title: Regulatory interplay of Cockayne syndrome B ATPase and stress-response gene ATF3 following genotoxic stress.
abstract: Cockayne syndrome type B ATPase (CSB) belongs to the SwItch/Sucrose nonfermentable family. Its mutations are linked to Cockayne syndrome phenotypes and classically are thought to be caused by defects in transcription-coupled repair, a subtype of DNA repair. Here we show that after UV-C irradiation, immediate early genes such as activating transcription factor 3 (ATF3) are overexpressed. Although the ATF3 target genes, including dihydrofolate reductase (DHFR), were unable to recover RNA synthesis in CSB-deficient cells, transcription was restored rapidly in normal cells. There the synthesis of DHFR mRNA restarts on the arrival of RNA polymerase II and CSB and the subsequent release of ATF3 from its cAMP response element/ATF target site. In CSB-deficient cells ATF3 remains bound to the promoter, thereby preventing the arrival of polymerase II and the restart of transcription. Silencing of ATF3, as well as stable introduction of wild-type CSB, restores RNA synthesis in UV-irradiated CSB cells, suggesting that, in addition to its role in DNA repair, CSB activity likely is involved in the reversal of inhibitory properties on a gene-promoter region. We present strong experimental data supporting our view that the transcriptional defects observed in UV-irradiated CSB cells are largely the result of a permanent transcriptional repression of a certain set of genes in addition to some defect in DNA repair.
authors.affiliation: Department of Functional Genomics and Cancer Biology, Centre National de la Recherche Scientifique/Institut National de la Santé et de la Recherche Médicale, Laboratory of Medical Genetics, University of Strasbourg, 67404 Illkirch Cedex, France.
authors.forename: Ulrik
authors.initials: U
authors.lastname: Kristensen
authors.forename: Alexey
authors.initials: A
authors.lastname: Epanchintsev
authors.forename: Marc-Alexander
authors.initials: MA
authors.lastname: Rauschendorf
authors.forename: Vincent
authors.initials: V
authors.lastname: Laugel
authors.forename: Tinna
authors.initials: T
authors.lastname: Stevnsner
authors.forename: Vilhelm A
authors.initials: VA
authors.lastname: Bohr
authors.forename: Frédéric
authors.initials: F
authors.lastname: Coin
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Egly
mesh_terms: D051700:Activating Transcription Factor 3 / Q000235:genetics* / Q000378:metabolism; D002461:Cell Line, Transformed; D003057:Cockayne Syndrome / Q000235:genetics* / Q000378:metabolism; D004265:DNA Helicases / Q000235:genetics* / Q000378:metabolism; D004257:DNA Polymerase II / Q000235:genetics / Q000378:metabolism; D004260:DNA Repair / Q000235:genetics*; D045643:DNA Repair Enzymes / Q000235:genetics* / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000528:radiation effects; D015870:Gene Expression / Q000502:physiology / Q000528:radiation effects; D006801:Humans; D000075223:Poly-ADP-Ribose Binding Proteins; D061251:Primary Cell Culture; D034741:RNA, Small Interfering / Q000235:genetics; D013312:Stress, Physiological / Q000235:genetics*; D013762:Tetrahydrofolate Dehydrogenase / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000502:physiology / Q000528:radiation effects; D014466:Ultraviolet Rays / Q000009:adverse effects
chemical_list: C490449:ATF3 protein, human; D051700:Activating Transcription Factor 3; D000075223:Poly-ADP-Ribose Binding Proteins; D034741:RNA, Small Interfering; D013762:Tetrahydrofolate Dehydrogenase; D004257:DNA Polymerase II; D004265:DNA Helicases; C078673:ERCC6 protein, human; D045643:DNA Repair Enzymes