Translational control of gene expression in fungi

真菌基因表达的翻译控制

• 批准号: 10737339
• 负责人: MATTHEW Steven SACHS
• 金额: $ 34.31万
• 依托单位: TEXAS A&M UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-01 至 2027-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10737339
• 关键词: Anabolism; Aspergillus fumigatus; Biotechnology; Cell physiology; Cells; Coccidioides posadasii; Code; Coupled; Cryptococcus neoformans; Data; Enzymes; Gene Expression; Genetic; Goals; Growth; Health; Human; In Vitro; Initiator Codon; Inositol; Inositol Metabolism Pathway; Knowledge; Mammalian Cell; Messenger RNA; Metabolic; Metabolic Pathway; Metabolism; Mission; Modeling; Molds; Molecular Mechanisms of Action; Names; Neurospora crassa; Open Reading Frames; Pathway interactions; Peptides; Peptidyltransferase; Physiological; Process; Production; Protein Biosynthesis; Proteins; RNA; Regulation; Regulatory Pathway; Reporter Genes; Research; Resolution; Ribosomes; Role; Scanning; Site; Specific qualifier value; Structure; System; Testing; Therapeutic; Translating; Translations; United States National Institutes of Health; Work; biochemical tools; biophysical tools; disorder control; fungus; gene product; improved; in vivo; inositol 3-phosphate; insight; mRNA Transcript Degradation; mRNA Translation; model organism; nanomachine; pathogenic fungus; response; small molecule; welfare

Summary Translation of mRNA is a central cellular process, but the mechanisms that control it are not fully understood. Up to 50% of eukaryotic mRNAs contain predicted upstream open reading frames (uORFs), but the roles of the vast majority of these uORFs remain undetermined. In some cases, we know that this additional translational capacity is evolutionarily conserved and serves critical functions in controlling gene expression. A special class of these conserved uORFs encodes peptides that stall protein synthesis in response to the presence of small metabolites. These nascent regulatory peptides act within the ribosome tunnel to arrest translation; by doing so, they control the production of enzymes important in metabolism. However, there remain important gaps in knowledge of the functions of uORFs. First, the mechanisms by which uORF-encoded peptides recognize small molecules and stall eukaryotic ribosomes to control gene expression remain unclear. Second, the extent to which uORFs are translated in cells under different conditions, the extent to which uORFs are evolutionarily conserved, and how and why the translation of particular uORFs controls gene expression, or if their translation serves other functions, is not known. To help bridge these gaps, we will determine the functions of a newly discovered conserved fungal uORF peptide named the inositol regulatory peptide (IRP). Our data indicate that the IRP regulates the expression of the first enzyme necessary for the synthesis of the important molecule inositol. We know that the IRP, while fungal in origin, can regulate reporter genes in mammalian cells as well as the fungus Neurospora crassa, in which we first discovered it. Using fungal and mammalian cell-free translation systems, we obtained direct evidence for translational control by the IRP. We will use both in vivo and in vitro approaches to determine the mechanism of action and physiological consequences of IRP function. In Aim 1, we will perform functional analyses to determine the mechanism of action of the IRP. In Aim 2, we will perform structural analyses to determine the mechanism of action of the IRP. Successful completion of the proposed work will provide mechanistic information that should significantly increase our understanding of translational control mechanisms that are generally important. It will provide new insights into regulatory and metabolic pathways that could be important for developing strategies to manipulate metabolism to improve human health and welfare.

概括 mRNA的翻译是一种中央细胞过程，但是控制它的机制尚未完全理解。 多达50％的真核mRNA包含预测的上游开放式阅读框（UORFS），但是该角色的作用 这些UORF的绝大多数仍未确定。在某些情况下，我们知道这种额外的翻译 能力在进化上是保守的，并且在控制基因表达方面具有关键功能。一个特殊的课程 在这些保守的UORF中，编码肽，使蛋白质合成响应小的肽 代谢物。这些新生的调节肽在核糖体隧道内作用以阻止翻译。这样， 他们控制着代谢中重要的酶的产生。但是，仍然存在重要差距 了解UORF的功能。首先，UORF编码的肽识别小的机制很小 分子和档位真核核糖体以控制基因表达，尚不清楚。第二，程度 UORF在不同条件下在细胞中翻译，UORF在进化上保守的程度， 以及特定UORFS的翻译如何以及为什么控制基因表达，或者它们的翻译是否服务于其他 功能，尚不清楚。为了弥合这些差距，我们将确定新发现的功能 保守的真菌UORF肽称为肌醇调节肽（IRP）。我们的数据表明IRP 调节重要分子肌醇所必需的第一种酶的表达。我们 知道IRP虽然真菌起源，但可以调节哺乳动物细胞中的报告基因以及真菌 Neurospora Crassa，我们首先发现了它。使用真菌和无细胞翻译系统， 我们获得了IRP转化控制的直接证据。我们将使用体内和体外方法 确定IRP功能的作用机理和生理后果。在AIM 1中，我们将表演 功能分析以确定IRP的作用机理。在AIM 2中，我们将进行结构分析 确定IRP的作用机理。成功完成拟议的工作将提供 机械信息应大大增加我们对翻译控制机制的理解 通常很重要。它将为可能是监管和代谢途径提供新的见解 对于制定操纵代谢以改善人类健康和福利的策略很重要。