The Rad17 homologue of Arabidopsis is involved in the regulation of DNA damage repair and homologous recombination.
Rad17 is involved in DNA checkpoint control in yeast and human cells. A homologue of this gene as well as other genes of the pathway (the 9-1-1 complex) are present in Arabidopsis and share conserved sequence domains with their yeast and human counterparts. DNA-damaging agents induce AtRAD17 transcriptionally. AtRAD17 mutants show increased sensitivity to the DNA-damaging chemicals bleomycin and mitomycin C (MMC), which can be reversed by complementation, suggesting that the loss of function of Rad17 disturbs DNA repair in plant cells. Our results are further confirmed by the phenotype of a mutant of the 9-1-1 complex (Rad9), which is also sensitive to the same chemicals. AtRAD9 and AtRAD17 seem to be epistatic as the double mutant is not more sensitive to the chemicals than the single mutants. The mutants show a delay in the general repair of double-strand breaks (DSBs). However, frequencies of intrachromosomal homologous recombination (HR) are enhanced. Nevertheless, the mutants are proficient for a further induction of HR by genotoxic stresses. Our results indicate that a mutant Rad17 pathway is associated with a general deregulation of DNA repair, which seems to be correlated with a deficiency in non-homologous DSB repair.
Heitzeberg
Fabian
F
Institute of Plant Genetics and Crop Plant Research (IPK), Corrensstrasse 3, D-06466 Gatersleben, Germany.
Chen
I-Peng
IP
Hartung
Frank
F
Orel
Nadiya
N
Angelis
Karel J
KJ
Puchta
Holger
H
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000502:physiology*; D004249:DNA Damage / Q000502:physiology*; D004260:DNA Repair / Q000502:physiology*; D018076:DNA, Complementary / Q000032:analysis; D004268:DNA-Binding Proteins; D004720:Endonucleases / Q000302:isolation & purification; D008969:Molecular Sequence Data; D011995:Recombination, Genetic; D029702:Schizosaccharomyces pombe Proteins; D017386:Sequence Homology, Amino Acid
D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C501393:RAD17 protein, Arabidopsis; D029702:Schizosaccharomyces pombe Proteins; C106332:hus1 protein, S pombe; C069930:rad9 protein; D004720:Endonucleases