title: Effect of anti-cruciform DNA monoclonal antibodies on DNA replication.
abstract: To study the possible involvement of DNA cruciforms in the initiation of DNA replication, we used two monoclonal antibodies, 2D3 and 4B4, with anti-cruciform DNA specificity. Synchronized CV-1 cells were released into S phase for hourly intervals up to 6 h and permeabilized in the presence of monoclonal antibodies, under conditions that allow limited DNA replication. Exposure of the permeabilized cells to 2D3 or 4B4 resulted in a 2- to 6-fold enhancement of incorporation of labeled precursor nucleotide over the 6 h period. Approximately 50% of the enhanced synthesis was sensitive to aphidicolin, and the enhancing effect of 2D3 was abolished by absorption with immunobead anti-mouse immunoglobulin. Dot-blot hybridization analyses of DNA isolated from anti-cruciform antibody treatment groups showed a similar 2- to 11-fold increase in the relative copy number of low copy probes. In contrast, exposure of the permeabilized cells to a monoclonal antibody directed against Z-DNA and B-DNA had no significant effect on DNA synthesis. The results suggest that cruciforms are present in replicating DNA and that they are recognized and stabilized by the monoclonal antibodies.
authors.affiliation: McGill Cancer Centre, McGill University, Montreal, Quebec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Zannis-Hadjopoulos
authors.forename: L
authors.initials: L
authors.lastname: Frappier
authors.forename: M
authors.initials: M
authors.lastname: Khoury
authors.forename: G B
authors.initials: GB
authors.lastname: Price
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D002460:Cell Line; D002522:Chlorocebus aethiops; D004247:DNA / Q000276:immunology; D004261:DNA Replication; D009690:Nucleic Acid Conformation; D012091:Repetitive Sequences, Nucleic Acid
chemical_list: D000911:Antibodies, Monoclonal; D004247:DNA