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J Biol Chem
2015 May 08;29019:12300-12. doi: 10.1074/jbc.M115.644005.
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14-3-3 proteins restrain the Exo1 nuclease to prevent overresection.
Chen X
,
Kim IK
,
Honaker Y
,
Paudyal SC
,
Koh WK
,
Sparks M
,
Li S
,
Piwnica-Worms H
,
Ellenberger T
,
You Z
.
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The DNA end resection process dictates the cellular response to DNA double strand break damage and is essential for genome maintenance. Although insufficient DNA resection hinders homology-directed repair and ATR (ataxia telangiectasia and Rad3 related)-dependent checkpoint activation, overresection produces excessive single-stranded DNA that could lead to genomic instability. However, the mechanisms controlling DNA end resection are poorly understood. Here we show that the major resection nuclease Exo1 is regulated both positively and negatively by protein-protein interactions to ensure a proper level of DNA resection. We have shown previously that the sliding DNA clamp proliferating cell nuclear antigen (PCNA) associates with the C-terminal domain of Exo1 and promotes Exo1 damage association and DNA resection. In this report, we show that 14-3-3 proteins interact with a central region of Exo1 and negatively regulate Exo1 damage recruitment and subsequent resection. 14-3-3s limit Exo1 damage association, at least in part, by suppressing its association with PCNA. Disruption of the Exo1 interaction with 14-3-3 proteins results in elevated sensitivity of cells to DNA damage. Unlike Exo1, the Dna2 resection pathway is apparently not regulated by PCNA and 14-3-3s. Our results provide critical insights into the mechanism and regulation of the DNA end resection process and may have implications for cancer treatment.
FIGURE 5.
The central region of Exo1 limits DNA end resection activity in a Xenopus egg extract. A, immunodepletion (depl) of the Xenopus Dna2 protein (xDna2) or of both xDna2 and xExo1 from the Xenopus NPE. B, physical association of Exo1(WT)-His and Exo1(ÎCR)-His with a bead-immobilized, 2-kb DNA fragment in xExo1-depleted NPE. C, DNA end resection activity toward a 3â² 32P-labeled, 6-kb dsDNA fragment in the Exo1 and Dna2 codepleted NPE depicted in A that was supplemented with Exo1(WT)-His or Exo1(ÎCR)-His. Vertical lines were added for sample lane identification.
FIGURE 6.
14-3-3 proteins repress Exo1-mediated DNA end resection in a Xenopus egg extract. A, purified recombinant GST, GST-Difopein(WT), and GST-Difopein(MUT) were expressed in and purified from BL21(DE3) E. coli cells. MW, molecular weight. B, effects of GST, GST-Difopein(WT), or GST-Difopein(MUT) on the association of xExo1 with 14-3-3 proteins in the Xenopus NPE. The asterisk denotes a nonspecific band detected by the anti-14-3-3 antibody. IP, immunoprecipitation. C, effects of GST, GST-Difopein(WT) or GST-Difopein(MUT) on DNA end resection in the extract. Vertical lines were added for sample lane identification. D, effects of GST-Difopein(WT) or GST-Difopein(MUT) on DNA end resection in the mock-depleted (depl) and xExo1-depleted or xDna2-depleted extracts. Vertical lines were added for sample lane identification. E, effects of GST-Difopein(WT) or GST-Difopein(MUT) on DNA end resection mediated by added Exo1(WT)-His or Exo1(ÎCR)-His in the extract depleted of both xExo1 and xDna2. Vertical lines were added for sample lane identification.
Adkins,
Nucleosome dynamics regulates DNA processing.
2013, Pubmed
Adkins,
Nucleosome dynamics regulates DNA processing.
2013,
Pubmed
Andersen,
14-3-3 checkpoint regulatory proteins interact specifically with DNA repair protein human exonuclease 1 (hEXO1) via a semi-conserved motif.
2012,
Pubmed
Bardwell,
Altered somatic hypermutation and reduced class-switch recombination in exonuclease 1-mutant mice.
2004,
Pubmed
Bertuch,
EXO1 contributes to telomere maintenance in both telomerase-proficient and telomerase-deficient Saccharomyces cerevisiae.
2004,
Pubmed
Bolderson,
Phosphorylation of Exo1 modulates homologous recombination repair of DNA double-strand breaks.
2010,
Pubmed
Bonetti,
Escape of Sgs1 from Rad9 inhibition reduces the requirement for Sae2 and functional MRX in DNA end resection.
