title: The two isoforms of the 90-kDalton nucleolus organizer region autoantigen (upstream binding factor) bind with different avidity to DNA modified by the antitumor drug cisplatin.
abstract: It has been previously described that some proteins containing HMG boxes are able to bind more strongly to DNA modified with cis-diamminedichloroplatinum (II) (cisplatin) than to unmodified DNA. In the present study, we analyzed the interaction of cisplatin-modified DNA with the human autoantigen NOR-90 (UBF), a transcription factor that contains several HMG boxes. Using autoantibodies against NOR-90 to perform ELISA and immunoprecipitation, it was confirmed that NOR-90 (UBF) was able to bind cisplatin-modified DNA more avidly than unmodified DNA or trans-diamminedichloroplatinum(II) (transplatin) modified DNA. Moreover, by Southwestern, we observed that the 97 kDalton isoform of NOR-90 (UBF1) was able to bind cisplatin-modified DNA more strongly than the 94 kDalton isoform (UBF2); binding of unmodified DNA or transplatin-modified DNA was not detected with either isoform. Sera containing autoantibodies against NOR-90 did not inhibit, but increased the binding of NOR-90 to cisplatin-modified DNA.
authors.affiliation: Department of Immunology, Hospital de Sant Pau, Universitat Autonoma de Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Codony-Servat
authors.forename: R
authors.initials: R
authors.lastname: Gimeno
authors.forename: C
authors.initials: C
authors.lastname: Gelpi
authors.forename: J L
authors.initials: JL
authors.lastname: Rodriguez-Sanchez
authors.forename: C
authors.initials: C
authors.lastname: Juarez
mesh_terms: D001324:Autoantigens / Q000378:metabolism*; D001665:Binding Sites; D002945:Cisplatin / Q000378:metabolism*; D018736:DNA Adducts / Q000378:metabolism*; D006801:Humans; D009687:Nuclear Proteins / Q000378:metabolism; D009697:Nucleolus Organizer Region / Q000276:immunology*
chemical_list: D001324:Autoantigens; D018736:DNA Adducts; D009687:Nuclear Proteins; C057270:cisplatin-DNA adduct; D002945:Cisplatin