title: Identification of nuclear proteins that interact with platinum-modified DNA by photoaffinity labeling.
abstract: Interactions between cellular proteins and cisplatin-modified DNA are important in determining the anticancer activity of the drug. To develop a general approach for identifying proteins that mediate cellular responses to cisplatin, photoreactive cisplatin analogues having a tethered benzophenone moiety were prepared and used to form the major 1,2-intrastrand platinum-DNA cross-links. Upon irradiation of the platinated DNA dissolved in a HeLa nuclear extract, the appended photolabile benzophenone group generates a highly reactive species that binds irreversibly to cellular proteins that interact with the probe. Several DNA-protein cross-linked adducts were identified that may function in the cellular processing of cisplatin-DNA adducts. Of these, PARP-1 had not previously been demonstrated directly to contact Pt-DNA cross-links in human cells.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Christiana Xin
authors.initials: CX
authors.lastname: Zhang
authors.forename: Pamela V
authors.initials: PV
authors.lastname: Chang
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Lippard
mesh_terms: D001483:Base Sequence; D001577:Benzophenones / Q000737:chemistry; D002945:Cisplatin / Q000031:analogs & derivatives* / Q000378:metabolism*; D003432:Cross-Linking Reagents / Q000737:chemistry; D004247:DNA / Q000187:drug effects / Q000378:metabolism*; D018736:DNA Adducts / Q000378:metabolism*; D024243:HMGB1 Protein / Q000737:chemistry / Q000378:metabolism*; D024261:HMGB2 Protein / Q000737:chemistry / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D009841:Oligonucleotides / Q000737:chemistry; D019920:Photoaffinity Labels; D010777:Photochemistry; D017319:Photosensitizing Agents / Q000737:chemistry; D011065:Poly(ADP-ribose) Polymerases / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001577:Benzophenones; D003432:Cross-Linking Reagents; D018736:DNA Adducts; D024243:HMGB1 Protein; D024261:HMGB2 Protein; D009841:Oligonucleotides; D019920:Photoaffinity Labels; D017319:Photosensitizing Agents; C057270:cisplatin-DNA adduct; C047723:benzophenone; D004247:DNA; D011065:Poly(ADP-ribose) Polymerases; D002945:Cisplatin