2015,
Pubmed
Cannavo,
Relationship of DNA degradation by Saccharomyces cerevisiae exonuclease 1 and its stimulation by RPA and Mre11-Rad50-Xrs2 to DNA end resection.
2013,
Pubmed
Chen,
RPA coordinates DNA end resection and prevents formation of DNA hairpins.
2013,
Pubmed
Chen,
PCNA promotes processive DNA end resection by Exo1.
2013,
Pubmed
,
Xenbase
Ciccia,
The DNA damage response: making it safe to play with knives.
2010,
Pubmed
Cimprich,
ATR: an essential regulator of genome integrity.
2008,
Pubmed
Costanzo,
Xenopus cell-free extracts to study DNA damage checkpoints.
2004,
Pubmed
,
Xenbase
Cotta-Ramusino,
Exo1 processes stalled replication forks and counteracts fork reversal in checkpoint-defective cells.
2005,
Pubmed
Eid,
DNA end resection by CtIP and exonuclease 1 prevents genomic instability.
2010,
Pubmed
El-Shemerly,
ATR-dependent pathways control hEXO1 stability in response to stalled forks.
2008,
Pubmed
Engels,
14-3-3 Proteins regulate exonuclease 1-dependent processing of stalled replication forks.
2011,
Pubmed
Gravel,
DNA helicases Sgs1 and BLM promote DNA double-strand break resection.
2008,
Pubmed
Halazonetis,
An oncogene-induced DNA damage model for cancer development.
2008,
Pubmed
Hoeijmakers,
DNA damage, aging, and cancer.
2009,
Pubmed
Huertas,
DNA resection in eukaryotes: deciding how to fix the break.
2010,
Pubmed
Jackson,
The DNA-damage response in human biology and disease.
2009,
Pubmed
Karanja,
Preventing over-resection by DNA2 helicase/nuclease suppresses repair defects in Fanconi anemia cells.
2014,
Pubmed
Karras,
Noncanonical role of the 9-1-1 clamp in the error-free DNA damage tolerance pathway.
2013,
Pubmed
Kim,
Structure of mammalian poly(ADP-ribose) glycohydrolase reveals a flexible tyrosine clasp as a substrate-binding element.
2012,
Pubmed
Knipscheer,
Replication-coupled DNA interstrand cross-link repair in Xenopus egg extracts.
2012,
Pubmed
,
Xenbase
Langerak,
Release of Ku and MRN from DNA ends by Mre11 nuclease activity and Ctp1 is required for homologous recombination repair of double-strand breaks.
2011,
Pubmed
Liao,
Identification of the Xenopus DNA2 protein as a major nuclease for the 5'->3' strand-specific processing of DNA ends.
2008,
Pubmed
,
Xenbase
Liao,
Mechanistic analysis of Xenopus EXO1's function in 5'-strand resection at DNA double-strand breaks.
2011,
Pubmed
,
Xenbase
Lieber,
The mechanism of double-strand DNA break repair by the nonhomologous DNA end-joining pathway.
2010,
Pubmed
Lord,
The DNA damage response and cancer therapy.
2012,
Pubmed
Maringele,
Telomerase- and recombination-independent immortalization of budding yeast.
2004,
Pubmed
Masters,
14-3-3 proteins mediate an essential anti-apoptotic signal.
2001,
Pubmed
Mimitou,
Ku prevents Exo1 and Sgs1-dependent resection of DNA ends in the absence of a functional MRX complex or Sae2.
2010,
Pubmed
Mimitou,
Sae2, Exo1 and Sgs1 collaborate in DNA double-strand break processing.
2008,
Pubmed
Mimitou,
DNA end resection: many nucleases make light work.
2009,
Pubmed
Morin,
Checkpoint-dependent phosphorylation of Exo1 modulates the DNA damage response.
2008,
Pubmed
Morrison,
The 14-3-3 proteins: integrators of diverse signaling cues that impact cell fate and cancer development.
2009,
Pubmed
Moynahan,
Mitotic homologous recombination maintains genomic stability and suppresses tumorigenesis.
2010,
Pubmed
Ngo,
The 9-1-1 checkpoint clamp stimulates DNA resection by Dna2-Sgs1 and Exo1.
2014,
Pubmed
Nicolette,
Mre11-Rad50-Xrs2 and Sae2 promote 5' strand resection of DNA double-strand breaks.
