Translational Regulation of Embryonic Stem Cell Self-Renewal by Pumlio Proteins

Pumlio 蛋白对胚胎干细胞自我更新的翻译调控

• 批准号: 9213714
• 负责人: Haifan Lin
• 金额: $ 36.85万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9213714
• 关键词: 3' Untranslated Regions; Binding; Binding Proteins; Biochemical; Biological Process; Caenorhabditis elegans; Cell Differentiation process; Cells; Complex; Data; Degenerative Disorder; Developmental Delay Disorders; Drosophila genus; Embryo; Embryonic Development; Epigenetic Process; Feedback; Gene Expression; Gene Expression Regulation; Genes; Genetic Transcription; Genomics; Knowledge; Learning; Mediating; Messenger RNA; MicroRNAs; Molecular; Molecular Profiling; Morula; Mus; Pathway interactions; Post-Transcriptional Regulation; Process; Proteins; Proteomics; RNA; Regulation; Regulon; Reporting; Repression; Research; Role; Signal Transduction; Site; Specificity; Spermatogenesis; Stem cells; System; TP53 gene; Testing; Testis; Tissues; Transcriptional Regulation; Translational Regulation; Translations; Work; cancer prevention; cancer therapy; crosslinking and immunoprecipitation sequencing; embryonic stem cell; epigenetic regulation; germline stem cells; mammalian genome; mutant; nano; novel; pluripotency; ribosome profiling; self-renewal; stem cell biology; stem cell division; stem cell fate

Project Summary Stem cells are defined by their unique ability to self-renew meanwhile producing numerous differentiated cells. How the self-renewal of stem cells is regulated is a central question in stem cell biology. In recent years, exciting progress has been made in understanding niche signaling and epigenetic/transcriptional regulation of stem cell self-renewal. However, much less is known about translational regulation of this process. Among a small number of studies on translational regulation, most of them are focused on the miRNA-mediated mechanism, which fine-tunes the temporal- and tissue-specificity of gene expression. Little, if any, is known about whether any translational regulator serves as a key regulator of the stem cell fate in mammalian systems. Recent work from my lab indicates that we have discovered two key translational regulators in mice, called Pumilio (Pum) 1 and Pum 2, that are essential in defining the stem cell fate. Both Pum1 and Pum2 are expressed in mouse embryonic stem cells (mESCs) and early embryos, targeting 1,947 and 437 mRNAs in mESCs, respectively. Pum1-Pum2 double mutants are developmentally delayed at the morula stage and lethal by e8.5; and Pum1-Pum2 double mutant ESCs fail to self-renew. These exciting findings led us to hypothesize that Pum proteins are key regulators of ESC self-renewal and thus early embryogenesis. To systematically test this hypothesis and to explore the role of translational regulation in mammalian stem cells, I propose to investigate the functions of Pum-mediated translational regulation in mESCs via the following aims: (1) determine the auto- and inter-regulatory effect of Pum1 and Pum2 in ESCs to reveal a novel circuitry of gene regulation composed of auto- and inter-regulatory negative feedback loops and how this circuitry regulates ESC pluripotency, self-renewal, and differentiation; (2) use combined genomic and proteomic approaches to determine how Pum1 and Pum2 regulate their many target mRNAs in ESCs and how some of the target mRNAs contribute to ESC pluripotency, self-renewal, and differentiation; (3) determine how Pum1 and Pum2 interact with other proteins to achieve their regulation of target mRNAs in ESCs. The proposed study, if achieved, should significantly advance our knowledge on the gene regulation of stem cell self-renewal. Moreover, it should reveal novel regulatory paradigms and mechanisms of post-transcriptional regulation as mediated by Pum proteins that are unique to mammalian systems.

项目摘要 干细胞的定义是它们独特的自我更新能力，同时产生大量的 分化细胞干细胞的自我更新是如何调控的是干细胞研究的核心问题 细胞生物学近年来，在理解生态位信号方面取得了令人兴奋的进展 和干细胞自我更新的表观遗传/转录调节。然而， 关于这个过程的翻译调控。在为数不多的翻译研究中， 调节，其中大多数集中在miRNA介导的机制，微调 基因表达时间和组织特异性。对于是否存在这种情况，我们知之甚少（如果有的话） 翻译调节子是哺乳动物系统中干细胞命运的关键调节子。 我的实验室最近的工作表明，我们已经发现了两个关键的翻译调节因子， Pumilio（Pum）1和Pum 2小鼠，它们在确定干细胞命运方面至关重要。两 Pum 1和Pum 2在小鼠胚胎干细胞（mESC）和早期胚胎中表达， 分别靶向mESC中的1，947和437个mRNA。Pum 1-Pum 2双突变体是 在桑椹胚期发育延迟，致死性为e8.5; Pum 1-Pum 2双 突变的ESC不能自我更新。这些令人兴奋的发现使我们假设Pum蛋白 是ESC自我更新和早期胚胎发生的关键调节因子。为了系统地测试 这一假设，并探讨哺乳动物干细胞中的翻译调控的作用，我 建议通过以下途径研究Pump介导的mESCs翻译调控的功能： 以下目的：（1）确定Pum 1和Pum 2在ESCs中的自我调节和相互调节作用， 揭示了一种新的基因调控回路，由自我和相互调节的负 反馈循环以及该电路如何调节ESC多能性、自我更新和 分化;（2）使用组合的基因组和蛋白质组学方法来确定Pum 1 Pum 2和Pum 2调节ESCs中的许多靶mRNA， 有助于ESC的多能性、自我更新和分化;（3）确定Pum 1和 Pum 2与其他蛋白质相互作用以实现其对ESCs中靶mRNA的调节。的 这项研究如果能够实现，将大大提高我们对基因调控的认识。 干细胞的自我更新。此外，它应该揭示新的监管模式， Pum蛋白介导的转录后调节机制， 哺乳动物系统