Trans-splicing in C. Elegans

线虫中的反式剪接

• 批准号: 7417654
• 负责人: Thomas Blumenthal
• 金额: $ 36万
• 依托单位: UNIVERSITY OF COLORADO
• 依托单位国家: 美国
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-05-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7417654
• 关键词: Affect; Base Pairing; Binding; Biochemical; Bioinformatics; C-terminal; C. elegans genome; Caenorhabditis elegans; Class; Code; Complex; Condition; Consensus; DNA-Directed RNA Polymerase; Elements; Event; Exonuclease; Failure; Genes; Hand; Heterogeneous Nuclear RNA; In Vitro; Modeling; Mutation; Nature; Nuclear; Operon; Play; Polyadenylation; Process; Protein Binding; Proteins; RNA; RNA Interference; RNA Processing; RNA Splicing; Role; Role playing therapy; SF1; Site; Small Nuclear RNA; Small Nuclear Ribonucleoproteins; Specific qualifier value; Specificity; Spliced Genes; Spliced Leader RNA; Staging; System; Testing; Trans-Splicing; Transcript; Variant; chromatin immunoprecipitation; in vivo; insight; life history; mRNA Precursor; mutant; novel; prevent; promoter; protein function; research study; snRNP Structural Core Protein; stem; transcription termination

Operons are an important feature of the C. elegans genome. Their transcripts are polycistronic pre-mRNAs that get processed by 3' end formation and trans-splicing. These two evens occur in close proximity between operon genes. Although 3' end formation is generally accompanied by transcription termination, in operons it is not. We have identified the key sequences and many of the key trans-acting proteins and snRNAs responsible for carrying out these events, and we are determining what roles they play and how. The key sequence required for both the trans-splicing and for preventing transcription termination is the Ur element that occurs ~50 bp downstream of the 3' end cleavage site. We will determine what binds there. We are also studying the roles of the protein components of the snRNP that does this specialized transsplicing event. Functional studies involving mutants and RNAi of these components and biochemical studies in an in vitro splicing extract are proposed. We have discovered that one of these proteins is bound to a novel snRNA, Sm Y, currently the only snRNA whose function is not known. We will study the role of this RNA in trans-splicing and operon pre-mRNA processing. We have identified several proteins likely to play roles in 3' end formation and transcription termination as suppressors of a mutation that inserts a transcription termination site into the first gene of an operon. One of these proteins is an exonuclease, another is an SR protein, and three others all have a domain that indicates they perform their functions by binding directly to RNA polymerase. We will determine what functions these proteins have in 3' end formation. These studies should provide important new insight into how 3' end cleavage can occur without accompanying transcription termination.

操作子是C.线虫基因组它们的转录物是多顺反子前mRNA 通过3'末端形成和反式剪接来加工。这两件事发生得很近 操纵子基因之间的联系虽然3'末端的形成通常伴随着转录终止，但在 操纵子则不然。我们已经确定了关键序列和许多关键的反式作用蛋白， snRNA负责执行这些事件，我们正在确定它们扮演什么角色以及如何扮演。 反式剪接和防止转录终止所需的关键序列是Ur 在3'末端切割位点下游约50 bp处出现的元件。我们将决定什么约束那里。 我们也在研究snRNP蛋白质组分的作用，snRNP蛋白质组分进行这种专门的转剪接 活动涉及这些组分的突变体和RNAi的功能研究以及生物化学研究 在体外剪接提取物中。我们已经发现，这些蛋白质之一是结合到一个 新的snRNA，Sm Y，目前唯一的snRNA，其功能是未知的。我们将研究这一作用 RNA的反式剪接和操纵子前mRNA加工。我们已经确定了几种蛋白质， 在3'末端形成和转录终止中的作用，作为插入一个 转录终止位点插入操纵子的第一个基因。其中一种蛋白质是核酸外切酶， 另一种是SR蛋白，另外三种蛋白都有一个结构域，表明它们通过以下方式发挥功能： 直接与RNA聚合酶结合。我们将确定这些蛋白质在3'端有什么功能 阵这些研究应该提供重要的新的见解，如何3'端切割可以发生，而没有 伴随着转录终止。