title: HTLV type 1 Tax oncoprotein binds to DNA topoisomerase I and inhibits its catalytic activity.
abstract: HTLV-1 Tax oncoprotein exerts pleiotropic effects on cellular regulatory systems, trans-activation and trans-repression of transcription and promotion of the cell cycle, through interaction with various cellular factors. Here, we report Tax-mediated inhibition of DNA topoisomerase I. The interaction of Tax with topoisomerase I was demonstrated in vitro and also in vivo, and inhibition of DNA relaxation activity of topoisomerase I was clearly shown. These results suggested that Tax has a novel potential to affect various cellular processes, such as transcription and maintenance of genomic stability, in which DNA topoisomerase I is involved.
authors.affiliation: Department of Cellular and Molecular Biology, Institute of Medical Science, University of Tokyo, Tokyo, Japan. yoshimx@banyu.co.jp
authors.forename: M
authors.initials: M
authors.lastname: Yoshida
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D002461:Cell Line, Transformed; D004247:DNA / Q000378:metabolism; D004264:DNA Topoisomerases, Type I / Q000378:metabolism*; D016356:Gene Products, tax / Q000378:metabolism*; D015490:HTLV-I Infections / Q000821:virology; D015368:Human T-lymphotropic virus 1 / Q000378:metabolism*; D006801:Humans; D013601:T-Lymphocytes / Q000821:virology*; D059004:Topoisomerase I Inhibitors
chemical_list: D016356:Gene Products, tax; D059004:Topoisomerase I Inhibitors; D004247:DNA; D004264:DNA Topoisomerases, Type I