Coin F, Frit P, Viollet B, Salles B, Egly J M
Institut de Génétique et de Biologie Moléculaire et Cellulaire, CNRS/INSERM/ULP, F-67404 Illkirch Cedex, Université Louis Pasteur, Strasbourg, France.
Mol Cell Biol. 1998 Jul;18(7):3907-14. doi: 10.1128/MCB.18.7.3907.
DNA damage recognition by basal transcription factors follows different mechanisms. Using transcription-competition, nitrocellulose filter binding, and DNase I footprinting assays, we show that, although the general transcription factor TFIIH is able to target any kind of lesion which can be repaired by the nucleotide excision repair pathway, TATA binding protein (TBP)-TFIID is more selective in damage recognition. Only genotoxic agents which are able to induce kinked DNA structures similar to the one for the TATA box in its TBP complex are recognized. Indeed, DNase I footprinting patterns reveal that TBP protects equally 4 nucleotides upstream and 6 nucleotides downstream from the A-T (at position -29 of the noncoding strand) of the adenovirus major late promoter and from the G-G of a cisplatin-induced 1,2-d(GpG) cross-link. Together, our results may partially explain differences in transcription inhibition rates following DNA damage.
基础转录因子对DNA损伤的识别遵循不同机制。通过转录竞争、硝酸纤维素滤膜结合和DNase I足迹分析,我们发现,尽管通用转录因子TFIIH能够靶向任何可通过核苷酸切除修复途径修复的损伤类型,但TATA结合蛋白(TBP)-TFIID在损伤识别上更具选择性。只有那些能够诱导类似于其TBP复合物中TATA盒的扭结DNA结构的基因毒性剂才能被识别。事实上,DNase I足迹模式显示,TBP对腺病毒主要晚期启动子非编码链-29位的A-T(以及顺铂诱导的1,2-d(GpG)交联的G-G)上游4个核苷酸和下游6个核苷酸提供同等程度的保护。总之,我们的结果可能部分解释了DNA损伤后转录抑制率的差异。