Mammalian Rad51C contributes to DNA cross-link resistance, sister chromatid cohesion and genomic stability.
The eukaryotic Rad51 protein is a structural and functional homolog of Escherichia coli RecA with a role in DNA repair and genetic recombination. Five paralogs of Rad51 have been identified in vertebrates, Rad51B, Rad51C, Rad51D, Xrcc2 and Xrcc3, which are also implicated in recombination and genome stability. Here, we identify a mammalian cell mutant in Rad51C. We show that the Chinese hamster cell mutant, CL-V4B, has a defect in Rad51C. Sequencing of the hamster Rad51C cDNA revealed a 132 bp deletion corresponding to an alternatively spliced transcript with lack of exon 5. CL-V4B was hypersensitive to the interstrand cross-linking agents mitomycin C (MMC) and cisplatinum, the alkylating agent methyl methanesulfonate and the topoisomerase I inhibitor campthotecin and showed impaired Rad51 foci formation in response to DNA damage. The defect in Rad51C also resulted in an increase of spontaneous and MMC-induced chromosomal aberrations as well as a lack of induction of sister chromatid exchanges. However, centrosome formation was not affected. Intriguingly, a reduced level of sister chromatid cohesion was found in CL-V4B cells. These results reveal a role for Rad51C that is unique among the Rad51 paralogs.
Godthelp
Barbara C
BC
Department of Radiation Genetics and Chemical Mutagenesis, Leiden University Medical Center, Wassenaarseweg 72, 2333 AL, Leiden, The Netherlands.
Wiegant
Wouter W
WW
van Duijn-Goedhart
Annemarie
A
Schärer
Orlando D
OD
van Buul
Paul P W
PP
Kanaar
Roland
R
Zdzienicka
Massgorzata Z
MZ
D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002842:Chromatids / Q000235:genetics*; D002869:Chromosome Aberrations; D020090:Chromosome Segregation / Q000235:genetics; D002886:Chromosomes, Human, Pair 17 / Q000235:genetics; D006224:Cricetinae; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004247:DNA / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D005816:Genetic Complementation Test; D016678:Genome; D006801:Humans; D016685:Mitomycin / Q000494:pharmacology; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D051135:Rad51 Recombinase; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D003432:Cross-Linking Reagents; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C448305:RAD51C protein, human; D016685:Mitomycin; D004247:DNA; C495153:RAD51 protein, human; D051135:Rad51 Recombinase