title: Arabidopsis TAF1 is an MRE11-interacting protein required for resistance to genotoxic stress and viability of the male gametophyte.
abstract: Repair of DNA double-strand breaks (DSBs) by recombination pathways is essential for plant growth and fertility. The recombination endonuclease MRE11 plays important roles in sensing and repair of DNA DSBs. Here we demonstrate protein interaction between Arabidopsis MRE11 and the histone acetyltransferase TAF1, a TATA-binding protein Associated Factor (TAF) of the RNA polymerase II transcription initiation factor complex TFIID. Arabidopsis has two TAF1 homologues termed TAF1 and TAF1b and mutant taf1b lines are viable and fertile. In contrast, taf1 null mutations are lethal, demonstrating that TAF1 is an essential gene. Heterozygous taf1+/- plants display abnormal segregation of the mutant allele resulting from defects in pollen tube development, indicating that TAF1 is important for gamete viability. Characterization of an allelic series of taf1 lines revealed that hypomorphic mutants are viable but display developmental defects and reduced plant fertility. Hypersensitivity of taf1 mutants lacking the C-terminal bromodomain to X-rays and mitomycin C, but not to other forms of abiotic stress, established a specific role for TAF1 in plant DNA repair processes. Collectively these studies reveal a function for TAF1 in plant resistance to genotoxic stress, providing further insight into the molecular mechanisms of the DNA damage response in plants.
authors.affiliation: Centre for Plant Sciences, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
authors.forename: Wanda M
authors.initials: WM
authors.lastname: Waterworth
authors.affiliation: Centre for Plant Sciences, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
authors.forename: Georgina E
authors.initials: GE
authors.lastname: Drury
authors.affiliation: Centre for Plant Sciences, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
authors.forename: George
authors.initials: G
authors.lastname: Blundell-Hunter
authors.affiliation: Centre for Plant Sciences, University of Leeds, Woodhouse Lane, Leeds, LS2 9JT, UK.
authors.forename: Christopher E
authors.initials: CE
authors.lastname: West
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D053903:DNA Breaks, Double-Stranded; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D000076228:MRE11 Homologue Protein; D016685:Mitomycin / Q000494:pharmacology; D009154:Mutation; D011058:Pollen / Q000502:physiology*; D053205:Pollen Tube / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C496704:HAF2 protein, Arabidopsis; C492900:Mre11 protein, Arabidopsis; D014157:Transcription Factors; D016685:Mitomycin; D000076228:MRE11 Homologue Protein
keywords: Arabidopsis thaliana; DNA double-strand break; DNA repair; recombination; transcription