FBH1 co-operates with MUS81 in inducing DNA double-strand breaks and cell death following replication stress.
The molecular events occurring following the disruption of DNA replication forks are poorly characterized, despite extensive use of replication inhibitors such as hydroxyurea in the treatment of malignancies. Here, we identify a key role for the FBH1 helicase in mediating DNA double-strand break formation following replication inhibition. We show that FBH1-deficient cells are resistant to killing by hydroxyurea, and exhibit impaired activation of the pro-apoptotic factor p53, consistent with decreased DNA double-strand break formation. Similar findings were obtained in murine ES cells carrying disrupted alleles of Fbh1. We also show that FBH1 through its helicase activity co-operates with the MUS81 nuclease in promoting the endonucleolytic DNA cleavage following prolonged replication stress. Accordingly, MUS81 and EME1-depleted cells show increased resistance to the cytotoxic effects of replication stress. Our data suggest that FBH1 helicase activity is required to eliminate cells with excessive replication stress through the generation of MUS81-induced DNA double-strand breaks.
Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Ole Maaløes Vej 5, Copenhagen N DK-2200, Denmark.
Kasper
K
Fugger
Wai Kit
WK
Chu
Peter
P
Haahr
Arne Nedergaard
AN
Kousholt
Halfdan
H
Beck
Miranda J
MJ
Payne
Katsuhiro
K
Hanada
Ian D
ID
Hickson
Claus Storgaard
CS
Sørensen
D000483:Alleles; D000818:Animals; D015139:Blotting, Southern; D016923:Cell Death / Q000187:drug effects; D045744:Cell Line, Tumor; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects; D004265:DNA Helicases / Q000378:metabolism*; D004261:DNA Replication / Q000187:drug effects; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004318:Doxycycline / Q000494:pharmacology; D053595:Embryonic Stem Cells / Q000166:cytology / Q000187:drug effects / Q000201:enzymology; D004720:Endonucleases / Q000378:metabolism*; D044783:F-Box Proteins / Q000378:metabolism*; D006801:Humans; D051379:Mice; D034741:RNA, Small Interfering / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D013312:Stress, Physiological / Q000187:drug effects
D004268:DNA-Binding Proteins; D044783:F-Box Proteins; D034741:RNA, Small Interfering; D004720:Endonucleases; C498772:MUS81 protein, human; C498773:Mus81 protein, mouse; D004265:DNA Helicases; C464443:FBH1 protein, human; C553250:Fbh1 protein, mouse; D004318:Doxycycline