title: The Fun30 nucleosome remodeller promotes resection of DNA double-strand break ends.
abstract: Chromosomal double-strand breaks (DSBs) are resected by 5' nucleases to form 3' single-stranded DNA substrates for binding by homologous recombination and DNA damage checkpoint proteins. Two redundant pathways of extensive resection have been described both in cells and in vitro, one relying on Exo1 exonuclease and the other on Sgs1 helicase and Dna2 nuclease. However, it remains unknown how resection proceeds within the context of chromatin, where histones and histone-bound proteins represent barriers for resection enzymes. Here we identify the yeast nucleosome-remodelling enzyme Fun30 as a factor promoting DSB end resection. Fun30 is the major nucleosome remodeller promoting extensive Exo1- and Sgs1-dependent resection of DSBs. The RSC and INO80 chromatin-remodelling complexes and Fun30 have redundant roles in resection adjacent to DSB ends. ATPase and helicase domains of Fun30, which are needed for nucleosome remodelling, are also required for resection. Fun30 is robustly recruited to DNA breaks and spreads along the DSB coincident with resection. Fun30 becomes less important for resection in the absence of the histone-bound Rad9 checkpoint adaptor protein known to block 5' strand processing and in the absence of either histone H3 K79 methylation or γ-H2A, which mediate recruitment of Rad9 (refs 9, 10). Together these data suggest that Fun30 helps to overcome the inhibitory effect of Rad9 on DNA resection.
authors.affiliation: Department of Molecular & Human Genetics, Baylor College of Medicine, One Baylor Plaza, Houston, Texas 77030, USA.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Chen
authors.forename: Dandan
authors.initials: D
authors.lastname: Cui
authors.forename: Alma
authors.initials: A
authors.lastname: Papusha
authors.forename: Xiaotian
authors.initials: X
authors.lastname: Zhang
authors.forename: Chia-Dwo
authors.initials: CD
authors.lastname: Chu
authors.forename: Jiangwu
authors.initials: J
authors.lastname: Tang
authors.forename: Kaifu
authors.initials: K
authors.lastname: Chen
authors.forename: Xuewen
authors.initials: X
authors.lastname: Pan
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Ira
mesh_terms: D018797:Cell Cycle Proteins / Q000378:metabolism; D042002:Chromatin Assembly and Disassembly; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair; D004271:DNA, Fungal / Q000235:genetics / Q000378:metabolism*; D005090:Exodeoxyribonucleases / Q000378:metabolism; D005800:Genes, Fungal / Q000235:genetics; D016681:Genome, Fungal / Q000235:genetics; D006657:Histones / Q000378:metabolism; D059765:Homologous Recombination; D008745:Methylation; D009707:Nucleosomes / Q000235:genetics / Q000378:metabolism*; D053484:RecQ Helicases / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D004271:DNA, Fungal; C074000:FUN30 protein, S cerevisiae; D006657:Histones; D009707:Nucleosomes; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; C069930:rad9 protein; D005090:Exodeoxyribonucleases; C028450:exodeoxyribonuclease I; C090472:SGS1 protein, S cerevisiae; D053484:RecQ Helicases