Spliceosomal small nuclear ribonucleoproteins in trypansomes: Genomwide analysis of role of U1 snRPN proteins in mRNA processing

锥虫中的剪接体小核核糖核蛋白：U1 snRPN 蛋白在 mRNA 加工中作用的全基因组分析

• 批准号: 213586145
• 负责人: Professor Dr. Albrecht Bindereif
• 金额: --
• 依托单位: Institut für Biochemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2015-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/213586145?language=en
• 关键词: Spliceosomal; small; nuclear; ribonucleoproteins; trypansomes

All protein-coding genes in trypanosomes are expressed as polycistronic primary transcripts that have to be processed by coupled trans splicing and polyadenylation to yield mature mRNAs. In addition, only very few genes are known to undergo cis splicing of an internal intron. Trans splicing requires specifically the Spliced Leader (SL) RNA, which adds its 5’-terminal 39-nucleotide miniexon to each of the protein-coding exons. On the other hand, the U1 small nuclear ribonucleoprotein (snRNP) is considered a component acting specifically during cis splicing of the very few internal introns. We have recently characterized the U1 snRNP from Trypanosoma brucei, an unusual RNP with a minimal U1 snRNA, U1-70K, U1C, and a protein component (U1-24K) not found in well-characterized U1 snRNPs from other systems. Evidence from several studies including our own has accumulated that argues for the existence of several different RNP complexes of the U1 snRNA and for U1-independent roles of their protein components, linking cis and trans splicing as well as polyadenylation. We propose to study in detail the contributions of individual U1 snRNP proteins to and the potential links between these principal mRNA processing reactions in trypanosomes, using systematic epitope tagging, RNAi knockdown, as well as genomewide RNA-binding (iCLIP) and deep-sequencing approaches.

锥虫中的所有蛋白质编码基因均表达为多顺反子初级转录本，必须通过耦合反式剪接和多聚腺苷酸化进行加工才能产生成熟的 mRNA。此外，已知只有极少数基因会经历内部内含子的顺式剪接。反式剪接特别需要剪接前导 (SL) RNA，它将其 5' 端 39 核苷酸小外显子添加到每个蛋白质编码外显子上。另一方面，U1 小核核糖核蛋白 (snRNP) 被认为是在极少数内部内含子顺式剪接过程中特异性发挥作用的成分。我们最近对布氏锥虫的 U1 snRNP 进行了表征，这是一种不寻常的 RNP，具有最小的 U1 snRNA、U1-70K、U1C 和蛋白质成分 (U1-24K)，而在其他系统的充分表征的 U1 snRNP 中未发现。包括我们自己在内的多项研究积累的证据表明，U1 snRNA 存在几种不同的 RNP 复合物，并且其蛋白质成分具有独立于 U1 的作用，连接顺式和反式剪接以及多聚腺苷酸化。我们建议使用系统表位标记、RNAi 敲除以及全基因组 RNA 结合 (iCLIP) 和深度测序方法，详细研究单个 U1 snRNP 蛋白对锥虫中这些主要 mRNA 加工反应的贡献以及之间的潜在联系。