RNA polymerase II bypass of oxidative DNA damage is regulated by transcription elongation factors.
Oxidative lesions represent the most abundant DNA lesions within the cell. In the present study, we investigated the impact of the oxidative lesions 8-oxoguanine, thymine glycol and 5-hydroxyuracil on RNA polymerase II (RNA pol II) transcription using a well-defined in vitro transcription system. We found that in a purified, reconstituted transcription system, these lesions block elongation by RNA pol II to different extents, depending on the type of lesion. Suggesting the presence of a bypass activity, the block to elongation is alleviated when transcription is carried out in HeLa cell nuclear extracts. By purifying this activity, we discovered that TFIIF could promote elongation through a thymine glycol lesion. The elongation factors Elongin and CSB, but not TFIIS, can also stimulate bypass of thymine glycol lesions, whereas Elongin, CSB and TFIIS can all enhance bypass of an 8-oxoguanine lesion. By increasing the efficiency with which RNA pol II reads through oxidative lesions, elongation factors can contribute to transcriptional mutagenesis, an activity that could have implications for the generation or progression of human diseases.
Charlet-Berguerand
Nicolas
N
Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch Cedex, CU Strasbourg, France.
Feuerhahn
Sascha
S
Kong
Stephanie E
SE
Ziserman
Howard
H
Conaway
Joan W
JW
Conaway
Ronald
R
Egly
Jean Marc
JM
D004249:DNA Damage; D004265:DNA Helicases / Q000302:isolation & purification / Q000502:physiology; D004260:DNA Repair / Q000235:genetics*; D045643:DNA Repair Enzymes / Q000302:isolation & purification / Q000502:physiology; D000075065:Elongin; D006147:Guanine / Q000031:analogs & derivatives / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D018384:Oxidative Stress; D000075223:Poly-ADP-Ribose Binding Proteins; D012319:RNA Polymerase II / Q000037:antagonists & inhibitors*; D013941:Thymine / Q000031:analogs & derivatives / Q000494:pharmacology; D014157:Transcription Factors / Q000302:isolation & purification / Q000502:physiology; D019473:Transcription Factors, TFII / Q000302:isolation & purification / Q000502:physiology; D014158:Transcription, Genetic / Q000187:drug effects; D035602:Transcriptional Elongation Factors / Q000302:isolation & purification / Q000502:physiology*; D014498:Uracil / Q000031:analogs & derivatives / Q000494:pharmacology
D000075065:Elongin; D000075223:Poly-ADP-Ribose Binding Proteins; D014157:Transcription Factors; D019473:Transcription Factors, TFII; D035602:Transcriptional Elongation Factors; C018648:transcription factor S-II; C029389:thymine glycol; C045975:5-hydroxyuracil; C024829:8-hydroxyguanine; D014498:Uracil; D006147:Guanine; D012319:RNA Polymerase II; D004265:DNA Helicases; C078673:ERCC6 protein, human; C056604:transcription factor TFIIF; D045643:DNA Repair Enzymes; D013941:Thymine