CAREER: Formation and Regulation of Chromatin-Associated Condensates

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助。细胞包含膜封闭的隔间，以组织生化反应。细胞还产生无膜隔室，称为生物分子凝聚物，以浓缩蛋白质和RNA。一些缩合物在特定位置形成，包括在细胞结构如染色体DNA上。然而，凝析液成核，生长，成分和流动性，这是必不可少的冷凝功能，网站特定的调节，仍然在很大程度上是未知的。利用一种基于光敏化学物质的新型化学光遗传学工具来操纵活细胞中的缩合物，该项目将揭示染色体DNA上蛋白质和RNA缩合物形成和调控的一般原理。该项目将通过在卡内基梅隆大学学术云实验室（一个学生可以从门户网站访问的最先进的科学实验室）与学生进行实验，让服务不足的高中生参与研究。此外，建立的研讨会将提供给其他教育工作者和学生与互联网接入，使更多的学生可以学习科学做科学。美国救援计划的资金用于支持这位早期职业研究者在其职业生涯的关键阶段。液-液相分离涉及许多染色质相关缩合物的形成，包括核仁，转录枢纽和DNA修复焦点。然而，我们的理解相分离过程中，调节冷凝物的性质，和相关的相分离的染色质功能的许多染色质相关的冷凝物仍然是有限的。该项目将结合联合收割机在活细胞中的化学光遗传学操作与生物物理定量和生化分析，以确定必要和充分的条件，蛋白质和RNA相分离染色质在核环境中，揭示如何核环境和主动信号控制冷凝物的生长，并剖析冷凝物的化学和材料特性如何产生的分子相互作用。该项目的结果将有助于确定蛋白质和RNA相分离是否以及如何有助于染色质功能。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Cells contain membrane-enclosed compartments to organize biochemical reactions. Cells also create membrane-less compartments, referred to as biomolecular condensates, to concentrate proteins and RNAs. Some condensates are formed at specific locations, including on cellular structures such as chromosomal DNA. However, site-specific regulation of condensate nucleation, growth, composition, and fluidity, which are essential for condensate functions, remain largely unknown. Using a novel chemoptogenetic tool based on light-sensitive chemicals to manipulate condensates in live cells, this project will uncover the general principles underpinning the formation and regulation of protein and RNA condensates on chromosomal DNA. This project will engage underserved high school students in the research by doing experiments with students in the Carnegie Mellon University Academic Cloud Lab, a state-of-the-art science laboratory that students can access from a web portal. In addition, the established curriculums will be available for other educators and students with internet access so more students can learn science by doing science. American Rescue Plan funding is used to support this early career investigator at a critical stage in his career.Liquid-liquid phase separation is implicated in the formation of many chromatin-associated condensates, including nucleoli, transcription hubs, and DNA repair foci. However, our understanding of the phase separation process, the regulation of condensate properties, and the relevance of phase separation in chromatin functions of many chromatin-associated condensates are still limited. This project will combine chemoptogenetic manipulation in live cells with biophysical quantification and biochemical assays to determine the necessary and sufficient conditions for protein and RNA phase separation on chromatin in the nuclear milieu, reveal how the nuclear environment and active signaling control condensate growth, and dissect how condensate chemical and material properties arise from molecular interactions. Results from this project will help determine whether and how protein and RNA phase separation contribute to chromatin functions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.