TY - JOUR
T1 - Critical roles of ring finger protein RNF8 in replication stress responses
AU - Sy, Shirley M.H.
AU - Jiang, Jun
AU - Dong, Sui Sui
AU - Lok, Gabriel Tsz Mei
AU - Wu, Jun
AU - Cai, Hua
AU - Yeung, Enoch S.L.
AU - Huang, Jun
AU - Chen, Junjie
AU - Deng, Yiqun
AU - Huen, Michael S.Y.
PY - 2011/6/24
Y1 - 2011/6/24
N2 - Histone ubiquitylation is emerging as an important protective component in cellular responses to DNA damage. The ubiquitin ligases RNF8 and RNF168 assemble ubiquitin chains onto histone molecules surrounding DNA breaks and facilitate retention of DNA repair proteins. Although RNF8 and RNF168 play important roles in repair of DNA double strand breaks, their requirement for cell protection from replication stress is largely unknown. In this study, we uncovered RNF168-independent roles of RNF8 in repair of replication inhibition-induced DNA damage. We showed that RNF8 depletion, but not RNF168 depletion, hyper-sensitized cells to hydroxyurea and aphidicolin treatment. Consistently, hydroxyurea induced persistent single strand DNA lesions and sustained CHK1 activation in RNF8-depleted cells. In line with strict requirement for RAD51-dependent repair of hydroxyurea-stalled replication forks, RNF8 depletion compromised RAD51 accumulation onto single strand DNA lesions, suggesting that impaired replication fork repair may underlie the enhanced cellular sensitivity to replication arrest observed in RNF8-depleted cells. In total, our study highlights the differential requirement for the ubiquitin ligase RNF8 in facilitating repair of replication stress-associated DNA damage.
AB - Histone ubiquitylation is emerging as an important protective component in cellular responses to DNA damage. The ubiquitin ligases RNF8 and RNF168 assemble ubiquitin chains onto histone molecules surrounding DNA breaks and facilitate retention of DNA repair proteins. Although RNF8 and RNF168 play important roles in repair of DNA double strand breaks, their requirement for cell protection from replication stress is largely unknown. In this study, we uncovered RNF168-independent roles of RNF8 in repair of replication inhibition-induced DNA damage. We showed that RNF8 depletion, but not RNF168 depletion, hyper-sensitized cells to hydroxyurea and aphidicolin treatment. Consistently, hydroxyurea induced persistent single strand DNA lesions and sustained CHK1 activation in RNF8-depleted cells. In line with strict requirement for RAD51-dependent repair of hydroxyurea-stalled replication forks, RNF8 depletion compromised RAD51 accumulation onto single strand DNA lesions, suggesting that impaired replication fork repair may underlie the enhanced cellular sensitivity to replication arrest observed in RNF8-depleted cells. In total, our study highlights the differential requirement for the ubiquitin ligase RNF8 in facilitating repair of replication stress-associated DNA damage.
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U2 - 10.1074/jbc.M111.232041
DO - 10.1074/jbc.M111.232041
M3 - Article
C2 - 21558560
AN - SCOPUS:79959326643
SN - 0021-9258
VL - 286
SP - 22355
EP - 22361
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 25
ER -