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

Abstract

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.

PHF8-promoted TOPBP1 demethylation drives ATR activation and preserves genome stability

“…S2B) (42). Subsequently, excess ssDNA is generated by structurespecific endonuclease and ATR pathway is activated at the stalled then possibly collapsed fork (43). Although expression of an mCherryLacI fusion protein resulted in a robust accumulation of ATRIP, RAD9, or TOPBP1 around the arrays in EdU (5Ethynyl2′deoxyuridine)positive cells, we did not observe evident arrayspecific accumulation of PHF8 (fig.…”

TRF2-mediated ORC recruitment underlies telomere stability upon DNA replication stress

“…Chromatin immunoprecipitation was performed as described previously ( 50 ). For qPCR analysis, SYBR Premix Ex Taq II (Takara, RR081A) or TB Green Premix Ex Taq II (Takara, RR820A) was used according to the manufacturer's instructions.…”

Fanconi anemia and dyskeratosis congenita/telomere biology disorders: Two inherited bone marrow failure syndromes with genomic instability

“…FANCP/SLX4 is a scaffolding protein that allows the engagement of multiple DNA endonucleases: MUS81, SLX1, and FANCQ/XPF/ERCC4 ( 26 , 27 ). FANCP/SLX4 is thought to be recruited by Ub-FANCD2-I, but recent reports have also shown that FANCP/SLX4 can directly recognize stalled replication forks and can be recruited to the site of damage independently from Ub-FANCD2 ( 28 , 29 ). The endonucleases coordinated by FANCP/SLX4 would cleave the phospho-backbone of the double stranded DNA, cut the DNA strand contiguous to the ICLs, and generate a DNA adduct and a DSB ( 30 ).…”