Function and regulation of the ETS transcriptional repressor Tel-1/Yan

描述(申请人提供)：这项工作的长期目标是阐明如何转录！在保守的信号网络下游运行的电路调节特定背景下的发育反应。因为对基因表达的精确调控是所有生物过程的基础，即使是轻微的失衡也可能导致严重的缺陷和疾病。我们的方法是利用遗传上易驯化的果蝇系统来发现新的基因调控策略，在体内从分子机制的细节水平上剖析它们，然后确认它们的保守性和与哺乳动物系统的相关性。这个建议的目的是研究一个保守的ETS家族转录抑制因子在体内的功能和调控，在果蝇中被称为Yen，在人类中被称为Tel1。该提案描述了一种结合体内遗传、分子、生化和基因组分析的多方面方法，以解决由Tel1/yan的SAM结构域介导的同型和异型相互作用允许与染色质的复杂关联的假说，而染色质是发育基因调控所必需的。其具体目的是检验Yen在体内作为转录抑制因子所必需的自我结合能力的假说，研究受调控的Yen聚合使其能够扩散到标准的高亲和力结合位点两侧的染色质中的机制，并探索这些调控策略相对于人类Tel1的保守性。这些实验的结果将定义一种转录抑制的新范式，在这种范式中，基因特异性转录调控因子的动态聚合可以调节下游靶基因的表达，以响应不断变化的信号条件。 由于我们正在研究的信号分子在哺乳动物中具有保守的功能，而且Tel1是白血病相关染色体重排的常见目标，我们的发现将直接适用于了解人类的发育和疾病。鉴于Tel1的自我关联能力被认为是几种常见白血病恶变的驱动力，这些研究产生的机制发现将为未来开发新的治疗措施来治疗Tell相关癌症提供重要基础。

DESCRIPTION (provided by applicant): The long-term objectives of this work are to elucidate how transcriptiona! circuitries operating downstream of conserved signaling networks mediate context-specific developmental responses. Because precisely orchestrated regulation of gene expression is fundamental to all biological processes, even slight imbalances can lead to serious defects and diseases. Our approach is to exploit the genetically tractable Drosophila system to uncover novel strategies of gene regulation, to dissect them in vivo at a molecular mechanistic level of detail, and then to confirm their conservation and relevance to mammalian systems. The goal of this proposal is to investigate the in vivo function and regulation of a conserved ETS family transcriptional repressor, referred to as Yan in Drosophila and Tel1 in humans. The proposal describes a multifaceted approach combining in vivo genetic, molecular, biochemical and genomic assays to address the hypothesis that homo- and heterotypic interactions mediated by the SAM domain of Tel1/Yan permit a complex association with chromatin that is essential for developmental gene regulation. The specific aims are to test the hypothesis that the ability of Yan to self-associate is required for its function as a transcriptional repressor in vivo, to investigate the mechanisms whereby regulated Yan polymerization allows it to spread into chromatin flanking a canonical high affinity binding site, and to explore the conservation of these regulatory strategies with respect to human Tel1. The results of these experiments will define a novel paradigm in transcriptional repression, in which dynamic polymerization of a gene specific transcriptional regulator can modulate expression of downstream target genes in response to changing signaling conditions. Because the signaling molecules we are studying have conserved functions in mammals, and because Tel1 is a frequent target of leukemia-associated chromosomal rearrangements, our findings will be directly applicable to understanding human development and disease. Given that the ability of Tel1 to self-associate is thought to provide a driving force toward malignant transformation in several common leukemias, the mechanistic discoveries emanating from these studies will provide an important foundation for developing novel therapeutic interventions to treat Tell-associated cancers in the future.