TAFopathies Result from Derangements in Transcriptional Control of Metabolism

项目摘要 智力障碍是一种致残性神经发育障碍，影响2%-3%的总人口。 通常情况下，这些智力残疾伴随着额外的发育异常。这些 智力残疾的症状形式往往有遗传基础。最近的研究发现了一种 具有TATA结合蛋白关键成分致病变异的智力残疾患者亚群 相关因素(TAFs)。这些患者还患有头面部缺陷和先天性心脏病。这 综合征被称为TAF病，包括TATA结合蛋白(TBP)，TAF1， TAF2和TAF6。通过正向基因筛查，我们在TAF5中恢复了一个致命的无义突变。 突变胚胎在出生后96小时出现头面部发育不良、脑室发育不良和心力衰竭。 受精。CRISPR/Cas9介导的基因编辑表明，该表型在TAF1 KO中重现 和TAF5KO胚胎。TAF5KO表现出显著的代谢功能障碍，可能先于解剖 受精后96小时观察到的缺陷。综上所述，这些发现支持了TAFs在 协调胚胎发育过程中代谢程序的转录激活。TAFs组成了 通用转录因子TFIID，它招募RNA聚合酶II在 抄写。研究表明，单个TAFs不是一般转录所必需的。其他 研究已经确定了TAF1的功能结构域，它通过与TBP和TBP的相互作用激活转录 足以将RNA聚合酶II招募到转录位点的增强子元件。与 我们的数据显示代谢功能障碍，我们假设TAFs通过链接调节代谢程序 通过TFIID组装代谢基因的增强子和启动子。我们目前的努力集中在 完成我们的TAF1 KO和TAF5 KO相对于颅面的表型特征-和 神经发育。我们计划使用创新和尖端技术，包括x射线显微镜，RNA- 范围原位杂交、线粒体呼吸检测、CHIP-SEQ和Hi-C以实现这一目标。数据 所获得的结果将有助于阐明TAF病的基本发病机制。这些发现也将表明 一般转录因子在胚胎发育过程中调节代谢编程的次级功能。 。

Project Summary Intellectual disability is a disabling neurodevelopmental disorder that affects 2-3% of the general population. Often times, these intellectual disabilities are accompanied by additional developmental abnormalities. These syndromic forms of intellectual disability frequently have a genetic basis. Recent studies have identified a subset of intellectual disability patients with pathogenic variants in key components of the TATA-binding protein associated factors (TAFs). These patients also have craniofacial defects and congenital heart disease. This syndrome has been termed as a TAFopathy and includes mutations in TATA binding protein (TBP), TAF1, TAF2, and TAF6. Through a forward genetic screen, we have recovered a lethal nonsense mutation in TAF5. Mutant embryos have craniofacial hypoplasia, ventricular hypoplasia, and heart failure at 96 hours post fertilization. CRISPR/Cas9 mediated gene editing revealed that this phenotype was recapitulated in TAF1 KO and TAF5 KO embryos. TAF5 KOs show significant metabolic dysfunction that may precede the anatomical defects observed at 96 hours post fertilization. Together, these findings support a regulatory role for TAFs in coordinating transcriptional activation of metabolic programming during embryogenesis. The TAFs form the general transcription factor TFIID, which recruits RNA Polymerase II to form the preinitation complex at sites of transcription. Studies have shown that individual TAFs are not necessary for general transcription. Other studies have identified functional domains of TAF1 that activate transcription through interactions with TBP and enhancer elements that are sufficient to recruit RNA Polymerase II to sites of transcription. In conjunction with our data showing metabolic dysfunction, we hypothesize that TAFs regulate metabolic programs by linking enhancers and promoters of metabolic genes through TFIID assembly. Our current efforts are focused towards completing our phenotypic characterization of TAF1 KOs and TAF5 KOs with respect to craniofacial- and neuro-development. We plan to use innovative and cutting-edge techniques, including x-ray microscopy, RNA- Scope in situ hybridization, mitochondrial respiration assays, ChIP-seq, and Hi-C to achieve this goal. The data obtained will help us elucidate basic disease mechanisms of TAFopathy. These findings would also indicate a secondary function for general transcription factors to regulate metabolic programming during embryogenesis. .