title: DNA methylation influences the decatenation activity of topoisomerase II.
abstract: Methylation of cytosine in CpG sequences of the DNA in mammalian cells is involved in the regulation of events like gene expression, genomic imprinting, transcription, and DNA replication. Changes in the DNA methylation pattern influence the DNA conformation. Therefore, certain proteins are disturbed in their interaction with DNA. In this paper, we investigate the influence on the decatenation activity of topoisomerase II, an essential enzyme that modulates DNA topology. We compare the decatenation activity of topoisomerase II for a mitochondrial parasite DNA, that we had methylated to different degrees, and found the decatenation to be methylation dependent. Thus, changes in the methylation pattern are a mechanism for the disturbance of certain topoisomerase II activities and may, therefore, be an event in topoisomerase II related mutagenicity and carcinogenicity.
authors.affiliation: Department of Toxicology, University of Würzburg, Verbacher Strasse 9, 97078, Würzburg, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Boos
authors.forename: H
authors.initials: H
authors.lastname: Stopper
mesh_terms: D000818:Animals; D018899:CpG Islands; D016831:Crithidia fasciculata / Q000235:genetics; D003596:Cytosine / Q000378:metabolism; D019175:DNA Methylation; D004250:DNA Topoisomerases, Type II / Q000378:metabolism*; D004272:DNA, Mitochondrial / Q000378:metabolism; D004587:Electrophoresis, Agar Gel; D016296:Mutagenesis; D009369:Neoplasms / Q000235:genetics; D009690:Nucleic Acid Conformation
chemical_list: D004272:DNA, Mitochondrial; D003596:Cytosine; D004250:DNA Topoisomerases, Type II