TY - JOUR
T1 - Homologous recombination but not nucleotide excision repair plays a pivotal role in tolerance of DNA-protein cross-links in mammalian cells
AU - Nakano, Toshiaki
AU - Katafuchi, Atsushi
AU - Matsubara, Mayumi
AU - Terato, Hiroaki
AU - Tsuboi, Tomohiro
AU - Masuda, Tasuku
AU - Tatsumoto, Takahiro
AU - Pil Pack, Seung
AU - Makino, Keisuke
AU - Croteau, Deborah L.
AU - Van Houten, Bennett
AU - Iijima, Kenta
AU - Tauchi, Hiroshi
AU - Ide, Hiroshi
PY - 2009/10/2
Y1 - 2009/10/2
N2 - DNA-protein cross-links (DPCs) are unique among DNA lesions in their unusually bulky nature. The steric hindrance imposed by cross-linked proteins (CLPs) will hamper DNA transactions, such as replication and transcription, posing an enormous threat to cells. In bacteria, DPCs with small CLPs are eliminated by nucleotide excision repair (NER), whereas oversized DPCs are processed exclusively by RecBCD-dependent homologous recombination (HR). Here we have assessed the roles of NER and HR for DPCs in mammalian cells. We show that the upper size limit of CLPs amenable to mammalian NER is relatively small (8-10 kDa) so that NER cannot participate in the repair of chromosomal DPCs in mammalian cells. Moreover, CLPs are not polyubiquitinated and hence are not subjected to proteasomal degradation prior to NER. In contrast, HR constitutes the major pathway in tolerance of DPCs as judged from cell survival and RAD51 and γ-H2AX nuclear foci formation. Induction of DPCs results in the accumulation of DNA double strand breaks in HR-deficient but not HR-proficient cells, suggesting that fork breakage at the DPC site initiates HR and reactivates the stalled fork. DPCs activate both ATR and ATMdamage response pathways, but there is a time lag between two responses. These results highlight the differential involvement of NER in the repair of DPCs in bacterial and mammalian cells and demonstrate the versatile and conserved role of HR in tolerance of DPCs among species.
AB - DNA-protein cross-links (DPCs) are unique among DNA lesions in their unusually bulky nature. The steric hindrance imposed by cross-linked proteins (CLPs) will hamper DNA transactions, such as replication and transcription, posing an enormous threat to cells. In bacteria, DPCs with small CLPs are eliminated by nucleotide excision repair (NER), whereas oversized DPCs are processed exclusively by RecBCD-dependent homologous recombination (HR). Here we have assessed the roles of NER and HR for DPCs in mammalian cells. We show that the upper size limit of CLPs amenable to mammalian NER is relatively small (8-10 kDa) so that NER cannot participate in the repair of chromosomal DPCs in mammalian cells. Moreover, CLPs are not polyubiquitinated and hence are not subjected to proteasomal degradation prior to NER. In contrast, HR constitutes the major pathway in tolerance of DPCs as judged from cell survival and RAD51 and γ-H2AX nuclear foci formation. Induction of DPCs results in the accumulation of DNA double strand breaks in HR-deficient but not HR-proficient cells, suggesting that fork breakage at the DPC site initiates HR and reactivates the stalled fork. DPCs activate both ATR and ATMdamage response pathways, but there is a time lag between two responses. These results highlight the differential involvement of NER in the repair of DPCs in bacterial and mammalian cells and demonstrate the versatile and conserved role of HR in tolerance of DPCs among species.
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U2 - 10.1074/jbc.M109.019174
DO - 10.1074/jbc.M109.019174
M3 - Article
C2 - 19674975
AN - SCOPUS:70350446951
VL - 284
SP - 27065
EP - 27076
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 40
ER -