title: det1-1-induced UV-C hyposensitivity through UVR3 and PHR1 photolyase gene over-expression.
abstract: Obligate photoautotrophs such as plants must capture energy from sunlight and are therefore exposed to the damaging collateral effects of ultraviolet (UV) irradiation, especially on DNA. Here we investigated the interconnection between light signaling and DNA repair, two concomitant pathways during photomorphogenesis, the developmental transition associated with the first light exposure. It is shown that combination of an enhanced sunscreen effect and photoreactivation confers a greater level of tolerance to damaging UV-C doses in the constitutive photomorphogenic de-etiolated1-1 (det1--1) Arabidopsis mutant. In darkness, expression of the PHR1 and UVR3 photolyase genes, responsible for photoreactivation, is maintained at a basal level through the positive action of HY5 and HYH photomorphogenesis-promoting transcription factors and the repressive effects of DET1 and COP1. Upon light exposure, HY5 and HYH activate PHR1 gene expression while the constitutively expressed nuclear-localized DET1 protein exerts a strong inhibitory effect. Altogether, the data presented indicate a dual role for DET1 in controlling expression of light-responsive and DNA repair genes, and describe more precisely the contribution of photomorphogenic regulators in the control of light-dependent DNA repair.
authors.affiliation: Environmental and Evolutionary Genomics, CNRS UMR8197, Institut de Biologie de l'Ecole Normale Supérieure, 46 rue d'Ulm, F-75230 Paris Cedex 05, FranceInstitut de Biologie Moléculaire des Plantes du CNRS (UPR2357), conventionné avec l'Université Louis Pasteur, Strasbourg, France.
authors.forename: Enric
authors.initials: E
authors.lastname: Castells
authors.forename: Jean
authors.initials: J
authors.lastname: Molinier
authors.forename: Stephanie
authors.initials: S
authors.lastname: Drevensek
authors.forename: Pascal
authors.initials: P
authors.lastname: Genschik
authors.forename: Fredy
authors.initials: F
authors.lastname: Barneche
authors.forename: Chris
authors.initials: C
authors.lastname: Bowler
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics*; D019755:Carbon-Carbon Lyases / Q000235:genetics*; D004249:DNA Damage; D004260:DNA Repair; D017343:Genes, Plant; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics*; D014466:Ultraviolet Rays
chemical_list: D029681:Arabidopsis Proteins; C514695:PHR1 protein, Arabidopsis; D014157:Transcription Factors; D019755:Carbon-Carbon Lyases; C110458:UVR3 protein, Arabidopsis