Year: 2017
Type: article
Abstract: ALC1/CHD1L is a member of the SNF2 superfamily of ATPases carrying a macrodomain that binds poly(ADP-ribose). Poly(ADP-ribose) polymerase (PARP) 1 and 2 synthesize poly(ADP-ribose) at DNA-strand cleavage sites, promoting base excision repair (BER). Although depletion of ALC1 causes increased sensitivity to various DNA-damaging agents (H2O2, UV, and phleomycin), the role played by ALC1 in BER has not yet been established. To explore this role, as well as the role of ALC1's ATPase activity in BER, we disrupted the ALC1 gene and inserted the ATPase-dead (E165Q) mutation into the ALC1 gene in chicken DT40 cells, which do not express PARP2. The resulting ALC1-/- and ALC1-/E165Q cells displayed an indistinguishable hypersensitivity to methylmethane sulfonate (MMS), an alkylating agent, and to H2O2, indicating that ATPase plays an essential role in the DNA-damage response. PARP1-/- and ALC1-/-/PARP1-/- cells exhibited a very similar sensitivity to MMS, suggesting that ALC1 and PARP1 collaborate in BER. Following pulse-exposure to H2O2, PARP1-/- and ALC1-/-/PARP1-/- cells showed similarly delayed kinetics in the repair of single-strand breaks, which arise as BER intermediates. To ascertain ALC1's role in BER in mammalian cells, we disrupted the ALC1 gene in human TK6 cells. Following exposure to MMS and to H2O2, the ALC1-/- TK6 cell line showed a delay in single-strand-break repair. We therefore conclude that ALC1 plays a role in BER. Following exposure to H2O2, ALC1-/- cells showed compromised chromatin relaxation. We thus propose that ALC1 is a unique BER factor that functions in a chromatin context, most likely as a chromatin-remodeling enzyme.
Source: PLoS ONE
Authors: Masataka Tsuda, Kosai Cho, Masato Ooka, Naoto Shimizu, Reiko Watanabe, Akira Yasui, Yuka Nakazawa, Tomoo Ogi, Hiroshi Harada, Keli Agama, Jun Nakamura, Ryuta Asada, Haruna Fujiike, Tetsushi Sakuma, Takashi Yamamoto, Junko Murai, Masahiro Hiraoka, Kaoru Koike, Yves Pommier, Shunichi Takeda, Kouji Hirota
Institutions: Kyoto University, Tokyo Metropolitan University, Tohoku University, Nagasaki University, Nagoya University, National Institutes of Health, National Cancer Institute, Center for Cancer Research, University of North Carolina at Chapel Hill, Hiroshima University, Japanese Red Cross Society Wakayama Medical Center
Language: English
Topic: DNA Repair Mechanisms
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,382
Awards: G1298195085, G2495002360, DNA double strand break repair factors mutated in a new syndrome with microcephaly, Molecular pathogenesis of human genetic disorders associated with deficiency in the DNA repair and damage response system, G3468040176, Analysis of a new genetic disorder caused by the deficiency in radiation-induced DNA double-strand break repair, Establishment of Novel Bioassays for in vivo Genotoxicity Prediction and Mechanism Characterization, Development of disease-modeling technology using hierarchical genome/epigenome editing, DNA Repair, Cell Cycle Checkpoints and Apoptosis as Targets for Anticancer Drugs, Analysis of the regulatory network of polymerases upon replication arrest, Analysis of Translesion synthesis (TLS) mechanism by novel assay method, 分裂酵母ｆｂｐ１におけるゲノム三次元構造を利用した遺伝子発現精密制御機構の解明, G9000173957
OpenAlex ID: W2768129283