Role of the transcriptional intermediary factor TIF1g in vertebrate hematopoiesis

描述(申请人提供)：我的职业目标是领导一个独立的研究小组，研究控制造血细胞命运的染色质因子的性质和功能。我在表观遗传基因调控方面的研究背景，加上我在斑马鱼遗传学和造血学方面的开发专业知识，为我提供了进行拟议研究的知识。儿童医院和哈佛医学院血液科/肿瘤科的培训计划为在指导阶段完成培训提供了良好的环境。这将极大地促进我向独立的平稳过渡。 造血是由复杂的遗传程序控制的，涉及组织特异性转录因子和染色质重塑因子。了解造血调控机制对人类血液恶性肿瘤(如白血病)的病理生理学有重要意义。转录中介因子TIF1？是造血的关键因素，但其机制尚不清楚。通过使用斑马鱼TIF1的大规模基因抑制筛查？突变体，我鉴定了两个可以绕过TIF1要求的抑制子突变体？并恢复缺乏TIF1？的动物的血液。这些突变体的初步特征表明TIF1？在造血过程中调节转录延长和染色质重塑。这项建议中描述的研究旨在阐明TIF1？？调节这些过程的机制。AIM1将使用染色质免疫沉淀(CHIP)分析来彻底检查TIF1？缺陷细胞中RNA聚合酶II和相关的组蛋白标记物在血液基因上的分布。AIM2将利用现有的条件基因敲除小鼠来研究TIF1？和它的抑制子在哺乳动物的造血中。Aim3将重点深入刻画TIF1？以及使用遗传和生化方法的粘附素染色质重塑复合体。这些目标的完成将揭示在造血过程中转录因子、延伸因子和染色质重构体之间的相互作用。鉴于转录延长和染色质修饰参与了多种人类疾病，这些研究将促进我们对它们在这些疾病的发病机制和进展中所起作用的理解，并可能识别可用于开发新的靶向治疗策略的候选基因或途径。 公共卫生相关性：更深入地了解造血基因计划的调控将有助于改善白血病和贫血等血液病的治疗。通过研究造血基因调控的表观遗传学方面，我的研究将促进我们对控制血液形成的机制的理解，并可能发现新的调控因子，从而拓宽血液疾病的可能治疗靶点。

DESCRIPTION (provided by applicant): My career goal is to direct an independent research group studying the nature and function of chromatin factors that control hematopoietic cell fate. My research background in epigenetic gene regulation plus my developing expertise in zebrafish genetics and hematopoiesis provide me with the knowledge to perform the proposed research. The training program in the hematology/oncology division at Children's Hospital and Harvard Medical School provides an outstanding environment for the completion of training during the mentored phase. This will greatly facilitate my smooth transition to independence. Hematopoiesis is controlled by complicated genetic programs involving tissue-specific transcription factors and chromatin remodeling factors. Understanding the regulatory mechanism of hematopoiesis provides significant insight into the pathophysiology of human blood malignancies such as leukemia. The transcription intermediary factor TIF1? is a critical factor for hematopoiesis yet the mechanism is not well understood. Through a large-scale genetic suppressor screen using the zebrafish TIF1? mutant, I identified two suppressor mutants that can bypass the requirement of TIF1? and restore blood in TIF1?-deficient animals. Initial characterizations of these mutants suggest a fundamental role of TIF1? in regulating transcriptional elongation and chromatin remodeling during hematopoiesis. The research described in this proposal is designed to elucidate the mechanism by which TIF1??regulates these processes. Aim1 will use chromatin immunoprecipitation (ChIP) analyses to thoroughly examine the distribution of RNA polymerase II and associated histone markers on blood genes in TIF1?-deficient cells. Aim2 will use the available conditional knockout mice to investigate the function of TIF1? and its suppressors in mammalian hematopoiesis. Aim3 will focus on the in-depth characterization of the interaction between TIF1? and the cohesin chromatin remodeling complex using genetic and biochemical approaches. Completion of these aims will reveal the interplay among transcription factors, elongation factors and chromatin remodelers during hematopoiesis. Given the involvement of transcriptional elongation and chromatin modification in a variety of human disorders, these studies will advance our understanding of their roles in the pathogenesis and progression of these maladies and may also identify candidate genes or pathways that can be used for developing novel targeted treatment strategies. PUBLIC HEALTH RELEVANCE: Greater insight into the regulation of hematopoietic gene program will lead to improved treatment for hematologic disorders such as leukemia and anemia. By studying the epigenetic aspect of hematopoietic gene regulation, my research will advance our understanding of the mechanisms that controls blood formation and may identify novel regulators that will broaden possible therapeutic targets for blood diseases.