Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-3844
El-Shemerly, M; Hess, D; Pyakurel, A K; Moselhy, S; Ferrari, S (2008). ATR-dependent pathways control hEXO1 stability in response to stalled forks. Nucleic Acids Research, 36(2):511-519.
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Nucleases play important roles in DNA synthesis, recombination and repair. We have previously shown that human exonuclease 1 (hEXO1) is phosphorylated in response to agents stalling DNA replication and that hEXO1 consequently undergoes ubiquitination and degradation in a proteasome-dependent manner. In the present study, we have addressed the identity of the pathway transducing stalled-replication signals to hEXO1. Using chemical inhibitors, RNA interference, ATM- and ATR-deficient cell lines we have concluded that hEXO1 phosphorylation is ATR-dependent. By means of mass spectrometry, we have identified the sites of phosphorylation in hEXO1 in undamaged cells and in cells treated with hydroxyurea (HU). hEXO1 is phosphorylated at nine basal sites and three additional sites are induced by HU treatment. Analysis of single- and multiple-point mutants revealed that mutation to Ala of the three HU-induced sites of phosphorylation partially rescued HU-dependent degradation of hEXO1 and additionally stabilized the protein in non-treated cells. We have raised an antibody to pS(714), an HU-induced site of the S/T-Q type, and we provide evidence that S(714) is phosphorylated upon HU but not IR treatment. The antibody may be a useful tool to monitor signal transduction events triggered by stalled DNA replication.
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|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||04 Faculty of Medicine > Institute of Molecular Cancer Research
07 Faculty of Science > Institute of Molecular Cancer Research
|DDC:||570 Life sciences; biology|
|Deposited On:||17 Sep 2008 12:43|
|Last Modified:||27 Nov 2013 18:54|
|Publisher:||Oxford University Press|
|Additional Information:||Full final text Oxford Journal|
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