Regulatory Precision in Stress Responsive Transcriptional Networks

项目总结 许多细胞挑战--化学的、新陈代谢的和物理的--产生活性氧物种(ROS)， 它们有可能破坏包括蛋白质、脂类和核酸在内的大分子。成员： CnC转录因子家族，包括NRF2，调节抗氧化剂基因的表达和 减轻ROS介导的损害。这些相反的氧化剂和抗氧化剂的力量必须精确地平衡： 过少的NRF2和过多的ROS会导致细胞损伤和突变，而过多的NRF2会给细胞带来 危险的扩散优势。为了充分理解NRF2激活的机制含义，我们 需要全面了解其监管网络，但令人惊讶的是，人们对 NRF2的S调节活性以及它如何与其他应激反应转录因子结合。我们会 使用假设驱动的基因组学和重点生物验证实验的组合来提供 对NRF2监管网络的系统级和机械性洞察及其后果 激活。重要的是，这项工作还将解决有关转录的一般原则的问题。 调控的精确度，包括：(1)转录因子DNA的结合特性和组合 转录因子相互作用的整合，以驱动分级和开关样的基因表达，(2)动态 以及人类细胞中快速转录重编程的细胞类型特异性，(3)顺式基因的变异如何- 调节性DNA在功能上与疾病风险有关，以及(4)细胞自主和非自主的机制 自主监管网络传播。这些都是与所有转录监管机构相关的问题，所以 在NRF2介导的基因调控背景下获得的知识也将延伸到额外的转录 因素族。

PROJECT SUMMARY Many cellular challenges – chemical, metabolic, and physical – generate reactive oxygen species (ROS), which have the potential to damage macromolecules including proteins, lipids, and nucleic acids. Members of the Cap-n-Collar (CNC) transcription factor family, including NRF2, regulate antioxidant gene expression and mitigate ROS-mediated damage. These opposing oxidant and antioxidant forces must be precisely balanced: too little NRF2 and excess ROS cause cell damage and mutation, whereas too much NRF2 gives cells a dangerous proliferative advantage. To fully understand the mechanistic implications of NRF2 activation we need a comprehensive view of its regulatory network, yet surprisingly little is known about the global reach of NRF2's regulatory activity and how it integrates with additional stress-responsive transcription factors. We will use a combination of hypothesis-driven genomics and focused biological validation experiments to provide both systems level and mechanistic insights into the NRF2 regulatory network and consequences of its activation. Importantly, this work will also address issues regarding the general principles of transcriptional regulatory precision, including: (1) how transcription factor DNA binding properties and combinatorial transcription factor interactions integrate to drive graded versus switch-like gene expression, (2) the dynamics and cell-type specificity of rapid transcriptional reprogramming in human cells, (3) how variation in cis- regulatory DNA is functionally linked to disease risk, and (4) the mechanisms of cell autonomous and non- autonomous regulatory network propagation. These are relevant issues for all transcriptional regulators, so the knowledge gained in the context of NRF2-mediated gene regulation will also extend to additional transcription factor families.