title: The AtRAD21.1 and AtRAD21.3 Arabidopsis cohesins play a synergistic role in somatic DNA double strand break damage repair.
abstract: BACKGROUND
  The RAD21 cohesin plays, besides its well-recognised role in chromatid cohesion, a role in DNA double strand break (dsb) repair. In Arabidopsis there are three RAD21 paralog genes (AtRAD21.1, AtRAD21.2 and AtRAD21.3), yet only AtRAD21.1 has been shown to be required for DNA dsb damage repair. Further investigation of the role of cohesins in DNA dsb repair was carried out and is here reported.
  
  
  RESULTS
  We show for the first time that not only AtRAD21.1 but also AtRAD21.3 play a role in somatic DNA dsb repair. Comet data shows that the lack of either cohesins induces a similar high basal level of DNA dsb in the nuclei and a slower DNA dsb repair kinetics in both cohesin mutants. The observed AtRAD21.3 transcriptional response to DNA dsb induction reinforces further the role of this cohesin in DNA dsb repair. The importance of AtRAD21.3 in DNA dsb damage repair, after exposure to DNA dsb damage inducing agents, is notorious and recognisably evident at the phenotypical level, particularly when the AtRAD21.1 gene is also disrupted.
  
  
  CONCLUSIONS
  Our data demonstrates that both Arabidopsis cohesin (AtRAD21.1 and AtRAD21.3) play a role in somatic DNA dsb repair. Furthermore, the phenotypical data from the atrad21.1 atrad21.3 double mutant indicates that these two cohesins function synergistically in DNA dsb repair. The implications of this data are discussed.
authors.forename: José A
authors.initials: JA
authors.lastname: da Costa-Nunes
authors.forename: Cláudio
authors.initials: C
authors.lastname: Capitão
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Kozak
authors.forename: Pedro
authors.initials: P
authors.lastname: Costa-Nunes
authors.forename: Gloria M
authors.initials: GM
authors.lastname: Ducasa
authors.forename: Olga
authors.initials: O
authors.lastname: Pontes
authors.forename: Karel J
authors.initials: KJ
authors.lastname: Angelis
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism*; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair / Q000235:genetics*; D018744:DNA, Plant / Q000235:genetics* / Q000378:metabolism; D060888:Real-Time Polymerase Chain Reaction
chemical_list: D029681:Arabidopsis Proteins; D002868:Chromosomal Proteins, Non-Histone; D018744:DNA, Plant; C510670:RAD21.2 protein, Arabidopsis; C510671:RAD21.3 protein, Arabidopsis