Regulation of Mammalian mRNA Decapping

哺乳动物 mRNA 脱帽的调控

• 批准号: 6821604
• 负责人: MEGERDITCH KILEDJIAN
• 金额: $ 29.94万
• 依托单位: RUTGERS, THE STATE UNIV OF N.J.
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6821604
• 关键词: RNA binding protein; RNA interference; enzyme substrate; gene expression; gene induction /repression; genetic regulation; hydrolysis; immunoprecipitation; messenger RNA; polymerase chain reaction; posttranscriptional RNA processing; protein structure function; transfection

DESCRIPTION (provided by applicant): The control of mRNA stability has recently emerged as a critical yet poorly understood determinant in the regulation of eukaryotic gene expression. Changes of mRNA stability can have profound consequences that may become manifest as clinical phenotypes. Malignancies that arise from aberrant expression of proto-oncogenes, and thalassemias, resulting from improper globin gene expression, are two examples indicating the importance of proper regulation of mRNA stability. Yet very little is known concerning the components that control mammalian mRNA turnover. We have devised an in vitro mRNA decay assay that recapitulates regulated mRNA turnover observed in cells and have shown that mammalian mRNA can be degraded from either the 5' or the 3' end. We have identified the two mammalian decapping enzymes, one of which is a homolog of the yeast Dcp2 protein and functions on capped mRNA. The second is a scavenger decapping activity, DcpS, which functions on the residual cap structure resulting from 3' to 5' decay of an mRNA. We have demonstrated human Dcp2 (hDcp2) is an RNA-binding protein whose activity is regulated by both the poly(A) tail and a potent inhibitor protein implicated in mental retardation. We have also observed that the human DcpS, in addition to its role in hydrolyzing the cap structure following mRNA decay, functions in a novel regulatory role to facilitate mRNA decay. The long term objective of this proposal is to understand the determinants and nucleases that regulate mRNA decay in mammals. The focus of this proposal is to: (AIM 1) investigate the regulatory mechanisms that control hDcp2 decapping; (AIM 2) determine the mechanism by which DcpS decapping enzyme functions to regulate mRNA decay; and (AIM 3) determine the contribution of the different pathways of mRNA decay involving the two decapping enzymes in vivo. This work will provide significant insights into a fundamental mechanism involved in the post transcriptional control of gene expression, that of mRNA turnover, and will provide a framework for novel approaches to regulate gene expression for therapeutic intervention.

描述（由申请人提供）：在调节真核基因表达的调节中，对mRNA稳定性的控制最近已成为一种关键但知之甚少的决定因素。 mRNA稳定性的变化可能会产生深远的后果，可能会形成临床表型。由原始基因的异常表达引起的恶性肿瘤和由全球基因表达不当引起的Thalassexias是两个例子，表明正确调控mRNA稳定性的重要性。然而，关于控制哺乳动物mRNA离职的组件，知之甚少。我们已经设计了一种体外mRNA衰变测定法，该测定概括了在细胞中观察到的调节的mRNA转换，并表明哺乳动物mRNA可以从5'或3'端降解。我们已经确定了两个哺乳动物的脱酶，其中一种是酵母DCP2蛋白的同源物，并在盖子上的mRNA上起作用。第二个是一种清道式销售活动DCP，其作用于mRNA的3'至5'衰减的残留盖结构。我们已经证明了人DCP2（HDCP2）是一种RNA结合蛋白，其活性受poly（a）尾巴和与智力低下有关的有效抑制剂蛋白的调节。我们还观察到，人类DCP除了在mRNA衰变后水解帽结构中的作用外，还起着新的调节作用，以促进mRNA衰变。该建议的长期目标是了解调节哺乳动物中mRNA衰减的决定因素和核酸酶。该提案的重点是：（目标1）研究控制HDCP2脱甲的调节机制； （AIM 2）确定DCPS将酶功能调节mRNA衰减的机制； （AIM 3）确定涉及体内两个decapping酶的mRNA衰变不同途径的贡献。这项工作将提供有关基因表达的转录后控制，mRNA转换的基本机制的重要见解，并将为调节治疗干预的基因表达的新方法提供一个框架。