The ATR barrier to replication-born DNA damage

López-Contreras, Andrés J.; Fernández-Capetillo, Óscar

doi:10.1016/j.dnarep.2010.09.012

Cited by 126 publications

(115 citation statements)

References 90 publications

Supporting

Mentioning

109

Contrasting

Order By: Relevance

“…It is largely accepted that DSB either induced directly, or resulting from unrepaired SSB, or the replication-fork collapse initiate the DDR by activating the ATM kinase and DNA-PK, and subsequently, activation of the checkpoint kinase CHK2. Conversely, ssDNA repair intermediates and ssDNA that arises during replication stress recruit the ATR complex, 29 which subsequently entails the activation of another (23 kDa) and p21 (21 kDa) in whole extracts from myotubes exposed to DOXO (3 mM for 3 h) or MND (30 mM MND for 1 h). CTR, untreated control cells.…”

Section: Discussionmentioning

confidence: 99%

DNA damage response by single-strand breaks in terminally differentiated muscle cells and the control of muscle integrity

et al. 2012

View full text Add to dashboard Cite

DNA single-strand breaks (SSB) formation coordinates the myogenic program, and defects in SSB repair in post-mitotic cells have been associated with human diseases. However, the DNA damage response by SSB in terminally differentiated cells has not been explored yet. Here we show that mouse post-mitotic muscle cells accumulate SSB after alkylation damage, but they are extraordinarily resistant to the killing effects of a variety of SSB-inducers. We demonstrate that, upon SSB induction, phosphorylation of H2AX occurs in myotubes and is largely ataxia telangiectasia mutated (ATM)-dependent. However, the DNA damage signaling cascade downstream of ATM is defective as shown by lack of p53 increase and phosphorylation at serine 18 (human serine 15). The stabilization of p53 by nutlin-3 was ineffective in activating the cell death pathway, indicating that the resistance to SSB inducers is due to defective p53 downstream signaling. The induction of specific types of damage is required to activate the cell death program in myotubes. Besides the topoisomerase inhibitor doxorubicin known for its cardiotoxicity, we show that the mitochondria-specific inhibitor menadione is able to activate p53 and to kill effectively myotubes. Cell killing is p53-dependent as demonstrated by full protection of myotubes lacking p53, but there is a restriction of p53-activated genes. This new information may have important therapeutic implications in the prevention of muscle cell toxicity. Cells respond to genotoxic stress by activating a signaling cascade known as the DNA damage response (DDR). The DDR is a complex interlaced network comprised of DNA damage repair factors and cell cycle regulators. 1 Our knowledge of the mechanisms of DDR mainly relies on studies conducted in proliferating cells, in which the cell cycle machinery is integrated with the DNA damage signaling. Much less is known in post-mitotic cells that undergo irreversible cell cycle withdrawal. DNA repair is strongly affected by the exit from the cell cycle as revealed by downregulation of the major DNA repair pathways. 2 This occurs during differentiation-associated gene reprogramming at transcriptional level as in the case of genes coding for proteins shared by DNA repair and replication (e.g., replicative DNA polymerases, Flap structure-specific endonuclease 1, proliferating cell nuclear antigen and DNA ligase 1) 3 or repair proteins that are cell-cycle related (e.g., XRCC1 (X-ray repair complementing defective repair in Chinese hamster cells 1), uracil-DNA glycosylase). 4,5 Alternatively, post-translational modifications may modify the efficiency of specific DNA repair components as in the case of transcription factor II H that, because of reduced ubiquitination, may lead to decreased global genomic nucleotide excision repair typical of differentiated cells. 6 Exposure of single-stranded (ss) DNA and/or the generation of double-strand breaks (DSB) are powerful activators of DDR by recruiting and activating two protein kinases, ataxia telangiectasia and Rad3-related (ATR)...

show abstract

Section: Discussionmentioning

confidence: 99%

DNA damage response by single-strand breaks in terminally differentiated muscle cells and the control of muscle integrity

et al. 2012

View full text Add to dashboard Cite

show abstract

“…[5][6][7] Atr is activated by single strand DNA, such as those that accumulates during polymerase stalling during replicative stress. [8][9][10] There is significant overlap in the Atm and Atr signaling pathways and activation signals. 11 In addition, loss of function of one kinase results in compensatory upregulation of the other.…”

mentioning

confidence: 99%

The loss of the BH3-only Bcl-2 family member Bid delays T-cell leukemogenesis in Atm−/− mice

et al. 2013

View full text Add to dashboard Cite

Multicellular organisms maintain genomic integrity and resist tumorigenesis through a tightly regulated DNA damage response (DDR) that prevents propagation of deleterious mutations either through DNA repair or programmed cell death. An impaired DDR leads to tumorigenesis that is accelerated when programmed cell death is prevented. Loss of the ATM (ataxia telangiectasia mutated)-mediated DDR in mice results in T-cell leukemia driven by accumulation of DNA damage accrued during normal T-cell development. Pro-apoptotic BH3-only Bid is a substrate of Atm, and Bid phosphorylation is required for proper cell cycle checkpoint control and regulation of hematopoietic function. In this report, we demonstrate that, surprisingly, loss of Bid increases the latency of leukemogenesis in Atm À / À mice. Bid À / À Atm À / À mice display impaired checkpoint control and increased cell death of DN3 thymocytes. Loss of Bid thus inhibits T-cell tumorigenesis by increasing clearance of damaged cells, and preventing propagation of deleterious mutations.

