TY - JOUR
T1 - DNA Repair Network Analysis Reveals Shieldin as a Key Regulator of NHEJ and PARP Inhibitor Sensitivity
AU - Gupta, Rajat
AU - Somyajit, Kumar
AU - Narita, Takeo
AU - Maskey, Elina
AU - Stanlie, Andre
AU - Kremer, Magdalena
AU - Typas, Dimitris
AU - Lammers, Michael
AU - Mailand, Niels
AU - Nussenzweig, Andre
AU - Lukas, Jiri
AU - Choudhary, Chunaram
N1 - Copyright © 2018 Elsevier Inc. All rights reserved.
PY - 2018/5/3
Y1 - 2018/5/3
N2 - Repair of damaged DNA is essential for maintaining genome integrity and for preventing genome-instability-associated diseases, such as cancer. By combining proximity labeling with quantitative mass spectrometry, we generated high-resolution interaction neighborhood maps of the endogenously expressed DNA repair factors 53BP1, BRCA1, and MDC1. Our spatially resolved interaction maps reveal rich network intricacies, identify shared and bait-specific interaction modules, and implicate previously concealed regulators in this process. We identified a novel vertebrate-specific protein complex, shieldin, comprising REV7 plus three previously uncharacterized proteins, RINN1 (CTC-534A2.2), RINN2 (FAM35A), and RINN3 (C20ORF196). Recruitment of shieldin to DSBs, via the ATM-RNF8-RNF168-53BP1-RIF1 axis, promotes NHEJ-dependent repair of intrachromosomal breaks, immunoglobulin class-switch recombination (CSR), and fusion of unprotected telomeres. Shieldin functions as a downstream effector of 53BP1-RIF1 in restraining DNA end resection and in sensitizing BRCA1-deficient cells to PARP inhibitors. These findings have implications for understanding cancer-associated PARPi resistance and the evolution of antibody CSR in higher vertebrates. Application of proximity-based quantitative proteomics allows the characterization of endogenous protein networks among major DNA damage repair factors and reveals the role of the protein complex shieldin in regulating NHEJ, antibody class switching, and sensitivity to PARP inhibitors.
AB - Repair of damaged DNA is essential for maintaining genome integrity and for preventing genome-instability-associated diseases, such as cancer. By combining proximity labeling with quantitative mass spectrometry, we generated high-resolution interaction neighborhood maps of the endogenously expressed DNA repair factors 53BP1, BRCA1, and MDC1. Our spatially resolved interaction maps reveal rich network intricacies, identify shared and bait-specific interaction modules, and implicate previously concealed regulators in this process. We identified a novel vertebrate-specific protein complex, shieldin, comprising REV7 plus three previously uncharacterized proteins, RINN1 (CTC-534A2.2), RINN2 (FAM35A), and RINN3 (C20ORF196). Recruitment of shieldin to DSBs, via the ATM-RNF8-RNF168-53BP1-RIF1 axis, promotes NHEJ-dependent repair of intrachromosomal breaks, immunoglobulin class-switch recombination (CSR), and fusion of unprotected telomeres. Shieldin functions as a downstream effector of 53BP1-RIF1 in restraining DNA end resection and in sensitizing BRCA1-deficient cells to PARP inhibitors. These findings have implications for understanding cancer-associated PARPi resistance and the evolution of antibody CSR in higher vertebrates. Application of proximity-based quantitative proteomics allows the characterization of endogenous protein networks among major DNA damage repair factors and reveals the role of the protein complex shieldin in regulating NHEJ, antibody class switching, and sensitivity to PARP inhibitors.
U2 - 10.1016/j.cell.2018.03.050
DO - 10.1016/j.cell.2018.03.050
M3 - Journal article
C2 - 29656893
SN - 0092-8674
VL - 173
SP - 972
EP - 988
JO - Cell
JF - Cell
IS - 4
ER -
