Arabidopsis TAF1 is an MRE11‐interacting protein required for resistance to genotoxic stress and viability of the male gametophyte

• Published in: The Plant journal : for cell and molecular biology 2015-11, Vol.84 (3), p.545-557
• Main Authors: Waterworth, Wanda M., Drury, Georgina E., Blundell‐Hunter, George, West, Christopher E.
• Format: Article
• Language: English
• Subjects: Arabidopsis - drug effects; Arabidopsis - genetics; Arabidopsis - physiology; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Deoxyribonucleic acid; DNA; DNA Breaks, Double-Stranded; DNA Damage; DNA double‐strand break; DNA repair; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Gene Expression Regulation, Plant; Mitomycin - pharmacology; MRE11 Homologue Protein; Mutation; Original; Plant reproduction; Plant resistance; Pollen - physiology; Pollen Tube - genetics; Pollen Tube - metabolism; Protein Structure, Tertiary; Proteins; recombination; transcription; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 0960-7412; 1365-313X
• DOI: 10.1111/tpj.13020

Summary 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. Significance Statement DNA recombination pathways are critical for genome stability, fertility and survival of organisms. Here we establish a molecular link between a recombination endonuclease and a histone acetyltransferase involved in transcription initiation, providing insight into chromosomal break detection and DNA repair processes.