美国Whitehead生物医学研究所Richard A. Young和麻省理工学院Arup K. Chakraborty课题组合作取得一项新成果。经过不懈努力，他们发现RNA介导的反馈机制控制转录冷凝物的产生。2020年12月16日，《细胞》在线发表了这项成果。

对RNA在转录调控中潜在作用的模型表明存在一种非平衡反馈控制机制，其中低表达的RNA促进由静电相互作用形成的冷凝物，而相对高表达的RNA则促进这些冷凝物的溶解。体外和体内实验的证据同时支持这一模型，其中在转录起始早期产生的RNA刺激凝结物形成，而在延伸过程中产生的大量RNA则促进凝结物的溶解。

研究人员假设存在一种转录反馈调控机制，从而起始转录的RNA会刺激转录但最终产生的RNA则阻止该过程。

据介绍，对生理过程的调节通常包含启动和终止这些过程，并且调控这些过程的机制通常涉及反馈调控。转录调控是基本的生理过程，其中大部分研究集中在转录起始过程，但对阻止该过程的机制了解甚少。

附：英文原文

Title: RNA-Mediated Feedback Control of Transcriptional Condensates

Author: Jonathan E. Henninger, Ozgur Oksuz, Krishna Shrinivas, Ido Sagi, Gary LeRoy, Ming M. Zheng, J. Owen Andrews, Alicia V. Zamudio, Charalampos Lazaris, Nancy M. Hannett, Tong Ihn Lee, Phillip A. Sharp, Ibrahim I. Cissé, Arup K. Chakraborty, Richard A. Young

Issue&Volume: 2020-12-16

Abstract: Regulation of biological processes typically incorporates mechanisms that initiateand terminate the process and, where understood, these mechanisms often involve feedbackcontrol. Regulation of transcription is a fundamental cellular process where the mechanismsinvolved in initiation have been studied extensively, but those involved in arrestingthe process are poorly understood. Modeling of the potential roles of RNA in transcriptionalcontrol suggested a non-equilibrium feedback control mechanism where low levels ofRNA promote condensates formed by electrostatic interactions whereas relatively highlevels promote dissolution of these condensates. Evidence from in vitro and in vivo experiments support a model where RNAs produced during early steps in transcriptioninitiation stimulate condensate formation, whereas the burst of RNAs produced duringelongation stimulate condensate dissolution. We propose that transcriptional regulationincorporates a feedback mechanism whereby transcribed RNAs initially stimulate butthen ultimately arrest the process.

DOI: 10.1016/j.cell.2020.11.030

Source: https://www.cell.com/cell/fulltext/S0092-8674(20)31567-1