Molecular mechanism of mTORC1-dependent translation and ribosome biogenesis

mTORC1依赖性翻译和核糖体生物发生的分子机制

基本信息

批准号：
8887569
负责人：
Ken Inoki
金额：
$ 29.02万
依托单位：
UNIVERSITY OF MICHIGAN AT ANN ARBOR
依托单位国家：
美国
项目类别：
财政年份：
2015
资助国家：
美国
起止时间：
2015-04-15 至 2018-12-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8887569
关键词：
5&apos Untranslated Regions Ablation Address Animal Model Antineoplastic Agents Binding Biochemistry Biogenesis Biological Cell Proliferation Cell physiology Clinical Trials Complex Couples Data Defect Development Genes Genetic Translation Goals Growth Factor High-Throughput RNA Sequencing Indium Lead Malignant - descriptor Malignant Neoplasms Malignant neoplasm of prostate Mediating Messenger RNA Metastatic Prostate Cancer Modeling Molecular Molecular Biology Mus Nutrient PTEN gene Phosphorylation Phosphotransferases Play Production Prostate Protein Biosynthesis Protein Kinase Proteins Proteomics Pyrimidine RNA RNA Recognition Motif Regulation Ribosomes Role Signal Pathway Signal Transduction Site Staging Testing Tissues Translation Initiation Translations Tumor Suppressor Proteins Untranslated Regions cancer cell cancer therapy cancer type cell growth cell growth regulation in vivo inhibitor/antagonist insight mTOR protein migration mouse model new therapeutic target novel novel therapeutic intervention prostate cancer cell line public health relevance response scaffold tumor tumor progression uncontrolled cell growth

项目摘要

DESCRIPTION (provided by applicant): The mammalian target of rapamycin complex 1 (mTORC1) is an evolutionarily conserved multi- protein kinase complex that couples nutrient and growth factor sensing to regulate a wide array of essential cellular processes. mTORC1 stimulates protein synthesis and ribosome biogenesis, which are vital cellular processes that regulate cell growth and proliferation. Hyperactivation of mTORC1 signaling is found in many types of cancer cells and leads to aberrant increases in protein synthesis and uncontrolled cell proliferation. Despite the positive roles of mTORC1 in enhancing general cap- dependent translation through eIF4E activation, recent studies reveal mTORC1 preferentially stimulates a subset of mRNAs, including those that encode proteins required for translation, and cell growth, proliferation, and invasion. Interestingly, these mRNAs possess pyrimidine-enriched sequences (PES) such as 5'TOP in their 5'UTRs that are thought to play important roles in their expression. However, the molecular mechanisms by which mTORC1 primarily facilitates the translation of a subset of those mRNAs remain elusive. We have discovered a novel mTORC1 substrate, LARP1 that directly interacts with the PES in the 5'UTRs of 5' TOP mRNAs. Our preliminary data suggest that LARP1 functions not only as a molecular switch to regulate PES- containing mRNA translation in response to mTOR activity, but also as a regulator for mTORC1 to phosphorylate 4EBP1 and S6K1 on translationally-competent mRNAs. Knockdown of LARP1 significantly reduces translation of mRNAs that interact with LARP1 and dramatically inhibits ribosome biogenesis and cell proliferation in various cancer cells. We propose that LARP1 is an atypical mTORC1 substrate that regulates the translation of specific PES mRNAs and enhances their mTORC1-dependent translation. We will explore the molecular mechanisms by which mTORC1- dependent phosphorylation of LARP1 contributes to the translation of its interacting mRNAs. Second, we will determine the functional importance of the 5'UTR PES motif enriched in LARP1-bound mRNAs. Finally, we will explore the in vivo functions of LARP1 as well as pathophysiological role of LARP1 in PI3K-Akt-mTORC1-mediated cancer development in animal models. We will accomplish our goals by exploiting a multifaceted but integrated approach combining biochemistry, molecular biology, proteomics, high-throughput RNA sequencing, and mouse models. By elucidating the molecular mechanisms of mTORC1-LARP1-depenent translation, our proposed studies will provide new insights into the regulations of mTORC1-mediated translation and lead to new therapeutic approaches for cancer that target downstream effectors of mTORC1 activity.

描述（由申请人提供）：雷帕霉素复合物 1 (mTORC1) 的哺乳动物靶点是一种进化上保守的多蛋白激酶复合物，它耦合营养物和生长因子感应来调节多种重要的细胞过程，刺激蛋白质合成和核糖体生物发生。，这是调节细胞生长和增殖的重要细胞过程 mTORC1 信号传导过度激活存在于许多类型的癌细胞中，并导致蛋白质合成异常增加和细胞失控。尽管 mTORC1 在通过 eIF4E 激活增强一般帽依赖性翻译方面发挥着积极作用，但最近的研究表明，mTORC1 优先刺激一部分 mRNA，包括编码翻译、细胞生长、增殖和侵袭所需蛋白质的 mRNA。 mTORC1 的 5'UTR 中含有富含嘧啶的序列 (PES)，例如 5'TOP，这些序列被认为在其表达中发挥重要作用。然而，mTORC1 主要通过的分子机制。促进新型 mTORC1 底物 LARP1 的翻译，LARP1 直接与 5' TOP mRNA 的 5'UTR 中的 PES 相互作用。我们的初步数据表明，LARP1 不仅作为分子子集开关来调节含有 PES 的 mRNA 翻译。 mTOR 活性，而且还作为 mTORC1 的调节剂，磷酸化具有翻译能力的 4EBP1 和 S6K1 LARP1 的敲低显着降低了与 LARP1 相互作用的 mRNA 的翻译，并显着抑制各种癌细胞中的核糖体生物合成和细胞增殖。我们认为 LARP1 是一种非典型 mTORC1 底物，可调节特定 PES mRNA 的翻译并增强其 mTORC1 依赖性。我们将探索 LARP1 的 mTORC1 依赖性磷酸化促进其相互作用 mRNA 翻译的分子机制。最后，我们将在动物模型中探索 LARP1 的体内功能以及 LARP1 在 PI3K-Akt-mTORC1 介导的癌症发展中的病理生理学作用。通过利用生物化学、分子生物学、蛋白质组学、高通量 RNA 测序和小鼠模型相结合的多方面综合方法来阐明其分子机制。 mTORC1-LARP1 依赖的翻译，我们提出的研究将为 mTORC1 介导的翻译调节提供新的见解，并带来针对 mTORC1 活性下游效应器的癌症新治疗方法。