Mammalian H3K4 Methylases, Chromosomal Translocations and Human Leukemia

哺乳动物 H3K4 甲基化酶、染色体易位和人类白血病

• 批准号: 8595296
• 负责人: Ali Shilatifard
• 金额: $ 34.76万
• 依托单位: STOWERS INSTITUTE FOR MEDICAL RESEARCH
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-03-09 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8595296
• 关键词: Address; Applications Grants; Biochemical; Biochemical Genetics; Biological; Cells; Chimera organism; Chromatin; Chromosomal Rearrangement; Chromosomal translocation; Complex; DNA Sequence Rearrangement; Detection; Development; Diagnosis; Elongation Factor; Embryo; Etiology; Family; Family member; Gene Expression Alteration; Gene Targeting; Genes; Genetic Screening; Goals; Hematologic Neoplasms; Histone H3; Homologous Gene; Human; Knowledge; Life; Lysine; MLL gene; Malignant Neoplasms; Mammalian Cell; Methylation; Methyltransferase; Modification; Molecular; Molecular Genetics; Pathogenesis; Phenotype; Play; Polymerase; Post-Translational Protein Processing; Property; Protein Family; Proteins; RNA Polymerase II; Research Personnel; Role; Site; Specificity; Therapeutic; Transcription Elongation; Yeasts; abstracting; base; cell growth; design; enzyme activity; leukemia; tool

Project Summary/Abstract Chromosomal rearrangements resulting in alteration of gene expression are a major cause of hematological malignancies. This grant application is focused on the characterization of the molecular functions and biochemical properties of the MLL family of proteins and its chimeras in the hope of advancing our understanding of the molecular mechanisms of rearrangement-based leukemia. Our studies during the past five years have considerably expanded our molecular understanding of the role of MLL1 and one of its translocation partners, the ELL protein. We and others have identified MLL, MLL-related proteins and their complexes as histone H3 lysine 4 (H3K4) methylases. Through our biochemical and genetic screens, we have also identified the molecular machinery required for the proper enzymatic activity of the H3K4 methylases. We have also demonstrated that the ELL protein, one of the MLL1 partners in leukemia, is a bona fide RNA polymerase II elongation factor regulating the transcriptional properties of the elongating form of RNA polymerase II. These studies have helped to create the paradigm that posttranslational modifications of chromatin by methylation and transcriptional elongation control participate in the etiology of leukemia. Building on these discoveries, the goals of this proposal are to characterize the gene targets of the mammalian H3K4 methylases and to understand the molecular mechanism of translocation-based leukemia via MLL-chimeras. These goals will be aggressively pursued via two specific aims. Specific Aim 1 is focused on identifying the gene targets of the six mammalian H3K4 methylases and to define how these methylases acquire their gene target specificity and understand the biological significance of H3K4 methylation at such sites. Specific Aim 2 is focused on the biochemical isolation of several of the MLL-translocation chimeras and on defining their molecular composition in the hope of identifying a molecular commonality among the chimeras, which may result in the pathogenesis of a leukemic phenotype. We will take advantage of a variety of biochemical, molecular and genetic tools to address the aims proposed in this application. The proposed studies should (i) have a fundamental impact on our understanding of how MLL translocations result in the pathogenesis of hematological malignancies; and (ii) be instrumental for our understanding of the diverse roles that the mammalian H3K4 methylase machinery plays during development and differentiation. The information provided by these studies have the potential of some day proving helpful to investigators attempting to design rational approaches for the treatment of certain human malignancies using target specific therapeutics.

项目摘要/摘要 导致基因表达改变的染色体重排是 血液学恶性肿瘤。该赠款应用集中在分子的表征上 MLL蛋白质及其嵌合体的功能和生化特性，以期 促进我们对基于重排的白血病的分子机制的理解。我们的 在过去五年中的研究大大扩展了我们对 MLL1及其转运伙伴之一ELL蛋白。我们和其他人已经确定了MLL， 与MLL相关的蛋白质及其复合物为组蛋白H3赖氨酸4（H3K4）甲基酶。通过我们的 生化和遗传筛选，我们还确定了该分子机制 H3K4甲基酶的适当酶活性。我们还证明了ELL蛋白， 白血病的MLL1合作伙伴之一是真正的RNA聚合酶II延伸因子调节因子 RNA聚合酶II的伸长形式的转录特性。这些研究有助于 创建以甲基化和转录的染色质翻译后修饰的范例 伸长控制参与白血病的病因。 在这些发现的基础上，该提案的目标是表征 哺乳动物H3K4甲基酶，并了解基于易位的分子机制 白血病通过MLL-Chimeras。这些目标将通过两个具体目标积极追求。具体的 AIM 1专注于识别六种哺乳动物H3K4甲基酶的基因靶标并定义 这些甲基酶如何获得其基因靶标特异性并理解的生物学意义 H3K4甲基化在此类部位。具体目标2集中于几个的生化隔离 MLL转换嵌合体并定义其分子组成，以期识别 嵌合体之间的分子共同点，这可能导致白血病的发病机理 表型。 我们将利用各种生化，分子和遗传工具来解决 本应用程序中提出的目的。拟议的研究应（i）对我们的基本影响 了解MLL易位如何导致血液学恶性肿瘤的发病机理；和 （ii）对我们对哺乳动物H3K4甲基化酶的多种作用的理解有助于 机械在开发和差异化过程中发挥作用。这些研究提供的信息 有可能有一天证明对试图设计理性方法的调查人员有帮助 使用目标特定治疗剂治疗某些人类恶性肿瘤。