| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| The activation of Chk 1 depends on both Claspin and the upstream regulatory kinase ATR . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Claspin , a Chk 1 regulatory protein , monitors DNA replication on chromatin independently of RPA , ATR , and Rad 17 . ^^^ Claspin is required for the ATR dependent activation of Chk 1 in Xenopus egg extracts containing incompletely replicated DNA . ^^^ Claspin , ATR , and Rad 17 all bind to chromatin independently . ^^^ Claspin , ATR , and Rad 17 may collaborate in checkpoint regulation by detecting different aspects of a DNA replication fork . . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Moreover , Claspin interacts with the checkpoint proteins ATR and Rad 9 . ^^^ Given that both the ATR and Rad 9 Rad1 Hus 1 complexes are involved in Chk 1 activation , it is possible that Claspin works as an adaptor molecule bringing these molecules together . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Claspin and the activated form of ATR ATRIP collaborate in the activation of Chk 1 . ^^^ Claspin is necessary for the ATR dependent activation of Chk 1 in Xenopus egg extracts containing incompletely replicated DNA . ^^^ We have studied the respective roles of ATR ATRIP and Claspin in the activation of Chk 1 . ^^^ Without Claspin , activated ATR ATRIP phosphorylated Chk 1 weakly in a cell free reaction . ^^^ The addition of Claspin to this reaction strongly stimulated the phosphorylation of Chk 1 by ATR ATRIP . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Using a phosphopeptide derived from the consensus motif of these sites , we show that the interaction of Claspin with Chk 1 is required for the ATR / ATM dependent phosphorylation of Chk 1 . ^^^ Claspin is phosphorylated in the Chk 1 binding domain in an ATR / ATM dependent manner and is also targeted by additional kinases in response to double stranded DNA oligonucleotides . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| This accumulation is blocked by addition of caffeine and by immunodepletion of either ATR or Claspin . ^^^ These observations suggest that the increased binding of Drf 1 to aphidicolin treated chromatin is an active process that is mediated by a caffeine sensitive checkpoint pathway containing ATR and Claspin . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Phosphorylated claspin interacts with a phosphate binding site in the kinase domain of Chk 1 during ATR mediated activation . ^^^ Claspin is essential for the ATR dependent activation of Chk 1 in Xenopus egg extracts containing incompletely replicated or UV damaged DNA . ^^^ Overall , these results indicate that Claspin docks with a phosphate binding site in the catalytic domain of Chk 1 during activation by ATR . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Cell cycle association of ATR with chromatin mirrors that of RPA in addition to claspin , a cell cycle checkpoint protein previously shown to be a component of the replication machinery . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Phosphorylation of Claspin was found to depend on the ataxia telangiectasia mutated Rad 3 related ( ATR ) pathway . ^^^ Claspin was found to control BRCA 1 phosphorylation on serine 1524 , a site whose phosphorylation is controlled by the ATR pathway . ^^^ These results are consistent with a model in which ATR regulates Claspin phosphorylation in response to DNA damage and replication stress resulting in recruitment and phosphorylation of BRCA 1 . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| ATR , Claspin and the Rad 9 Rad1 Hus 1 complex regulate Chk 1 and Cdc25A in the absence of DNA damage . ^^^ ATR , with Claspin and the Rad 9 Rad1 Hus 1 complex , activates Chk 1 after DNA damage . ^^^ Here , we show that during physiological S phase the regulation of the Chk 1 Cdc25A pathway depends on ATR , Claspin , Rad 9 , and Hus 1 . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| This phosphorylation depends on Xenopus ATR ( Xatr ) and Xenopus Rad 17 ( Xrad 17 ) , but not Claspin . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| These findings reveal a phosphorylation dependent function of Rad 17 in an ATR Rad 17 Claspin Chk 1 signaling cascade that responds to specific replication stress . . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Claspin is required for the phosphorylation and activation of the Chk 1 protein kinase by ATR during DNA replication and in response to DNA damage . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Consistent with these events being triggered by active checkpoint signaling , inhibition of the DNA damage activated kinases ATR and ATM , or siRNA mediated downregulation of the DNA damage mediator proteins Claspin and TopBP 1 , impaired DNA damage induced dissociation of Chk 1 from chromatin . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Phosphorylation of Xenopus Rad 1 and Hus 1 defines a readout for ATR activation that is independent of Claspin and the Rad 9 carboxy terminus . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| The checkpoint mediator protein Claspin is indispensable for the ATR dependent phosphorylation of Chk 1 in response to stalled DNA replication forks in Xenopus egg extracts . ^^^ The function of Claspin in this DSB triggered pathway depends on phosphorylation of T 817 and S 819 by ATR . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Direct requirement for Xmus 101 in ATR mediated phosphorylation of Claspin bound Chk 1 during checkpoint signaling . ^^^ We find that Xmus 101 is essential for AT 70 mediated checkpoint signaling and that it functions to promote phosphorylation of Claspin bound Chk 1 by the ataxia telangiectasia and Rad 3 related ( ATR ) protein kinase . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Regulation of Claspin degradation by the ubiquitin proteosome pathway during the cell cycle and in response to ATR dependent checkpoint activation . ^^^ Claspin is involved in ATR dependent activation of Chk 1 during DNA replication and in response to DNA damage . ^^^ Claspin is stabilized in S phase but is abruptly degraded in mitosis and is absent from early G ( 1 ) cells in which the phosphorylation of Chk 1 by ATR is abrogated . ^^^ In response to hydroxyurea , UV or aphidicolin , Claspin is phosphorylated in the Chk 1 binding domain and its protein levels are increased in an ATR dependent manner . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| Claspin operates downstream of TopBP 1 to direct ATR signaling towards Chk 1 activation . ^^^ TopBP 1 and Claspin are adaptor proteins that facilitate phosphorylation of Chk 1 by the ATR kinase in response to genotoxic stress . ^^^ Consistently , the RNAi mediated ablation of Claspin selectively abrogated ATR ' s ability to phosphorylate Chk 1 but not other ATR targets . ^^^ Together , these results suggest that while TopBP 1 is a general regulator of ATR , Claspin operates downstream of TopBP 1 to selectively regulate the Chk 1 controlled branch of the genotoxic stress response . . ^^^ |
|
| Interacting proteins: Q9HAW4 and Q13535 |
Pubmed |
SVM Score :0.0 |
| During replicative stress , Claspin mediates the phosphorylation and consequent activation of Chk 1 by ATR . ^^^ |
|