SLX4–XPF mediates DNA damage responses to replication stress induced by DNA–protein interactions

• DOI: 10.1083/jcb.202003148
• Publication Date: 2020-12-21T16:36:55Z
• Authors: Riko Ishimoto; Yota Tsuzuki; Tomoki Matsumura; Seiichiro Kurashige; Kouki Enokitani; Koki Narimatsu; Mitsunori Higa; Nozomi Sugimoto; Kazumasa Yoshida; Masatoshi Fujita
• Keywords: DNA Replication; 0301 basic medicine; Fanconi Anemia Complementation Group D2 Protein; Ataxia Telangiectasia Mutated Proteins; DNA; Models, Biological; Article; S Phase; DNA-Binding Proteins; Recombinases; 03 medical and health sciences; Stress, Physiological; Cell Line, Tumor; Chromosome Segregation; Chromosomes, Human; Humans; Anaphase; DNA Damage; Protein Binding

The DNA damage response (DDR) has a critical role in the maintenance of genomic integrity during chromosome replication. However, responses to replication stress evoked by tight DNA–protein complexes have not been fully elucidated. Here, we used bacterial LacI protein binding to lacO arrays to make site-specific replication fork barriers on the human chromosome. These barriers induced the accumulation of single-stranded DNA (ssDNA) and various DDR proteins at the lacO site. SLX4–XPF functioned as an upstream factor for the accumulation of DDR proteins, and consequently, ATR and FANCD2 were interdependently recruited. Moreover, LacI binding in S phase caused underreplication and abnormal mitotic segregation of the lacO arrays. Finally, we show that the SLX4–ATR axis represses the anaphase abnormality induced by LacI binding. Our results outline a long-term process by which human cells manage nucleoprotein obstacles ahead of the replication fork to prevent chromosomal instability.