title: Spontaneous and double-strand break-induced recombination, and gene conversion tract lengths, are differentially affected by overexpression of wild-type or ATPase-defective yeast Rad54.
abstract: Rad54 plays key roles in homologous recombination (HR) and double-strand break (DSB) repair in yeast, along with Rad51, Rad52, Rad55 and Rad57. Rad54 belongs to the Swi2/Snf2 family of DNA-stimulated ATPases. Rad51 nucleoprotein filaments catalyze DNA strand exchange and Rad54 augments this activity of Rad51. Mutations in the Rad54 ATPase domain (ATPase(-)) impair Rad54 function in vitro, sensitize yeast to killing by methylmethane sulfonate and reduce spontaneous gene conversion. We found that overexpression of ATPase(-) Rad54 reduced spontaneous direct repeat gene conversion and increased both spontaneous direct repeat deletion and spontaneous allelic conversion. Overexpression of ATPase(-) Rad54 decreased DSB-induced allelic conversion, but increased chromosome loss and DSB-dependent lethality. Thus, ATP hydrolysis by Rad54 contributes to genome stability by promoting high-fidelity DSB repair and suppressing spontaneous deletions. Overexpression of wild-type Rad54 did not alter DSB-induced HR levels, but conversion tract lengths were reduced. Interestingly, ATPase(-) Rad54 decreased overall HR levels and increased tract lengths. These tract length changes provide new in vivo evidence that Rad54 functions in the post-synaptic phase during recombinational repair of DSBs.
authors.affiliation: Department of Molecular Genetics and Microbiology, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA.
authors.forename: Perry M
authors.initials: PM
authors.lastname: Kim
authors.forename: Kimberly S
authors.initials: KS
authors.lastname: Paffett
authors.forename: Jachen A
authors.initials: JA
authors.lastname: Solinger
authors.forename: Wolf-Dietrich
authors.initials: WD
authors.lastname: Heyer
authors.forename: Jac A
authors.initials: JA
authors.lastname: Nickoloff
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects / Q000235:genetics; D004249:DNA Damage; D004265:DNA Helicases; D045643:DNA Repair Enzymes; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D005785:Gene Conversion / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D005838:Genotype; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D009154:Mutation; D011995:Recombination, Genetic / Q000235:genetics*; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000187:drug effects / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D017384:Sequence Deletion
chemical_list: D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; D008741:Methyl Methanesulfonate; D000251:Adenosine Triphosphatases; C075468:RAD54 protein, S cerevisiae; D004265:DNA Helicases; D045643:DNA Repair Enzymes