TRANSCRIPTIONAL REGULATION BY GEMININ

GEMININ 的转录调控

• 批准号: 7595037
• 负责人: Kristen L Kroll
• 金额: $ 28.88万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-01-01 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7595037
• 关键词: ATP phosphohydrolase; Affect; Area; Binding; Cancer Biology; Cell Lineage; Cells; Chromatin; Complex; Data; Development; Diagnostic; Disease; Embryo; Embryonic Development; Enhancers; Epigenetic Process; Event; Foundations; Future; Geminin; Gene Expression; Gene Targeting; Genetic Transcription; Health; Human; Inner Cell Mass; Knowledge; Laboratories; Logic; Malignant Neoplasms; Mediating; Methods; Modeling; Modification; Multipotent Stem Cells; Mus; Neuronal Differentiation; Neurons; Pattern; Phenotype; Polycomb; Proteins; Reagent; Recruitment Activity; Regulation; Regulator Genes; Repression; Role; Stem cells; Therapeutic; Time; Transactivation; Transcriptional Regulation; Work; Xenopus; aggressive therapy; base; blastomere structure; cell fate specification; chromatin modification; chromatin remodeling; embryonic stem cell; gene repression; genetic regulatory protein; human disease; in vivo; innovation; interest; loss of function; nerve stem cell; neurogenesis; novel; pluripotency; public health relevance; relating to nervous system; stem; stem cell population; therapy resistant; tool; transcription factor

DESCRIPTION (provided by applicant): Understanding regulatory mechanisms that maintain pluripotent embryonic cells and control differentiation has fundamental relevance to scientific areas central to human health and disease, including stem cell, developmental, and cancer biology. The novel Geminin (Gem) protein acts together with the SWI/SNF and Polycomb (PcG) chromatin regulatory complexes as key transcriptional regulators of cell lineage specification and differentiation in embryonic and embryonic stem (ES) cells. Dysregulation of Gem, SWI/SNF and PcG activities is also a pivotal aspect of multiple human malignancies. A major focus of my laboratory is to understand how this core transcriptional regulatory switch operates and to define approaches for manipulating it in both normal ES and progenitor cell contexts and in disease. Our preliminary results support a model where Gem maintains pluripotent and/or multipotent progenitor cells by direct transcriptional repression of cell lineage commitment and differentiation regulatory genes. We hypothesize that Gem does this: 1. by directly cooperating with PcG complexes to repress the expression of common target loci. In support of this, we recently defined Gem-repressed target genes, and found these overlapped strikingly with direct targets of PcG repression to block cell lineage commitment. 2. Gem also acts in neuronal progenitor cells to regulate differentiation timing. For this activity, we hypothesize that Gem antagonizes target gene transactivation by the coordinated activities of SWI/SNF and Neurogenin2 and NeuroD, neural bHLH transcription factors required for neuronal fate commitment and differentiation. Here, in Aim 1 we will use an innovative, high-throughput approach to identify enhancers that are bound and regulated by Neurogenin2 and NeuroD in their direct target genes, and negatively regulated by Gem. This will fill an existing gap in our knowledge by defining transcriptional regulatory mechanisms and networks through which Neurogenin2 and NeuroD perform essential roles in neurogenesis and will provide a necessary sequence context for analyzing Gem's role in this regulation. In Aims 2 and 3, we will analyze how Gem, SWI/SNF and PcG are recruited to and mechanistically control expression of Gem target genes and how disrupting functional interplay between these activities perturbs target gene transactivation at the chromatin level during neuronal differentiation. Together, these studies will elucidate mechanisms and logic of a core transcriptional regulatory switch required to maintain embryonic stem and progenitor cells and to regulate differentiation. Information and tools that we develop here will provide a foundation for diagnostic and therapeutic manipulations of this regulatory switch in both normal stem and progenitor cells and in disease contexts such as malignancy. PUBLIC HEALTH RELEVANCE: The proposed work will determine mechanisms of action of a central regulatory switch controlling gene expression in embryonic stem cells and dysregulated in many aggressive, therapy-resistant forms of cancer. Information and tools that we develop here will provide a critical foundation for manipulating this regulatory switch for both diagnostic and therapeutic purposes in normal stem cell contexts and in treating human malignancies.

描述（由申请人提供）：了解维持多能胚胎细胞和控制分化的调控机制与人类健康和疾病的核心科学领域（包括干细胞、发育和癌症生物学）具有根本相关性。新的Geminin（Gem）蛋白与SWI/SNF和Polycomb（PcG）染色质调节复合物一起作为胚胎和胚胎干（ES）细胞中细胞谱系特化和分化的关键转录调节因子起作用。Gem、SWI/SNF和PcG活性的失调也是多种人类恶性肿瘤的关键方面。我的实验室的一个主要重点是了解这个核心转录调控开关如何运作，并定义在正常ES和祖细胞环境和疾病中操纵它的方法。 我们的初步结果支持一种模型，其中Gem通过直接转录抑制细胞谱系定型和分化调控基因来维持多能和/或多能祖细胞。我们假设Gem是这样做的：1。通过直接与PcG复合物协同作用抑制共同靶位点的表达。为了支持这一点，我们最近定义了GEM抑制的靶基因，并发现这些与PcG抑制的直接靶基因惊人地重叠，以阻止细胞谱系定型。2. Gem还在神经元祖细胞中起作用以调节分化时间。对于这种活性，我们假设Gem通过SWI/SNF和Neurogenin 2和NeuroD的协调活性拮抗靶基因的反式激活，神经元命运承诺和分化所需的神经bHLH转录因子。 在这里，在目标1中，我们将使用一种创新的高通量方法来鉴定在其直接靶基因中由Neurogenin 2和NeuroD结合和调节的增强子，以及由Gem负调控的增强子。这将填补现有的空白，我们的知识，通过定义转录调控机制和网络，通过神经生成素2和NeuroD执行神经发生中的重要作用，并将提供必要的序列背景下分析宝石的作用，在这种调节。在目标2和3中，我们将分析Gem、SWI/SNF和PcG如何被募集并机械地控制Gem靶基因的表达，以及在神经元分化期间，这些活动之间的破坏性功能相互作用如何在染色质水平上扰乱靶基因的反式激活。总之，这些研究将阐明维持胚胎干细胞和祖细胞以及调节分化所需的核心转录调控开关的机制和逻辑。我们在这里开发的信息和工具将为正常干细胞和祖细胞以及恶性肿瘤等疾病背景下的这种调节开关的诊断和治疗操作提供基础。 公共卫生相关性：拟议的工作将确定控制胚胎干细胞中基因表达的中央调节开关的作用机制，以及许多侵袭性，耐药形式的癌症中的失调。我们在这里开发的信息和工具将为在正常干细胞背景下和治疗人类恶性肿瘤中操纵这种调节开关以用于诊断和治疗目的提供关键基础。