2010,
Pubmed
Nimonkar,
BLM-DNA2-RPA-MRN and EXO1-BLM-RPA-MRN constitute two DNA end resection machineries for human DNA break repair.
2011,
Pubmed
Nimonkar,
Human exonuclease 1 and BLM helicase interact to resect DNA and initiate DNA repair.
2008,
Pubmed
Pei,
MMSET regulates histone H4K20 methylation and 53BP1 accumulation at DNA damage sites.
2011,
Pubmed
Peng,
Mitotic and G2 checkpoint control: regulation of 14-3-3 protein binding by phosphorylation of Cdc25C on serine-216.
1997,
Pubmed
Pommier,
Topoisomerase I inhibitors: camptothecins and beyond.
2006,
Pubmed
Reinhardt,
Phospho-Ser/Thr-binding domains: navigating the cell cycle and DNA damage response.
2013,
Pubmed
Rossiello,
Irreparable telomeric DNA damage and persistent DDR signalling as a shared causative mechanism of cellular senescence and ageing.
2014,
Pubmed
Sartori,
Human CtIP promotes DNA end resection.
2007,
Pubmed
Schaetzlein,
Mammalian Exo1 encodes both structural and catalytic functions that play distinct roles in essential biological processes.
2013,
Pubmed
Schaetzlein,
Exonuclease-1 deletion impairs DNA damage signaling and prolongs lifespan of telomere-dysfunctional mice.
2007,
Pubmed
Segurado,
Separate roles for the DNA damage checkpoint protein kinases in stabilizing DNA replication forks.
2008,
Pubmed
Shiloh,
The ATM protein kinase: regulating the cellular response to genotoxic stress, and more.
2013,
Pubmed
Shiloh,
The ATM protein kinase: regulating the cellular response to genotoxic stress, and more.
2013,
Pubmed
Shim,
Saccharomyces cerevisiae Mre11/Rad50/Xrs2 and Ku proteins regulate association of Exo1 and Dna2 with DNA breaks.
2010,
Pubmed
Shiotani,
Single-stranded DNA orchestrates an ATM-to-ATR switch at DNA breaks.
2009,
Pubmed
Shiotani,
Two distinct modes of ATR activation orchestrated by Rad17 and Nbs1.
2013,
Pubmed
Stracker,
The ATM signaling network in development and disease.
2013,
Pubmed
Sun,
Human Ku70/80 protein blocks exonuclease 1-mediated DNA resection in the presence of human Mre11 or Mre11/Rad50 protein complex.
2012,
Pubmed
Symington,
Double-strand break end resection and repair pathway choice.
2011,
Pubmed
Toledo,
ATR prohibits replication catastrophe by preventing global exhaustion of RPA.
2013,
Pubmed
Tomimatsu,
Phosphorylation of EXO1 by CDKs 1 and 2 regulates DNA end resection and repair pathway choice.
2014,
Pubmed
Tran,
EXO1-A multi-tasking eukaryotic nuclease.
2004,
Pubmed
Tsutakawa,
The cutting edges in DNA repair, licensing, and fidelity: DNA and RNA repair nucleases sculpt DNA to measure twice, cut once.
2014,
Pubmed
Walter,
Regulated chromosomal DNA replication in the absence of a nucleus.
1998,
Pubmed
,
Xenbase
Wang,
Isolation of high-affinity peptide antagonists of 14-3-3 proteins by phage display.
1999,
Pubmed
Wei,
Inactivation of Exonuclease 1 in mice results in DNA mismatch repair defects, increased cancer susceptibility, and male and female sterility.
2003,
Pubmed
Xu,
14-3-3 adaptor proteins recruit AID to 5'-AGCT-3'-rich switch regions for class switch recombination.
2010,
Pubmed
Yang,
The SOSS1 single-stranded DNA binding complex promotes DNA end resection in concert with Exo1.
2013,
Pubmed
You,
CtIP links DNA double-strand break sensing to resection.
2009,
Pubmed
,
Xenbase
Zhang,
Fission yeast Pxd1 promotes proper DNA repair by activating Rad16XPF and inhibiting Dna2.
2014,
Pubmed
Zhu,
Sgs1 helicase and two nucleases Dna2 and Exo1 resect DNA double-strand break ends.
2008,
Pubmed
Zou,
Sensing DNA damage through ATRIP recognition of RPA-ssDNA complexes.
2003,
Pubmed
