Abstract
FANCM is the most highly conserved protein within the Fanconi anaemia (FA) tumour suppressor pathway. However, although FANCM contains a helicase domain with translocase activity, this is not required for its role in activating the FA pathway. Instead, we show here that FANCM translocaseactivity is essential for promoting replication fork stability. We demonstrate that cells expressing translocase-defective FANCM show altered global replication dynamics due to increased accumulation of stalled forks that subsequently degenerate into DNA double-strand breaks, leading to ATM activation, CTBP-interacting protein (CTIP)-dependent end resection and homologous recombination repair. Accordingly, abrogation of ATM or CTIP function in FANCM-deficient cells results in decreased cell survival. We also found that FANCM translocase activity protects cells from accumulating 53BP1-OPT domains, which mark lesions resulting from problems arising during replication. Taken together, these data show that FANCM plays an essential role in maintaining chromosomal integrity by promoting the recovery of stalled replication forks and hence preventing tumourigenesis.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Animals
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Ataxia Telangiectasia Mutated Proteins
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Cell Cycle Proteins / metabolism
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Cell Line
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DNA Breaks, Double-Stranded
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DNA Helicases / antagonists & inhibitors
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DNA Helicases / genetics
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DNA Helicases / metabolism*
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DNA Repair
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DNA Replication / genetics
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DNA Replication / physiology*
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DNA-Binding Proteins / metabolism
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Fanconi Anemia / genetics
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Fanconi Anemia / metabolism
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Gene Knockout Techniques
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HEK293 Cells
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HeLa Cells
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Homologous Recombination
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Humans
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Intracellular Signaling Peptides and Proteins / metabolism
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Models, Biological
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Nucleotide Transport Proteins / antagonists & inhibitors
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Nucleotide Transport Proteins / genetics
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Nucleotide Transport Proteins / metabolism*
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Protein Serine-Threonine Kinases / metabolism
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RNA, Small Interfering / genetics
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Tumor Suppressor Proteins / metabolism
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Tumor Suppressor p53-Binding Protein 1
Substances
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Cell Cycle Proteins
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DNA-Binding Proteins
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Intracellular Signaling Peptides and Proteins
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Nucleotide Transport Proteins
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RNA, Small Interfering
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TP53BP1 protein, human
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Tumor Suppressor Proteins
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Tumor Suppressor p53-Binding Protein 1
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ATM protein, human
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Ataxia Telangiectasia Mutated Proteins
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Protein Serine-Threonine Kinases
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FANCM protein, human
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DNA Helicases