Regulation of rRNA transcription in mammalian tissues

哺乳动物组织中 rRNA 转录的调控

• 批准号: 10459512
• 负责人: Vikram R. Paralkar
• 金额: $ 40.58万
• 依托单位: UNIVERSITY OF PENNSYLVANIA
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-21 至 2025-07-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10459512
• 关键词: Binding; Biogenesis; Biological Models; Biology; Cells; Chromatin; Complex; Consumption; DNA Binding; Development; Disease; Epigenetic Process; Eukaryota; Functional disorder; Genetic Transcription; Goals; Health; Homeostasis; Human; In Vitro; Knowledge; Malignant Neoplasms; Mammals; Molecular Machines; Mus; Mutation; Normal Cell; Normal tissue morphology; Organ; Organism; Process; Production; Proteins; Proteomics; RNA; Regulation; Reporting; Ribosomal DNA; Ribosomal RNA; Ribosomes; Role; Tissues; Work; cell type; genetic regulatory protein; in vivo; mouse model; novel; transcription factor

Abstract / Project Summary Ribosomal RNA (rRNA) comprises 90% of cellular RNA, and ribosome biogenesis is one of the most energy-consuming processes in the cell. The core rRNA transcriptional machinery is evolutionarily ancient and highly conserved from unicellular eukaryotes to mammals, but the bodies of higher organisms have different ribosome production rates in different cell types, responsive to unique tissue-specific demands. Mutations in ribosome biogenesis proteins cause cell-type-specific “ribosomopathies” in humans, manifested by developmental abnormalities, specific organ dysfunctions, or cancers. However, there is little understanding of the transcriptional and epigenetic factors that differentially regulate ribosome biogenesis across normal cells types in intact organisms. Specifically, no one has characterized the protein composition of nucleoli, or the components of rRNA transcription complexes, in any primary mammalian tissue. This represents a key knowledge gap in our understanding of eukaryotic biology. Using quantitative proteomics and transcription factor (TF) mapping studies in a mouse model system, we have identified nucleolar localization and abundant, specific binding to ribosomal DNA (rDNA) of several cell-type-specific TFs (Pu.1, Irf8, Etv6) that are known to be critical for normal development and survival, but whose roles in ribosome biogenesis have never been reported. We propose in this application a combination of unbiased as well as focused approaches to identify and dissect the roles of cell-type-specific rRNA regulators in tissue homeostasis. We will pursue this goal through the following projects: PROJECT 1: DISCOVERY: We will use nucleolar and rDNA-chromatin proteomics in defined primary mouse cell types to identify proteins with cell-type-specific nucleolar localization and rDNA binding. The goal of this project is to identify novel regulators of differential rRNA transcription in intact tissues. PROJECT 2: MECHANISM: We will use ​in vitro and ​in vivo degron and chromatin tethering approaches to dissect the direct roles of rDNA-binding cell-type-specific TFs (Pu.1, Irf8, Etv6, others) in the regulation of rDNA chromatin, rRNA transcription, and tissue homeostasis. The goal of this project is to understand how TF-rDNA binding regulates normal tissue biology. The long-term goal of this work is to gain a detailed understanding of how the ancient process of ribosome biogenesis has evolved to meet diverse tissue needs in complex organisms, and how disruption of this regulation can derange tissue homeostasis and cause disease.

摘要 /项目摘要 核糖体RNA（rRNA）占细胞RNA的90％，核糖体生物发生是最多一种 细胞中的能量耗尽过程。核心rRNA转录机械在进化上是古老的， 高度从单细胞真核生物到哺乳动物的高度保守，但是较高生物体的身体具有不同 不同细胞类型的核糖体生产速率，响应于独特的组织特异性需求。突变 核糖体生物发生蛋白在人类中引起细胞型特异性“核糖体病”，表现为 发育异常，特定器官功能障碍或癌症。但是，对 转录和表观遗传因子对正常细胞的核糖体生物发生有所不同 完整生物的类型。具体而言，没有人表征核仁的蛋白质组成，或 rRNA转录复合物的成分，在任何原发性哺乳动物组织中。这代表关键 我们对真核生物学的理解中的知识差距。 使用在小鼠模型系统中使用定量蛋白质组学和转录因子（TF）映射研究，我们 已经鉴定出核定位置并具有丰富的特异性结合与几个的核糖体DNA（rDNA） 细胞型特异性TF（PU.1，IRF8，ETV6），已知对于正常发育和生存至关重要，但是 从未报道过在核糖体生物发生中的作用。我们在此应用中建议 公正的和集中的方法，以识别和剖析细胞类型特异性rRNA调节剂的作用 在组织稳态中。我们将通过以下项目实现这一目标： 项目1：发现：我们将在定义的主要小鼠中使用核仁和rDNA-染色质蛋白质组学 细胞类型鉴定具有细胞类型特异性核定位和rDNA结合的蛋白质。目标的目标 项目是确定完整组织中差异rRNA转录的新调节剂。 项目2：机制：我们将在体外和体内脱脂和染色质链接方法 剖析rDNA结合细胞型特异性TF（PU.1，IRF8，ETV6，其他）在调节中的直接作用 rDNA染色质，rRNA转录和组织稳态。该项目的目的是了解如何 TF-RDNA结合调节正常组织生物学。 这项工作的长期目标是详细了解核糖体的古老过程 生物发生已经发展为满足复杂生物的潜水组织需求，以及如何破坏 调节可以发展组织稳态并引起疾病。