organisms. One common mode of RNA based regulation in bacteria is riboswitch control. This type of gene regulation depends on the ability of one RNA sequence to form two different structures. Therefore, RNA conformational change is crucial to riboswitch regulation. Small molecule metabolite binding to an aptamer domain in nascent mRNA during transcription controls the final structure formed by that RNA. One structure represses the encoded proteins by terminating transcription or preventing translation. The alternative structure allows gene expression. One such riboswitch is the vitamin B12 btuB riboswitch of E. coli. This RNA controls the expression of an outer membrane B12 transport protein in response to the cellular concentration of vitamin B12. To accomplish this the same RNA sequence must form an 'on' or an 'off' structure dependent on B12 binding to the RNA. Traditionally, biophysical methods are used to study the formation and rearrangement of RNA structure in completed transcripts. However, riboswitch regulation occurs during transcription. To understand the mechanism of riboswitch function, folding and rearrangement will be studied during transcription. The benefit of this research is twofold. First it will provide a mechanistic understanding of the btuB system and insight into riboswitch based gene regulation in bacteria. Riboswitches are widespread genetic control elements. Second, the proposal will lay a general conceptual framework for the understanding of RNA conformational change during transcription. PUBLIC HEALTH RELEVANCE: This research will provide a mechanistic understanding of riboswitch function in bacteria by studying RNA folding during transcription, the same way it occurs in cells. This information is expected to give insight into the regulation of key biochemical pathways in human pathogens. It will also give a conceptual framework and new tools for understanding the mechanisms of more complex, non-coding RNA based regulatory systems in higher organisms.

描述（由申请人提供）：通过RNA结构调节基因表达发生在原核生物和真核生物中。细菌中基于RNA的一种常见调节模式是核糖开关控制。这种类型的基因调控依赖于一个RNA序列形成两种不同结构的能力。因此，RNA构象变化对核糖开关调控至关重要。小分子代谢物在转录过程中与新生mRNA的适体结构域结合，控制RNA形成的最终结构。一种结构通过终止转录或阻止翻译来抑制编码的蛋白质。替代结构允许基因表达。其中一种核糖开关是大肠杆菌的维生素B12 btuB核糖开关。这种RNA控制外膜B12转运蛋白的表达，以响应维生素B12的细胞浓度。为了实现这一目标，相同的RNA序列必须形成一个“开”或“关”的结构，这取决于B12与RNA的结合。传统上，生物物理方法用于研究RNA结构在完整转录本中的形成和重排。然而，核糖开关在转录过程中进行调控。为了了解核糖开关的功能机制，将研究转录过程中的折叠和重排。这项研究的好处是双重的。首先，它将提供对btuB系统的机制理解，并深入了解细菌中基于核糖开关的基因调控。核糖开关是广泛存在的遗传控制元件。其次，该提案将为理解转录过程中RNA构象变化奠定一个一般的概念框架。