Determining the function and mechanism of the MALAT1 long non-coding RNA in co-transcriptional splicing

确定MALAT1长非编码RNA在共转录剪接中的功能和机制

• 批准号: 9911820
• 负责人: Prashant Bhat
• 金额: $ 5.05万
• 依托单位: CALIFORNIA INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-02-01 至 2022-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9911820
• 关键词: Animal Model; Antisense RNA; Automobile Driving; Binding; Biochemical; Bioinformatics; Breast; Breast Carcinoma; C-terminal; Categories; Cells; Chromosome Mapping; Colon; Colon Carcinoma; Data; Defect; Exhibits; Genes; Genetic Transcription; Genomic DNA; Genomics; Human; Label; Link; Lung; Lung Adenocarcinoma; MALAT1 gene; Malignant Neoplasms; Mammals; Mass Spectrum Analysis; Measures; Metabolic; Methods; Modeling; Molecular; Mus; Mutate; Neoplasm Metastasis; Nuclear; Oncogenes; Pancreas; Pancreatic carcinoma; Play; Polyadenylation; Primary carcinoma of the liver cells; Process; Prostate; Prostate carcinoma; Protein Splicing; Proteins; RNA; RNA Polymerase II; RNA Splicing; Regulation; Research Project Grants; Role; Structure; Testing; Therapeutic Intervention; Untranslated RNA; base; falls; insight; mRNA Precursor; mutant; overexpression; recruit; scaffold; transcriptome; tumor

PROJECT SUMMARY Many long non-coding RNAs (lncRNAs) have been shown to be mutated or aberrantly expressed in human cancers. One of the most common is a lncRNA called metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). MALAT1 represents an ideal model to study the role of lncRNAs in driving cancer because its overexpression is associated with mis-regulation of splicing in lung adenocarcinoma, breast, pancreatic, colon, prostate and hepatocellular carcinomas. Second, studies in animal models have shown that MALAT1 acts as an oncogene and promotes aggressive tumors and metastasis. Despite the clear importance of MALAT1 as a critical driver of many cancers, the functional role of MALAT1 in normal cellular conditions is unknown. Splicing in mammals occurs through a predominantly co-transcriptional mechanism such that splicing factors are recruited to nascent pre-mRNAs as they are being transcribed by RNA Polymerase II. Although it is clear that the C-terminal domain (CTD) of RNA Polymerase II (RNA PolII) is required for efficient splicing, how splicing factors are recruited co-transcriptionally and interact with RNA PolII is unknown. Recently, our group showed that MALAT1 localizes to the genomic DNA of the majority of actively transcribed RNA PolII genes and that this localization occurs in a transcriptionally dependent manner. Additionally, MALAT1 is known to localize to nuclear speckles, a nuclear compartment that is enriched for splicing factors. Based on these results, we hypothesized that MALAT1 might act as the elusive molecular link connecting RNA PolII and the splicing machinery that is required for efficient co- transcriptional recruitment and splicing of mammalian pre-mRNA. I hypothesize that MALAT1 acts as a molecular scaffold between RNA Polymerase II and splicing machinery to coordinate co-transcriptional splicing. Aim 1 of this proposal will characterize factors that directly bind to MALAT1 to coordinate co-transcriptional splicing. Aim 2 will identify if MALAT1 expression is directly linked to splicing defects. Finally, in Aim 3, the relationship between MALAT1 abundance and cancer will be explored. Taken together, these results would provide a transformative understanding of transcription and splicing, how they are coordinated in the cell, and how these processes might be disrupted through MALAT1 – a single lncRNA – to drive cancer.

项目总结 许多长的非编码RNA(LncRNAs)被证明是突变或异常表达的 在人类癌症中。其中最常见的一种是称为转移相关肺的lncRNA。 腺癌转录本1(MALAT1)。MALAT1是研究MALAT1作用的理想模型 LncRNAs在癌症中的作用，因为它的过度表达与剪接的错误调控有关 肺腺癌、乳腺癌、胰腺癌、结肠癌、前列腺癌和肝细胞癌。第二, 在动物模型中的研究表明，MALAT1作为癌基因发挥作用，促进攻击性 肿瘤和转移。尽管MALAT1作为许多癌症的关键驱动因素具有明显的重要性， MALAT1在正常细胞条件下的功能作用尚不清楚。 哺乳动物中的剪接是通过主要的共转录机制发生的，因此 剪接因子被招募到新生的前mRNAs，因为它们是由RNA聚合酶转录的 虽然很明显，RNA聚合酶II(RNA PolII)的C末端结构域(CTD)是必需的 为了有效的剪接，剪接因子是如何通过共转录方式招募并与RNA PolII相互作用的 是未知的。最近，我们的小组发现MALAT1定位于大多数人的基因组DNA 主动转录的RNA PolII基因，这种定位发生在转录依赖的 举止。此外，众所周知，MALAT1定位于核斑点，这是一种核隔膜 丰富的剪接因子。基于这些结果，我们假设MALAT1可能作为 连接RNA PolII和剪接机制的难以捉摸的分子链接是高效协同工作所必需的 哺乳动物Pre-mRNA的转录募集和剪接。 我推测MALAT1在RNA聚合酶II和 剪接机械以协调共转录剪接。本提案的目标1将描述 直接与MALAT1结合以协调共转录剪接的因子。目标2将确定是否 MALAT1的表达与剪接缺陷直接相关。最后，在目标3中， 我们将探讨MALAT1的丰度与癌症的关系。总而言之，这些结果将提供一个 对转录和剪接的变革性理解，以及它们在细胞中是如何协调的 这些过程是如何通过MALAT1--一种单一的lncRNA--被破坏而导致癌症的。