Sensing and Processing of DNA Interstrand Crosslinks by the Mismatch Repair Pathway
Niyo Kato,
Yoshitaka Kawasoe,
Hannah Williams,
Elena Coates,
Upasana Roy,
Yuqian Shi,
Lorena S. Beese,
Orlando D. Schärer,
Hong Yan,
Max E. Gottesman,
Tatsuro S. Takahashi,
Jean Gautier
Affiliations
Niyo Kato
Institute of Cancer Genetics, Columbia University, New York, NY 10032, USA
Yoshitaka Kawasoe
Graduate School of Science, Osaka University, Toyonaka, Japan
Hannah Williams
Institute of Cancer Genetics, Columbia University, New York, NY 10032, USA
Elena Coates
Institute of Cancer Genetics, Columbia University, New York, NY 10032, USA
Upasana Roy
Department of Chemistry and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA
Yuqian Shi
Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
Lorena S. Beese
Department of Biochemistry, Duke University Medical Center, Durham, NC 27710, USA
Orlando D. Schärer
Department of Chemistry and Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794, USA; Institute for Basic Science Center for Genomic Integrity and School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan, South Korea
Hong Yan
Fox Chase Cancer Center, Philadelphia, PA 19111, USA
Max E. Gottesman
Institute of Cancer Research, Columbia University, New York, NY 10032, USA
Tatsuro S. Takahashi
Department of Biology, Kyushu University, Fukuoka, Japan
Jean Gautier
Institute of Cancer Genetics, Columbia University, New York, NY 10032, USA; Corresponding author
Summary: DNA interstrand crosslinks (ICLs) that are repaired in non-dividing cells must be recognized independently of replication-associated DNA unwinding. Using cell-free extracts from Xenopus eggs that support neither replication nor transcription, we establish that ICLs are recognized and processed by the mismatch repair (MMR) machinery. We find that ICL repair requires MutSα (MSH2–MSH6) and the mismatch recognition FXE motif in MSH6, strongly suggesting that MutSα functions as an ICL sensor. MutSα recruits MutLα and EXO1 to ICL lesions, and the catalytic activity of both these nucleases is essential for ICL repair. As anticipated for a DNA unwinding-independent recognition process, we demonstrate that least distorting ICLs fail to be recognized and repaired by the MMR machinery. This establishes that ICL structure is a critical determinant of repair efficiency outside of DNA replication. : Kato et al. identify a mechanism of ICL recognition that operates independently of DNA replication and transcription. In the absence of these processes, ICLs are recognized and repaired by the MMR machinery. MutSα is critical for ICL recognition, while MutLα and EXO1 contribute to key downstream nucleolytic steps during ICL repair. Keywords: mismatch repair, interstrand crosslink, replication-independent repair, Xenopus
