TUT ase mediated degradation of histone mRNA

TUT 酶介导的组蛋白 mRNA 降解

• 批准号: 7893156
• 负责人: Michael Keith Slevin
• 金额: $ 2.52万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-07-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7893156
• 关键词: Affect; Biochemical; Cell Cycle; DNA Damage; DNA Replication Inhibition; DNA biosynthesis; Data; Gene Expression; Genetic Transcription; Genome Stability; Goals; Histones; Length; Mammals; Mediating; Messenger RNA; Modification; Pathway interactions; Phase; Polynucleotide Adenylyltransferase; Polyribosomes; Process; Protein Isoforms; Proteins; Recombinant Proteins; Recruitment Activity; Reporting; Research; Tail; Testing; UDPglucose-Hexose-1-Phosphate Uridylyltransferase; UV induced; Yeasts; chromosome loss; hydroxyurea; mRNA Transcript Degradation; novel; oligo(U); response

DESCRIPTION (provided by applicant): The replication dependent histones are expressed predominantly during S-phase. Inhibition of DNA replication by hydroxyurea or UV induced checkpoint pathways result in a reduction in histone transcription and rapid degradation of cytoplasmic histone mRNAs. Recently, the Marzluff lab has demonstrated that histone mRNA degradation requires a post-transcriptional modification that results in the addition of a oligo(U) tail to the 3' end of the histone mRNA. The oligo(U) tail ranges in size from 8-15 nts in length and its addition is required for histone mRNA degradation. Furthermore, our findings indicate that a non-canonical poly(A) polymerase. Terminal Uridyl Transferase (TUTase), is responsible for the oligouridylation of the histone mRNAs. The overall goals of the proposal are three fold. First, I will identify the TUTase isoform(s) responsible for histone mRNA oligouridylation and define the biochemical requirements for its enzymatic activity. Second, I will elucidate the mechanism(s) by which TUTase is recruited to histone mRNAs following inhibition of DNA replication and I will determine if proteins previously reported to be involved in histone mRNA degradation associate with and affect TUTase activity on histone mRNAs. I will also determine if initial oligouridylation of histone mRNA occurs on translationally active polysomes and investigate if TUTase remains associated with the mRNA as it is being degraded. Prior research has demonstrated that over or under expression of histones during S-phase contributes to chromosome loss and DNA damage in yeast and mammals, respectively. Of further importance is the mounting data that post-transcriptional mechanisms are a major determinant of gene expression. As a regulated class of messages, histone mRNAs present us a unique opportunity to identify and understand how the cell cycle regulates mRNA degradation, both as a normal set of processes, and as part of a response to checkpoint pathways important for genome stability.

描述（由申请人提供）：复制依赖性组蛋白主要在S期间表达。通过羟基脲或紫外线诱导的检查点途径抑制DNA复制导致组蛋白转录和细胞质组蛋白mRNA的快速降解。最近，Marzluff Lab表明，组蛋白mRNA降解需要转录后修饰，从而导致在组蛋白mRNA的3'末端添加寡核（U）尾巴。寡核（U）尾巴的长度为8-15 nt，其添加是组蛋白mRNA降解所必需的。此外，我们的发现表明非经典聚（A）聚合酶。末端尿苷转移酶（Tutase）负责组蛋白mRNA的寡苷化。该提案的总体目标是三倍。首先，我将确定负责组蛋白mRNA寡苷化的诱导酶同工型，并定义其酶活性的生化需求。其次，我将阐明在抑制DNA复制后，将促诱导酶募集到组蛋白mRNA的机制，并且我将确定蛋白质是否以前据报道与组蛋白mRNA降解有关并影响组蛋白对组蛋白mRNA的tut蛋白降解。我还将确定组蛋白mRNA的初始寡苷化是否发生在翻译活性的多个多综合体上，并研究诱导酶在降解时是否与mRNA保持相关。先前的研究表明，在S期期间，组蛋白的表达或以下是酵母和哺乳动物中的染色体丧失和DNA损伤。进一步的重要性是固定数据，即转录后机制是基因表达的主要决定因素。作为一系列受调节的消息，组蛋白mRNA为我们提供了一个独特的机会，可以识别和理解细胞周期如何调节mRNA降解，既是正常的过程，又是对检查点途径对基因组稳定性重要的响应的一部分。