Genetic & Molecular Studies of Nematode mRNA Degradation

遗传

• 批准号: 7533105
• 负责人: Philip Anderson
• 金额: $ 40.21万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-05-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7533105
• 关键词: Animal Model; Animals; Binding; Biochemical; Biological; Biological Process; Caenorhabditis elegans; Categories; Cell physiology; Cells; Eukaryota; Eukaryotic Cell; Frameshift Mutation; Gene Expression; Gene Silencing; Genes; Goals; Growth and Development function; Hereditary Disease; Homeostasis; Human; Mammalian Cell; Mediating; Messenger RNA; Molecular; Molecular Genetics; Nature; Nematoda; Nonsense Codon; Nonsense-Mediated Decay; Normal Cell; Phosphorylation; Physiological; Point Mutation; Process; Property; Protein Dephosphorylation; Proteins; RNA Interference; Range; Regulation; Research; Role; Structure; Terminator Codon; Testing; Trans-Activators; Translations; Work; falls; in vivo; mRNA Decay; mRNA Transcript Degradation; mutant; research study

DESCRIPTION (provided by applicant): The broad aims of our research are to understand the molecular mechanisms and physiological consequences of regulating eukaryotic gene expression by post-transcriptional processes. A large amount of important biological regulation occurs post-transcriptionally, but many of the mechanisms are not well understood. We will study selective mRNA degradation, the processes by which specific mRNAs are actively eliminated from cells. Regulated turnover of mRNAs profoundly influences gene expression, and our broad goals are to understand the mechanisms and consequences of that regulation. We focus on the accelerated degradation of mRNAs that contain premature translation termination codons. Messenger RNAs that contain premature stop codons are degraded more rapidly than their wild-type counterparts, a phenomenon termed "nonsense-mediated mRNA decay" (NMD). NMD occurs in all eukaryotes tested, and its action substantially impacts human genetic disease. Approximately one third of all sequenced point mutations that cause human genetic disease are nonsense or frameshift mutations, and most of these are known or predicted to elicit NMD of the mutant mRNA. We will study seven C. elegans genes required for NMD (smg-1 through smg-7) and will investigate their genetic and molecular properties. Our work falls into three broad categories: (1) investigating the molecular mechanisms of NMD; (2) investigating the relationship of NMD to RNA interference; and (3) investigating the biological function of NMD in wild-type animals. Our Specific Aims are: 1. We will investigate the structure of mRNPs containing premature translation termination codons. Such mRNPs differ from those not containing premature stop codons by selectively binding the SMG-2 protein. 2. We will study the roles of SMG-2 phosphorylation and dephosphorylation in NMD. 3. We will investigate a recently discovered relationship between NMD and RNAi. We will test whether NMD contributes to gene silencing via endogenous RNAi. 4. We will identify most or all of the endogenous mRNA targets of NMD. Our long-range goals are to understand both the molecular mechanisms of mRNA turnover and the biological roles of NMD. Our experiments contribute to these goals by identifying proteins that are required for NMD, by describing their biochemical activities in vivo, and by investigating the role of NMD during normal growth and development.

描述（由申请人提供）：我们研究的主要目标是了解通过转录后过程调节真核基因表达的分子机制和生理后果。大量重要的生物调控发生在转录后，但许多机制尚不清楚。我们将研究选择性 mRNA 降解，即特定 mRNA 从细胞中主动消除的过程。 mRNA 周转的调节深刻影响基因表达，我们的总体目标是了解这种调节的机制和后果。我们关注包含过早翻译终止密码子的 mRNA 的加速降解。含有过早终止密码子的信使 RNA 比野生型对应物降解得更快，这种现象称为“无义介导的 mRNA 衰减”(NMD)。 NMD 存在于所有测试的真核生物中，其作用对人类遗传疾病有重大影响。导致人类遗传疾病的所有已测序点突变中，大约有三分之一是无义突变或移码突变，其中大多数已知或预测会引发突变 mRNA 的 NMD。我们将研究 NMD 所需的 7 个秀丽隐杆线虫基因（smg-1 至 smg-7），并研究它们的遗传和分子特性。我们的工作分为三大类：（1）研究NMD的分子机制； (2)研究NMD与RNA干扰的关系； (3)研究NMD在野生动物中的生物学功能。我们的具体目标是： 1. 我们将研究含有过早翻译终止密码子的 mRNP 的结构。 此类 mRNP 与不包含提前终止密码子的 mRNP 不同，其选择性结合 SMG-2 蛋白。 2. 我们将研究SMG-2磷酸化和去磷酸化在NMD中的作用。 3. 我们将研究最近发现的 NMD 和 RNAi 之间的关系。我们将测试是否 NMD 通过内源性 RNAi 促进基因沉默。 4.我们将鉴定NMD的大部分或全部内源mRNA靶点。 我们的长期目标是了解 mRNA 周转的分子机制和 NMD 的生物学作用。我们的实验通过鉴定 NMD 所需的蛋白质、描述其体内生化活性以及研究 NMD 在正常生长和发育过程中的作用来实现这些目标。