TY - JOUR
T1 - CHAMP1-POGZ counteracts the inhibitory effect of 53BP1 on homologous recombination and affects PARP inhibitor resistance
AU - Fujita, Hiroki
AU - Ikeda, Masanori
AU - Ui, Ayako
AU - Ouchi, Yunosuke
AU - Mikami, Yoshiko
AU - Kanno, Shin ichiro
AU - Yasui, Akira
AU - Tanaka, Kozo
N1 - Funding Information:
The authors thank Dr. H. Kurumizaka (The University of Tokyo) for an antibody against Rad51, Dr. M. Takata (Kyoto University) for U2OS cells stably expressing GFP-tagged CtIP, and Dr. T. Hirota (The Cancer Institute of Japanese Foundation for Cancer Research) for HeLa Kyoto cells. The authors also thank members of the K.T. laboratory for discussions, Y. Yoshizaki for his critical reading of the manuscript, and A. Harata for technical assistance. This work was supported by JSPS KAKENHI Grant Numbers 24370078, 24650616, 15H04368, 18H02434 and 17K19615; MEXT KAKENHI Grant Numbers 26116501, 16H01296, and 18H04896; and grants from the Takeda Science Foundation, Princess Takamatsu Cancer Research Fund (10-24210), and the Naito Foundation to K.T.
Funding Information:
The authors thank Dr. H. Kurumizaka (The University of Tokyo) for an antibody against Rad51, Dr. M. Takata (Kyoto University) for U2OS cells stably expressing GFP-tagged CtIP, and Dr. T. Hirota (The Cancer Institute of Japanese Foundation for Cancer Research) for HeLa Kyoto cells. The authors also thank members of the K.T. laboratory for discussions, Y. Yoshizaki for his critical reading of the manuscript, and A. Harata for technical assistance. This work was supported by JSPS KAKENHI Grant Numbers 24370078, 24650616, 15H04368, 18H02434 and 17K19615; MEXT KAKENHI Grant Numbers 26116501, 16H01296, and 18H04896; and grants from the Takeda Science Foundation, Princess Takamatsu Cancer Research Fund (10-24210), and the Naito Foundation to K.T.
Publisher Copyright:
© 2022, The Author(s), under exclusive licence to Springer Nature Limited.
PY - 2022/5/6
Y1 - 2022/5/6
N2 - DNA double-strand break (DSB) repair-pathway choice regulated by 53BP1 and BRCA1 contributes to genome stability. 53BP1 cooperates with the REV7-Shieldin complex and inhibits DNA end resection to block homologous recombination (HR) and affects the sensitivity to inhibitors for poly (ADP-ribose) polymerases (PARPs) in BRCA1-deficient cells. Here, we show that a REV7 binding protein, CHAMP1 (chromosome alignment-maintaining phosphoprotein 1), has an opposite function of REV7 in DSB repair and promotes HR through DNA end resection together with POGZ (POGO transposable element with ZNF domain). CHAMP1 was recruited to laser-micro-irradiation-induced DSB sites and promotes HR, but not NHEJ. CHAMP1 depletion suppressed the recruitment of BRCA1, but not the recruitment of 53BP1, suggesting that CHAMP1 regulates DSB repair pathway in favor of HR. Depletion of either CHAMP1 or POGZ impaired the recruitment of phosphorylated RPA2 and CtIP (CtBP-interacting protein) at DSB sites, implying that CHAMP1, in complex with POGZ, promotes DNA end resection for HR. Furthermore, loss of CHAMP1 and POGZ restored the sensitivity to a PARP inhibitor in cells depleted of 53BP1 together with BRCA1. These data suggest that CHAMP1and POGZ counteract the inhibitory effect of 53BP1 on HR by promoting DNA end resection and affect the resistance to PARP inhibitors.
AB - DNA double-strand break (DSB) repair-pathway choice regulated by 53BP1 and BRCA1 contributes to genome stability. 53BP1 cooperates with the REV7-Shieldin complex and inhibits DNA end resection to block homologous recombination (HR) and affects the sensitivity to inhibitors for poly (ADP-ribose) polymerases (PARPs) in BRCA1-deficient cells. Here, we show that a REV7 binding protein, CHAMP1 (chromosome alignment-maintaining phosphoprotein 1), has an opposite function of REV7 in DSB repair and promotes HR through DNA end resection together with POGZ (POGO transposable element with ZNF domain). CHAMP1 was recruited to laser-micro-irradiation-induced DSB sites and promotes HR, but not NHEJ. CHAMP1 depletion suppressed the recruitment of BRCA1, but not the recruitment of 53BP1, suggesting that CHAMP1 regulates DSB repair pathway in favor of HR. Depletion of either CHAMP1 or POGZ impaired the recruitment of phosphorylated RPA2 and CtIP (CtBP-interacting protein) at DSB sites, implying that CHAMP1, in complex with POGZ, promotes DNA end resection for HR. Furthermore, loss of CHAMP1 and POGZ restored the sensitivity to a PARP inhibitor in cells depleted of 53BP1 together with BRCA1. These data suggest that CHAMP1and POGZ counteract the inhibitory effect of 53BP1 on HR by promoting DNA end resection and affect the resistance to PARP inhibitors.
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UR - http://www.scopus.com/inward/citedby.url?scp=85127721476&partnerID=8YFLogxK
U2 - 10.1038/s41388-022-02299-6
DO - 10.1038/s41388-022-02299-6
M3 - Article
C2 - 35393543
AN - SCOPUS:85127721476
SN - 0950-9232
VL - 41
SP - 2706
EP - 2718
JO - Oncogene
JF - Oncogene
IS - 19
ER -
