title: Nucleotides with altered hydrogen bonding capacities impede human DNA polymerase η by reducing synthesis in the presence of the major cisplatin DNA adduct.
abstract: Human DNA polymerase η (hPol η) contributes to anticancer drug resistance by catalyzing the replicative bypass of DNA adducts formed by the widely used chemotherapeutic agent cis-diamminedichloroplatinum (cisplatin). A chemical basis for overcoming bypass-associated resistance requires greater knowledge of how small molecules influence the hPol η-catalyzed bypass of DNA adducts. In this study, we demonstrated how synthetic nucleoside triphosphates act as hPol η substrates and characterized their influence on hPol η-mediated DNA synthesis over unmodified and platinated DNA. The single nucleotide incorporation efficiency of the altered nucleotides varied by more than 10-fold and the higher incorporation rates appeared to be attributable to the presence of an additional hydrogen bond between incoming dNTP and templating base. Finally, full-length DNA synthesis in the presence of increasing concentrations of synthetic nucleotides reduced the amount of DNA product independent of the template, representing the first example of hPol η inhibition in the presence of a platinated DNA template.
authors.affiliation: §Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland.
authors.forename: Arman
authors.initials: A
authors.lastname: Nilforoushan
authors.affiliation: ‡Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Wintherthurerstrasse 190, 8057 Zürich, Switzerland.
authors.forename: Antonia
authors.initials: A
authors.lastname: Furrer
authors.affiliation: §Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Wyss
authors.affiliation: ‡Institute of Veterinary Biochemistry and Molecular Biology, University of Zurich, Wintherthurerstrasse 190, 8057 Zürich, Switzerland.
authors.forename: Barbara
authors.initials: B
authors.lastname: van Loon
authors.affiliation: §Department of Health Sciences and Technology, ETH Zürich, Schmelzbergstrasse 9, 8092 Zürich, Switzerland.
authors.forename: Shana J
authors.initials: SJ
authors.lastname: Sturla
mesh_terms: D001483:Base Sequence; D045744:Cell Line, Tumor; D002945:Cisplatin / Q000737:chemistry / Q000378:metabolism; D018736:DNA Adducts / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D006860:Hydrogen Bonding; D007700:Kinetics; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D019384:Nucleic Acid Synthesis Inhibitors / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D009711:Nucleotides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D011487:Protein Conformation; D000099270:Y-Family DNA Polymerases
chemical_list: D002945:Cisplatin; D018736:DNA Adducts; D004259:DNA-Directed DNA Polymerase; D019384:Nucleic Acid Synthesis Inhibitors; D009711:Nucleotides; C057270:cisplatin-DNA adduct; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases