title: An 8-oxo-guanine repair pathway coordinated by MUTYH glycosylase and DNA polymerase lambda.
abstract: Reactive oxygen species (ROS) interact with DNA, frequently generating highly mutagenic 7,8-dihydro-8-oxoguanine (8-oxo-G) lesions. Replicative DNA polymerases (pols) often misincorporate adenine opposite 8-oxo-G. The subsequent repair mechanism allowing the removal of adenine and formation of C:8-oxo-G base pair is essential to prevent C:G to A:T transversion mutations. Here, we show by immunofluorescence experiments, in cells exposed to ROS, the involvement of MutY glycosylase homologue (MUTYH) and DNA pol lambda in the repair of A:8-oxo-G mispairs. We observe specific recruitment of MUTYH, DNA pol lambda, proliferating cell nuclear antigen (PCNA), flap endonuclease 1 (FEN1) and DNA ligases I and III from human cell extracts to A:8-oxo-G DNA, but not to undamaged DNA. Using purified human proteins and a DNA template, we reconstitute the full pathway for the faithful repair of A:8-oxo-G mispairs involving MUTYH, DNA pol lambda, FEN1, and DNA ligase I. These results reveal a cellular response pathway to ROS, important to sustain genomic stability and modulate carcinogenesis.
authors.affiliation: Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
authors.forename: Barbara
authors.initials: B
authors.lastname: van Loon
authors.forename: Ulrich
authors.initials: U
authors.lastname: Hübscher
mesh_terms: D004249:DNA Damage; D045647:DNA Glycosylases / Q000235:genetics / Q000378:metabolism*; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000378:metabolism; D019951:DNA Polymerase beta / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair; D004261:DNA Replication; D042822:Genomic Instability; D006147:Guanine / Q000031:analogs & derivatives* / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D016296:Mutagenesis; D010084:Oxidation-Reduction; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D011485:Protein Binding; D017382:Reactive Oxygen Species / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: C453560:7,8-dihydro-8-oxoguanine; C000607892:LIG1 protein, human; D018809:Proliferating Cell Nuclear Antigen; D017382:Reactive Oxygen Species; D006147:Guanine; C415367:DNA polymerase beta2; D019951:DNA Polymerase beta; D045647:DNA Glycosylases; C061738:mutY adenine glycosylase; D011088:DNA Ligases; D000072481:DNA Ligase ATP