The Role of pRB and Co-repressors in Transcriptional Regulation

pRB 和辅阻遏物在转录调控中的作用

基本信息

批准号：
8761281
负责人：
Brian D Dynlacht
金额：
$ 3.39万
依托单位：
NEW YORK UNIVERSITY SCHOOL OF MEDICINE
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-11-29 至 2014-09-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8761281
关键词：
Ablation Animal Model Apoptosis Binding Biochemical Cell Cycle Cell Cycle Arrest Cell Cycle Progression Cells Chromatin Chromatin Remodeling Factor Complex Coupled DNA E2F transcription factors Enzymes Exhibits Family Funding G1 Phase Gene Expression Gene Expression Regulation Gene Mutation Gene Targeting Genes Genetic Transcription Growth Health Histone Deacetylase In Vitro Individual Knockout Mice Lead Light Maintenance Mammalian Cell Muscle Muscle Cells Muscle Fibers Normal Cell Nucleosomes Phase Transition Phenotype Physiological Play Population Positioning Attribute Proliferating Protein Isoforms Proteins RNA Interference Recruitment Activity Regulation Repression Repressor Proteins Retinoblastoma Retinoblastoma Protein Role Specificity Transcriptional Regulation Tumor Suppressor Proteins base cdc Genes cell growth chromatin modification chromatin remodeling gene repression genome-wide histone methyltransferase histone modification in vivo p107 protein prevent promoter tumor tumorigenesis

项目摘要

DESCRIPTION (provided by applicant): Cellular differentiation is tightly coordinated with, and dependent upon, permanent cell cycle exit. The tumor suppressor pRB prevents tumorigenesis by virtue of its ability to suppress proliferation. It is clear that the pRB tumor family, which is comprised of pRB and the related proteins, p107 and p130 (also known as pocket proteins), is recruited to promoters through the E2F transcription factor. Once recruited, pocket proteins coordinate changes in gene expression with cell cycle progression and cell cycle exit, during transient growth arrest (quiescence) and permanent growth arrest that occurs upon cellular differentiation. Pocket proteins play a role in recruiting a cadre of co-repressors, such as Sin3-HDAC and histone methyltransferases, that modify chromatin and silence gene expression. Yet the mechanisms underlying the pRB-dependent changes in gene expression are not well understood. It is important to unravel these mechanisms, since they are likely to shed light on transcriptional controls associated with normal cell growth and tumor suppressive mechanisms. It is also unclear what transcriptional controls distinguish cells progressing through the M/G1 phase transition from those observed in cells re-emerging from growth arrest (the G0/G1 phase transition) and how differences in factor recruitment and chromatin modifications dictate transient growth arrest versus permanent cell cycle exit. We have found that pRB and the Sin3 co-repressor play a role in both settings. In this proposal, we seek to build upon results of the previous funding period and explore answers to these fundamental issues in the following Aims: (1) We will examine the role of E2F, pocket proteins, and Sin3 isoforms in factor recruitment, chromatin modification, and nucleosome remodeling during permanent cell cycle exit in muscle cells. (2) We will determine whether Sin3A and Sin3B isoforms can specifically regulate target gene transcription and purify endogenous complexes. (3) We will investigate the phenotype of Sin3 conditional knock-outs and attempt to unravel a role for Sin3 isoforms in maintaining cell cycle arrest in an animal model.

描述（由申请人提供）：细胞分化与永久细胞周期退出紧密协调并依赖于永久细胞周期退出。肿瘤抑制因子 pRB 凭借其抑制增殖的能力来防止肿瘤发生。很明显，pRB 肿瘤家族由 pRB 和相关蛋白 p107 和 p130（也称为口袋蛋白）组成，通过 E2F 转录因子被招募至启动子。一旦被招募，口袋蛋白就会在细胞分化时发生的短暂生长停滞（静止）和永久生长停滞期间协调基因表达与细胞周期进展和细胞周期退出的变化。口袋蛋白在招募一系列共抑制因子（例如 Sin3-HDAC 和组蛋白甲基转移酶）方面发挥着重要作用，这些共抑制因子可以修饰染色质并沉默基因表达。然而 pRB 依赖性基因表达变化的机制尚不清楚。解开这些机制很重要，因为它们很可能揭示与正常细胞生长和肿瘤抑制机制相关的转录控制。目前还不清楚哪些转录控制可以区分正在经历 M/G1 相变的细胞与从生长停滞（G0/G1 相变）重新出现的细胞中观察到的细胞，以及因子招募和染色质修饰的差异如何决定短暂的生长停滞与永久细胞周期退出。我们发现 pRB 和 Sin3 辅阻遏蛋白在这两种情况下都发挥作用。在本提案中，我们寻求以上一资助期的结果为基础，并在以下目标中探索这些基本问题的答案：（1）我们将研究 E2F、口袋蛋白和 Sin3 同工型在因子招募、染色质修饰中的作用，并且在肌肉细胞中存在永久细胞周期期间的核小体重塑。 (2)我们将确定Sin3A和Sin3B亚型是否可以特异性调控靶基因转录并纯化内源复合物。 (3) 我们将研究 Sin3 条件敲除的表型，并尝试阐明 Sin3 同工型在动物模型中维持细胞周期停滞的作用。