show abstract

“…In brief, RS is defined by the accumulation of abnormal amounts of ssDNA at stalled replication forks that, due to its recombinogenic nature, can initiate genomic rearrangements. In mammals, RS is sensed and suppressed by a signaling cascade initiated by the ATR kinase, which, together with its target kinase, CHK1, suppresses RS through the phosphorylation of multiple targets (Cimprich and Cortez 2008;Lopez-Contreras and Fernandez-Capetillo 2010). ATR and CHK1 are essential for embryonic development in mice (Brown and Baltimore 2000;de Klein et al 2000;Liu et al 2000), which is due to the role of the RS response (RSR) in preventing replication-born chromosome breakage.…”

mentioning

confidence: 99%

IncreasedRrm2gene dosage reduces fragile site breakage and prolongs survival of ATR mutant mice

et al. 2015

Self Cite

View full text Add to dashboard Cite

In Saccharomyces cerevisiae, absence of the checkpoint kinase Mec1 (ATR) is viable upon mutations that increase the activity of the ribonucleotide reductase (RNR) complex. Whether this pathway is conserved in mammals remains unknown. Here we show that cells from mice carrying extra alleles of the RNR regulatory subunit RRM2 (Rrm2 TG ) present supraphysiological RNR activity and reduced chromosomal breakage at fragile sites. Moreover, increased Rrm2 gene dosage significantly extends the life span of ATR mutant mice. Our study reveals the first genetic condition in mammals that reduces fragile site expression and alleviates the severity of a progeroid disease by increasing RNR activity.Supplemental material is available for this article.Received December 5, 2014; revised version accepted March 2, 2015.Replication stress (RS) has emerged as a source of genome instability in human diseases, including cancer and premature aging (Lecona and Fernandez-Capetillo 2014;Zeman and Cimprich 2014). In brief, RS is defined by the accumulation of abnormal amounts of ssDNA at stalled replication forks that, due to its recombinogenic nature, can initiate genomic rearrangements. In mammals, RS is sensed and suppressed by a signaling cascade initiated by the ATR kinase, which, together with its target kinase, CHK1, suppresses RS through the phosphorylation of multiple targets (Cimprich and Cortez 2008;Lopez-Contreras and Fernandez-Capetillo 2010). ATR and CHK1 are essential for embryonic development in mice (Brown and Baltimore 2000;de Klein et al. 2000;Liu et al. 2000), which is due to the role of the RS response (RSR) in preventing replication-born chromosome breakage. Whether the RSR protects all forks or a subset of them during replication is unclear. On the one hand, proteomic studies of the human replisome in unchallenged conditions have failed to detect ATR or CHK1 in the vicinity of replication forks Sirbu et al. 2013), suggesting that their activity might be particularly necessary for only a subset of forks, such as damaged ones. Accordingly, chromosomal breaks that arise upon ATR inactivation locate preferentially at specific loci named common fragile sites (CFSs) (Casper et al. 2002) and early replicating fragile sites (ERFSs) (Barlow et al. 2013). Regardless of whether ATR works at all forks or only some of them, how it suppresses RS and why it is essential are still not fully understood.Ribonucleotide reductase (RNR) is a tetrameric enzyme composed of two catalytic (RRM1, Rnr1 in yeast) and two regulatory (RRM2, Rnr2 in yeast) subunits (Jordan and Reichard 1998). It reduces NDPs into dNDPs, which is a rate-limiting step for the production of dNTPs. In yeast, the lethality of mec1Δ strains can be bypassed by mutations that increase RNR activity. The first evidence of a connection between ATR and RNR came from the discovery of Crt1 (a transcriptional repressor of RNR subunits) as a suppressor of Mec1 lethality in Saccharomyces cerevisiae (Huang et al. 1998). Furthermore, overproduction of Rnr1 was shown to be sufficient ...

show abstract

The ATR barrier to replication-born DNA damage

Cited by 126 publications

References 90 publications

DNA damage response by single-strand breaks in terminally differentiated muscle cells and the control of muscle integrity

DNA damage response by single-strand breaks in terminally differentiated muscle cells and the control of muscle integrity

The loss of the BH3-only Bcl-2 family member Bid delays T-cell leukemogenesis in Atm−/− mice

IncreasedRrm2gene dosage reduces fragile site breakage and prolongs survival of ATR mutant mice

Contact Info

Product

Resources

About