TY - DATA T1 - DNA end resection is needed for the repair of complex lesions in G1-phase human cells PY - 2015/10/09 AU - Nicole B Averbeck AU - Oliver Ringel AU - Maren Herrlitz AU - Burkhard Jakob AU - Marco Durante AU - Gisela Taucher-Scholz UR - https://tandf.figshare.com/articles/dataset/DNA_end_resection_is_needed_for_the_repair_of_complex_lesions_in_G1_phase_human_cells/1246749 DO - 10.6084/m9.figshare.1246749.v2 L4 - https://ndownloader.figshare.com/files/1800796 L4 - https://ndownloader.figshare.com/files/1800797 L4 - https://ndownloader.figshare.com/files/1800798 L4 - https://ndownloader.figshare.com/files/1800799 L4 - https://ndownloader.figshare.com/files/1800800 L4 - https://ndownloader.figshare.com/files/1800801 L4 - https://ndownloader.figshare.com/files/1800802 L4 - https://ndownloader.figshare.com/files/3247103 KW - lesion complexity KW - RPA KW - exo KW - Ku heterodimer KW - DNA lesions KW - mre KW - hr KW - Clustered lesions KW - genotoxic agents KW - chemical complexity KW - replication protein KW - meiotic recombination 11 homolog KW - cells ABSTRACTRepair KW - atr KW - cells resection KW - DNA resection KW - exonuclease 1 KW - cytotoxic agents KW - DSB resection KW - strand breaks KW - CtIP depletion KW - DNA end resection KW - process sensitizes KW - H 2AX Reduced resection capacity KW - Ataxia telangiectasia KW - unrepaired DSBs KW - cell cycle N2 - ABSTRACTRepair of DNA double strand breaks (DSBs) is influenced by the chemical complexity of the lesion. Clustered lesions (complex DSBs) are generally considered more difficult to repair and responsible for early and late cellular effects after exposure to genotoxic agents. Resection is commonly used by the cells as part of the homologous recombination (HR) pathway in S- and G2-phase. In contrast, DNA resection in G1-phase may lead to an error-prone microhomology-mediated end joining. We induced DNA lesions with a wide range of complexity by irradiation of mammalian cells with X-rays or accelerated ions of different velocity and mass. We found replication protein A (RPA) foci indicating DSB resection both in S/G2- and G1-cells, and the fraction of resection-positive cells correlates with the severity of lesion complexity throughout the cell cycle. Besides RPA, Ataxia telangiectasia and Rad3-related (ATR) was recruited to complex DSBs both in S/G2- and G1-cells. Resection of complex DSBs is driven by meiotic recombination 11 homolog A (MRE11), CTBP-interacting protein (CtIP), and exonuclease 1 (EXO1) but seems not controlled by the Ku heterodimer or by phosphorylation of H2AX. Reduced resection capacity by CtIP depletion increased cell killing and the fraction of unrepaired DSBs after exposure to densely ionizing heavy ions, but not to X-rays. We conclude that in mammalian cells resection is essential for repair of complex DSBs in all phases of the cell-cycle and targeting this process sensitizes mammalian cells to cytotoxic agents inducing clustered breaks, such as in heavy-ion cancer therapy. ER -