Regulation of Mammalian mRNA decapping

哺乳动物 mRNA 脱帽的调控

• 批准号: 7729816
• 负责人: MEGERDITCH KILEDJIAN
• 金额: $ 32.83万
• 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 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7729816
• 关键词: Affect; Biochemical; Cells; Development; Disease; Erythrocytes; Funding; Gene Expression; Genes; Genetic Translation; Globin; Human; Hydrolysis; Life; Link; Malignant Neoplasms; Mammalian Cell; Mammals; Mediating; Mental Retardation; Messenger RNA; Modeling; Molecular; Motor Neurons; Nature; Neurons; Nuclear; Pathway interactions; Perception; Post-Transcriptional Regulation; Process; Proteins; Proto-Oncogenes; RNA Cap-Binding Proteins; Regulation; Role; Spinal Muscular Atrophy; Structure; Testing; Thalassemia; Therapeutic; Therapeutic Intervention; Tissues; Transcript; Translations; Work; X-Linked Mental Retardation; base; cell type; clinical phenotype; cytokine; decapping enzyme; drug candidate; genetic manipulation; insight; interest; mRNA Decay; mRNA Stability; mRNA capping; mRNA decapping; novel; novel strategies; novel therapeutics; nuclease; programs; protein function; public health relevance; therapeutic gene

DESCRIPTION (provided by applicant): The control of mRNA stability is a critical determinant in the post-transcriptional regulation of eukaryotic gene expression. Changes in mRNA stability can have profound consequences and may manifest as clinical phenotypes. This is perhaps best illustrated by the ability of aberrantly expressed proto-oncogenes that can give rise to malignancies and by the imbalanced 1 and 2 globin gene expression resulting in thalassemias. Despite the importance of mRNA stability in the control of gene expression, progress has only recently been made in the identification and characterization of the components that control mRNA turnover. We have focused our efforts on the study of nucleases and the pathways involved in mRNA decay in mammals, in particular, the two decapping enzymes, Dcp2 and DcpS. Dcp2 is the mRNA decapping enzyme that functions on capped mRNA while DcpS functions as the clearinghouse to hydrolyze the resulting cap structure following 34 to 54 decay of an mRNA. The long-term objective of this proposal is to understand the mechanisms that regulate mRNA decapping and mRNA decay in mammals and to utilize this information to control gene expression under normal and disease states. We have shown that Dcp2 is a transcript-specific decapping protein that is not uniformly expressed and is even undetectable in certain tissues indicating that there are as yet unknown decapping enzymes in mammals. We have also identified a protein implicated in X-linked mental retardation as a regulator of decapping. Furthermore, we have shown that DcpS is a modulator of the nuclear cap binding protein-mediated functions in addition to its role in mRNA turnover as well as the target substrate of a drug candidate for the treatment of spinal muscular atrophy. In this proposal, i) we will test the impact of Dcp2 and its absence on mRNA decay and identify the non-Dcp2 mRNA decapping enzyme in mammalian cells in Aim I; ii) characterize the mechanism by which the decapping regulator influences mRNA stability in Aim 2; and iii) assess the modulatory role of DcpS on cytoplasmic functions including mRNA stability and translation in Aim 3. This work will provide insights into a fundamental mechanism involved in the post-transcriptional control of gene expression and will provide a framework for novel approaches for therapeutic intervention in human disorders. PUBLIC HEALTH RELEVANCE: Our overall objective is to understand the precise controls involved in mRNA turnover and to utilize this information to regulate gene expression under normal and disease states. Decapping is a key step in the stability and ultimate demise of an mRNA. We will build on our ongoing functional studies of the Dcp2 and DcpS decapping enzymes in mammalian gene expression and their correlation to both mental retardation and spinal muscular atrophy. We will determine the impact of the presence, and surprising natural absence, of Dcp2 in mRNA decay, its regulation and the modulatory function of DcpS on cytoplasmic cap-binding protein processes. This work will provide insight into a fundamental mechanism involved in the post-transcriptional control of gene expression and could provide a framework in novel approaches for therapeutic intervention.

描述（由申请人提供）：mRNA稳定性的控制是真核基因表达转录后调控的关键决定因素。mRNA稳定性的变化可以产生深远的影响，并可能表现为临床表型。原癌基因的异常表达可能导致恶性肿瘤，而珠蛋白1和珠蛋白2基因表达不平衡导致地中海贫血，这可能是最好的说明。尽管mRNA稳定性在控制基因表达中的重要性，但直到最近才在控制mRNA转换的成分的鉴定和表征方面取得进展。我们主要致力于哺乳动物核酸酶和mRNA衰变途径的研究，特别是两种脱帽酶，Dcp2和dcp。Dcp2是mRNA脱帽酶，作用于被盖住的mRNA上，而dcpps则是在mRNA 34 - 54衰变后水解产生的帽状结构的交换中心。本研究的长期目标是了解哺乳动物mRNA脱冠和mRNA衰变的调控机制，并利用这些信息来控制正常和疾病状态下的基因表达。我们已经证明，Dcp2是一种转录特异性脱帽蛋白，在某些组织中不均匀表达，甚至无法检测到，这表明哺乳动物中存在未知的脱帽酶。我们还发现了一种与x连锁智力迟钝有关的蛋白质，它是脱帽的调节因子。此外，我们已经证明，除了在mRNA转换中发挥作用外，dcp还是核帽结合蛋白介导功能的调节剂，也是治疗脊髓性肌萎缩症的候选药物的靶底物。在本提案中，i)我们将测试Dcp2及其缺失对mRNA衰变的影响，并在Aim i中鉴定哺乳动物细胞中非Dcp2 mRNA脱帽酶；ii)描述脱帽调节因子影响Aim 2中mRNA稳定性的机制；iii)在Aim 3中评估dcp对细胞质功能的调节作用，包括mRNA的稳定性和翻译。这项工作将为基因表达转录后控制的基本机制提供见解，并将为人类疾病的治疗干预提供新方法框架。公共卫生相关性：我们的总体目标是了解mRNA转换的精确控制，并利用这些信息来调节正常和疾病状态下的基因表达。脱帽是mRNA稳定和最终消亡的关键步骤。我们将继续进行Dcp2和Dcp2脱帽酶在哺乳动物基因表达中的功能研究，以及它们与智力迟钝和脊髓性肌萎缩的关系。我们将确定Dcp2在mRNA衰变中的存在和令人惊讶的自然缺失的影响，它的调节以及Dcp2对细胞质帽结合蛋白过程的调节功能。这项工作将深入了解基因表达转录后控制的基本机制，并为治疗干预的新方法提供框架。