E2F7 & E2F8 in the control of transcription and cellular proliferation

E2F7

• 批准号: 7749926
• 负责人: GUSTAVO Walter LEONE
• 金额: $ 31.13万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-12-10 至 2012-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7749926
• 关键词: Ablation; Affinity Chromatography; Animals; Apoptosis; Binding; Biochemical; Biochemical Genetics; Biological; Cell Cycle; Cell Cycle Regulation; Cell Proliferation; Cells; Complex; Data; Defect; Development; Embryo; Family; Family member; Gene Expression; Gene Targeting; Generations; Genes; Genetic; Genetic Transcription; Homo; Individual; Laboratories; Macromolecular Complexes; Malignant Neoplasms; Methods; Multiprotein Complexes; Mus; Oncogenic; Pattern; Phenotype; Phosphotransferases; Play; Positioning Attribute; Protein Sequence Analysis; Proteins; Reagent; Recruitment Activity; Research; Role; Signal Pathway; Structure; System; Technology; Testing; Tissues; Transcription Repressor/Corepressor; Tumor Suppressor Proteins; Work; arm; base; combinatorial; in vivo; member; novel; overexpression; programs; promoter; protein complex; protein protein interaction; transcription factor

DESCRIPTION (provided by applicant): The E2F family of transcription factors is believed to play a critical role in the control of cellular proliferation. These factors are encoded by distinct genes and have both tumor suppressor and oncogenic functions (1-2). Our laboratory identified E2F7 and E2F8 as the final two members of this transcription factor family (5, 6). The preliminary data presented in this proposal highlight several unique features of these two E2Fs that place them in a subclass of their own. These salient features include their ability to form homodimers and heterodimers, to associate with a large cadre of transcriptional co-repressors, to silence gene expression, and to block cellular proliferation. While they lack a typical Rb-binding domain, E2F7 can specifically interact with Rb related proteins and can thus recruit E2F8 to Rb-containing complexes. As a result, the E2F7/8 arm of the E2F network remains under the control of the cycling dependent kinase (CDK) signaling pathway. The fact that E2F7 and E2F8 have an identical pattern of cell cycle dependent and tissue- specific expression, together with their ability to homo- and hetero-dimerize, raises the possibility that they may have both unique and shared functions in the animal. A multi-faceted effort in the laboratory has yielded key technical developments, including an affinity purification strategy to purify E2F7/8-associated proteins, promoter-array technologies to identify target genes, and gene targeting approaches to disrupt E2F7 and E2F8 in mice. These advances place our research group in a strong position to make significant advances towards a mechanistic understanding of how this important arm of the E2F family of factors controls the cell cycle and cell proliferation. The overarching hypothesis of this proposal is that E2F7 and E2F8 function as transcriptional repressors to negatively control cellular proliferation. Three specific aims utilizing biochemical, biophysical, global gene array, and genetic approaches will directly test this hypothesis: Specific Aim 1. To identify and characterize E2F7- and E2F8-associated macromolecular protein complexes. Specific Aim 2. To identify E2F7 and E2F8 transcriptional targets. Specific Aim 3. To determine the mechanism of E2F7 and E2F8 action in the control of transcription. This work will elucidate the individual and combinatorial contributions made by these two highly related family members towards the overall understanding of E2F transcriptional activity.

描述（由申请人提供）：E2F转录因子家族被认为在细胞增殖的控制中发挥着关键作用。这些因子由不同的基因编码，具有抑癌和致癌功能 (1-2)。我们的实验室确定 E2F7 和 E2F8 是该转录因子家族的最后两个成员 (5, 6)。该提案中提供的初步数据强调了这两个 E2F 的几个独特功能，这些功能将它们置于自己的子类中。这些显着特征包括它们形成同二聚体和异二聚体、与大量转录共阻遏物相关、沉默基因表达和阻止细胞增殖的能力。虽然它们缺乏典型的 Rb 结合结构域，但 E2F7 可以与 Rb 相关蛋白特异性相互作用，从而将 E2F8 募集到含 Rb 的复合物中。因此，E2F 网络的 E2F7/8 臂仍处于循环依赖性激酶 (CDK) 信号通路的控制之下。 E2F7和E2F8具有相同的细胞周期依赖性和组织特异性表达模式，以及它们同源和异源二聚化的能力，这一事实提出了它们在动物中可能具有独特和共享功能的可能性。实验室的多方面努力已经取得了关键的技术进展，包括纯化 E2F7/8 相关蛋白的亲和纯化策略、识别靶基因的启动子阵列技术，以及破坏小鼠 E2F7 和 E2F8 的基因靶向方法。这些进展使我们的研究小组处于有利地位，能够在机制理解 E2F 家族因子的这一重要分支如何控制细胞周期和细胞增殖方面取得重大进展。该提议的总体假设是 E2F7 和 E2F8 作为转录抑制因子来负向控制细胞增殖。利用生物化学、生物物理、全局基因阵列和遗传方法的三个具体目标将直接检验这一假设： 具体目标 1. 识别和表征 E2F7 和 E2F8 相关大分子蛋白质复合物。具体目标 2. 鉴定 E2F7 和 E2F8 转录靶标。具体目标3.确定E2F7和E2F8在转录控制中的作用机制。这项工作将阐明这两个高度相关的家族成员对 E2F 转录活性的整体理解所做出的个体和组合贡献。