Interplay between transcription and translation

转录和翻译之间的相互作用

• 批准号: 9087943
• 负责人: Wayne Miles
• 金额: $ 18.68万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-05 至 2019-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9087943
• 关键词: 3' Untranslated Regions; Ablation; Address; Animals; Apoptosis; Binding Sites; Buffers; Cell Cycle; Cell Proliferation; Cell division; Cells; Complex; Computer Analysis; DNA Binding; DNA biosynthesis; Data; Development; Drosophila genus; E2F transcription factors; Employee Strikes; Environment; Evolution; Family; Family member; Gene Targeting; Genes; Genetic Screening; Genetic Transcription; Genetic Translation; Genetic study; Health; Human; Indium; Link; Malignant Neoplasms; Mediating; Messenger RNA; Metabolic Pathway; Mitosis; Modeling; Molecular; Mus; Mutation; Normal Cell; Outcome; Pattern; Phase; Post-Transcriptional Regulation; Process; Production; Proliferating; Protein Biosynthesis; Proteins; Proteome; Proteomics; RNA-Binding Proteins; Regulation; Research; Response Elements; Retinoblastoma; Role; S Phase; Structure of parenchyma of lung; Testing; Tissues; Transcript; Translational Regulation; Translations; United States; cancer cell; fly; in vivo; insight; mortality; mutant; neoplastic cell; novel; overexpression; research study; response; tool; transcription factor; tumor; tumorigenic

 DESCRIPTION (provided by applicant): A very precise control of cell proliferation is essential for normal animal development and the deregulation of cell division is a hallmark of cancer. The E2F transcription factors are integral components of the machinery regulating the mammalian division cycle. The role of E2F has been conserved throughout evolution. E2F co- ordinates the transcription of hundreds of genes that are needed for cells to divide and proliferate. In the two decades since E2F was first identified it has been assumed that activation of E2F-dependent transcription inevitably results in the increased synthesis of the encoded proteins. I have recently uncovered evidence of an additional layer of post-transcriptional regulation that acts broadly on a significant fraction of E2F-regulated transcripts, and that suppresses the translation of these mRNAs. Drosophila genetic studies show that two RNA-binding proteins, Pumilio and Nanos, functionally suppress E2F activity in vivo. Molecular studies have confirmed that the regulation of E2F/RB and Pumilio/Nanos proteins are intimately interconnected in both flies and humans, with mRNAs encoding activator E2Fs being suppressed via Pumilio response elements (PREs), and the transcription of Nanos and Pumilio genes being suppressed by E2F and RB family members. An explanation for these connections has emerged from "omic" studies. Our recent comparison of the transcriptional and proteomic changes associated with RB- mutation in mouse lung tissue revealed that although the transcription of E2F target genes were dramatically increased upon RB mutation, very few of these genes displayed protein level changes. Strikingly, an unbiased analysis of the post-transcriptional motifs within mRNAs that are transcriptionally upregulated in RB mutant tissues, without a similar increase in protein levels, found that PRE-motifs are the most significantly enriched. Furthermore analysis of mRNA sequences upregulated in retinoblastoma tumors shows that mRNAs from >50% of E2F-regulated genes contain putative PRE motifs. This proposal will test the hypothesis that Pumilio and Nanos proteins provide a tier of post- transcriptional regulation that acts on a broad swath of E2F-induced transcripts. I will determine which E2F- induced transcripts are suppressed in this manner, when they are regulated, and will investigate the impact of this regulation on protein levels. Deregulated E2F activity drives the proliferation of many human cancers. I will discover whether the control mediated by Pumilio and Nanos buffers RB mutant cells from increases in E2F-dependent transcription, and I will determine whether this apparatus is preserved or lost in cancer cells. Collectively these experiments will define a novel regulatory mechanism that limits the expression of E2F- transcibed genes.

 描述（由申请人提供）：非常精确地控制细胞增殖对于正常动物发育至关重要，而细胞分裂的失调是癌症的标志。 E2F 转录因子是调节哺乳动物分裂周期的机制的组成部分。 E2F 的作用在整个进化过程中一直得到保留。 E2F 协调细胞分裂和增殖所需的数百个基因的转录。自 E2F 首次被发现以来的二十年里，人们一直认为 E2F 依赖性转录的激活不可避免地会导致所编码蛋白质的合成增加。我最近发现了额外一层转录后调控的证据，该调控广泛作用于 E2F 调控转录本的很大一部分，并抑制翻译 这些 mRNA。果蝇遗传学研究表明，两种 RNA 结合蛋白 Pumilio 和 Nanos 在体内功能性抑制 E2F 活性。分子研究证实，E2F/RB 和 Pumilio/Nanos 蛋白的调节在果蝇和人类中密切相关，编码激活剂 E2F 的 mRNA 通过 Pumilio 反应元件 (PRE) 被抑制，Nanos 和 Pumilio 基因的转录被 E2F 和 RB 家族成员抑制。对这些联系的解释来自于“组学”研究。我们最近对小鼠肺组织中与 RB 突变相关的转录和蛋白质组变化进行了比较，结果表明，尽管 RB 突变后 E2F 靶基因的转录显着增加，但这些基因中很少有显示蛋白质水平变化。引人注目的是，对 RB 突变组织中转录上调的 mRNA 内的转录后基序进行无偏分析，发现 PRE 基序最显着富集，而蛋白质水平没有类似的增加。此外，对视网膜母细胞瘤肿瘤中上调的 mRNA 序列的分析表明，超过 50% 的 E2F 调控基因的 mRNA 含有推定的 PRE 基序。该提案将检验以下假设：Pumilio 和 Nanos 蛋白提供一层转录后调控，作用于广泛的 E2F 诱导转录本。我将确定哪些 E2F 诱导的转录物在受到调节时以这种方式受到抑制，并将研究这种调节对蛋白质水平的影响。 E2F 活性失调会导致许多人类癌症的扩散。我将发现 Pumilio 和 Nanos 介导的控制是否会缓冲 RB 突变细胞 E2F 依赖性转录的增加，并且我将确定该装置在癌细胞中是否保留或丢失。总的来说，这些实验将定义一种限制 E2F 转录基因表达的新调控机制。