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。细胞含有膜封闭的区室来组织生化反应。细胞也产生无膜的隔间，被称为生物分子凝聚体，用来浓缩蛋白质和rna。一些凝析物在特定的位置形成，包括在细胞结构上，如染色体DNA上。然而，凝析油成核、生长、组成和流动性等对凝析油功能至关重要的部位特异性调节，在很大程度上仍然未知。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凝聚物，该项目将揭示染色体DNA上蛋白质和RNA凝聚物形成和调控的一般原理。该项目将通过在卡耐基梅隆大学学术云实验室（一个学生可以通过门户网站访问的最先进的科学实验室）与学生一起进行实验，吸引缺乏服务的高中生参与研究。此外，已建立的课程将提供给其他教育工作者和有互联网接入的学生，这样更多的学生可以通过做科学来学习科学。美国救援计划的资金用于支持这位早期职业调查员在他职业生涯的关键阶段。液-液相分离涉及许多染色质相关凝聚物的形成，包括核仁、转录中心和DNA修复病灶。然而，我们对许多染色质相关凝析物的相分离过程、凝析物性质的调节以及相分离在染色质功能中的相关性的理解仍然有限。本项目将结合活细胞的化学光遗传学操作与生物物理定量和生化分析，以确定核环境中染色质上蛋白质和RNA相分离的必要和充分条件，揭示核环境和活性信号如何控制凝析物生长，并剖析凝析物的化学和物质特性如何从分子相互作用中产生。这个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促进染色质功能。该奖项反映了美国国家科学基金会的法定使命，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.