title: Repair of a DNA-protein crosslink by replication-coupled proteolysis.
abstract: DNA-protein crosslinks (DPCs) are caused by environmental, endogenous, and chemotherapeutic agents and pose a severe threat to genome stability. We use Xenopus egg extracts to recapitulate DPC repair in vitro and show that this process is coupled to DNA replication. A DPC on the leading strand template arrests the replisome by stalling the CMG helicase. The DPC is then degraded on DNA, yielding a peptide-DNA adduct that is bypassed by CMG. The leading strand subsequently resumes synthesis, stalls again at the adduct, and then progresses past the adduct using DNA polymerase ζ. A DPC on the lagging strand template only transiently stalls the replisome, but it too is degraded, allowing Okazaki fragment bypass. Our experiments describe a versatile, proteolysis-based mechanism of S phase DPC repair that avoids replication fork collapse.
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: Julien P
authors.initials: JP
authors.lastname: Duxin
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Dewar
authors.affiliation: Cancer Research UK, London Research Institute, Clare Hall Laboratories, South Mimms, Herts EN6 3LD, UK.
authors.forename: Hasan
authors.initials: H
authors.lastname: Yardimci
authors.affiliation: Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA; Howard Hughes Medical Institute. Electronic address: johannes_walter@hms.harvard.edu.
authors.forename: Johannes C
authors.initials: JC
authors.lastname: Walter
mesh_terms: D000818:Animals; D002457:Cell Extracts / Q000737:chemistry; D018736:DNA Adducts / Q000378:metabolism*; D004260:DNA Repair; D004261:DNA Replication; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D042822:Genomic Instability; D010063:Ovum / Q000737:chemistry; D014981:Xenopus
chemical_list: D002457:Cell Extracts; D018736:DNA Adducts; C425929:DNA polymerase zeta; D004259:DNA-Directed DNA Polymerase