title: PCNA monoubiquitylation and DNA polymerase eta ubiquitin-binding domain are required to prevent 8-oxoguanine-induced mutagenesis in Saccharomyces cerevisiae.
abstract: 7,8-Dihydro-8-oxoguanine (8-oxoG) is an abundant and mutagenic DNA lesion. In Saccharomyces cerevisiae, the 8-oxoG DNA N-glycosylase (Ogg1) acts as the primary defense against 8-oxoG. Here, we present evidence for cooperation between Rad18-Rad6-dependent monoubiquitylation of PCNA at K164, the damage-tolerant DNA polymerase eta and the mismatch repair system (MMR) to prevent 8-oxoG-induced mutagenesis. Preventing PCNA modification at lysine 164 (pol30-K164R) results in a dramatic increase in GC to TA mutations due to endogenous 8-oxoG in Ogg1-deficient cells. In contrast, deletion of RAD5 or SIZ1 has little effect implying that the modification of PCNA relevant for preventing 8-oxoG-induced mutagenesis is monoubiquitin as opposed to polyubiquitin or SUMO. We also report that the ubiquitin-binding domain (UBZ) of Pol eta is essential to prevent 8-oxoG-induced mutagenesis but only in conjunction with a functional PCNA-binding domain (PIP). We propose that PCNA is ubiquitylated during the repair synthesis reaction after the MMR-dependent excision of adenine incorporated opposite to 8-oxoG. Monoubiquitylation of PCNA would favor the recruitment of Pol eta thereby allowing error-free incorporation of dCMP opposite to 8-oxoG. This study suggests that Pol eta and the post-replication repair (PRR) machinery can also prevent mutagenesis at DNA lesions that do not stall replication forks.
authors.affiliation: CEA, iRCM, UMR217 CNRS Radiobiologie Moléculaire et Cellulaire, 18 route du Panorama, BP6, 92265-Fontenay aux Roses, France.
authors.forename: Patricia Auffret
authors.initials: PA
authors.lastname: van der Kemp
authors.forename: Marcelo
authors.initials: M
authors.lastname: de Padula
authors.forename: Guenaelle
authors.initials: G
authors.lastname: Burguiere-Slezak
authors.forename: Helle D
authors.initials: HD
authors.lastname: Ulrich
authors.forename: Serge
authors.initials: S
authors.lastname: Boiteux
mesh_terms: D001665:Binding Sites; D002172:Canavanine / Q000494:pharmacology; D045647:DNA Glycosylases / Q000235:genetics / Q000378:metabolism; D004260:DNA Repair; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D006147:Guanine / Q000031:analogs & derivatives* / Q000378:metabolism; D016296:Mutagenesis; D009154:Mutation; D018809:Proliferating Cell Nuclear Antigen / Q000737:chemistry / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics; D025801:Ubiquitin / Q000378:metabolism; D054875:Ubiquitination; D000099270:Y-Family DNA Polymerases
chemical_list: D002172:Canavanine; D045647:DNA Glycosylases; D004259:DNA-Directed DNA Polymerase; D006147:Guanine; D018809:Proliferating Cell Nuclear Antigen; D029701:Saccharomyces cerevisiae Proteins; D025801:Ubiquitin; C522758:Pol32 protein, S cerevisiae; C024829:8-hydroxyguanine; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases; C505160:Ogg1 protein, S cerevisiae; C061738:mutY adenine glycosylase