美国哈佛医学院Johannes C. Walter和Lucas Farnung共同合作，近期取得重要工作进展。他们研究提出，STK19定位TFIIH进行无细胞转录偶联DNA修复。相关研究成果2024年11月14日在线发表于《细胞》杂志上。
据介绍，在转录偶联核苷酸切除修复（TC-NER）中，停滞的RNA聚合酶II（RNA Pol II）结合CSB和CRL4CSA，与UVSSA和ELOF1协同招募TFIIH。
为了探索TC-NER的机制，研究人员总结了这种体外反应。当含有位点特异性损伤的质粒在青蛙卵提取物中转录时，观察到依赖于CSB、CRL4CSA、UVSSA和ELOF1的无错误修复。修复还需要STK19，这是一种以前发现的与紫外线照射后转录恢复有关的因子。1.9Å冷冻电镜结构显示，STK19通过CSA和RNA Pol II的RPB1亚基结合TC-NER复合物。
此外，AlphaFold预测STK19与TFIIH的XPD亚基相互作用，破坏这一界面会损害无细胞修复。分子建模表明，STK19将TFIIH定位在RNA Pol II之前，用于病变验证。研究人员对无细胞TC-NER的分析表明，STK19将RNA Pol II停滞与下游修复事件相结合。
附：英文原文
Title: STK19 positions TFIIH for cell-free transcription-coupled DNA repair
Author: Tycho E.T. Mevissen, Maximilian Kümmecke, Ernst W. Schmid, Lucas Farnung, Johannes C. Walter
Issue&Volume: 2024-11-14
Abstract: In transcription-coupled nucleotide excision repair (TC-NER), stalled RNA polymerase II (RNA Pol II) binds CSB and CRL4CSA, which cooperate with UVSSA and ELOF1 to recruit TFIIH. To explore the mechanism of TC-NER, we recapitulated this reaction in vitro. When a plasmid containing a site-specific lesion is transcribed in frog egg extract, error-free repair is observed that depends on CSB, CRL4CSA, UVSSA, and ELOF1. Repair also requires STK19, a factor previously implicated in transcription recovery after UV exposure. A 1.9- cryo-electron microscopy structure shows that STK19 binds the TC-NER complex through CSA and the RPB1 subunit of RNA Pol II. Furthermore, AlphaFold predicts that STK19 interacts with the XPD subunit of TFIIH, and disrupting this interface impairs cell-free repair. Molecular modeling suggests that STK19 positions TFIIH ahead of RNA Pol II for lesion verification. Our analysis of cell-free TC-NER suggests that STK19 couples RNA Pol II stalling to downstream repair events.
DOI: 10.1016/j.cell.2024.10.020
Source: https://www.cell.com/cell/abstract/S0092-8674(24)01202-9