title: Characterization of p53 expression in rainbow trout.
abstract: The tumour suppressor protein p53 is a critical component of cell cycle checkpoint responses. It upregulates the expression of cyclin-dependent kinase inhibitors in response to DNA damage and other cellular perturbations, and promotes apoptosis when DNA repair pathways are overwhelmed. Given the high incidence of p53 mutations in human cancers, it has been extensively studied, though only a small fraction of these investigations have been in non-mammalian systems. For the present study, an anti-rainbow trout p53 polyclonal antibody was generated. A variety of rainbow trout (Oncorhynchus mykiss) tissues and cell lines were examined through western blot analysis of cellular protein extracts, which revealed relatively high p53 levels in brain and gills. To evaluate the checkpoint response of rainbow trout p53, RTbrain-W1 and RTgill-W1 cell lines were exposed to varying concentrations of the DNA damaging agent bleomycin and ribonucleotide reductase inhibitor hydroxyurea. In contrast to mammals, these checkpoint-inducing agents provoked no apparent increase in rainbow trout p53 levels. These results infer the presence of alternate DNA damage checkpoint mechanisms in rainbow trout cells.
authors.affiliation: Department of Biology, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada.
authors.forename: Michelle
authors.initials: M
authors.lastname: Liu
authors.forename: Catherine
authors.initials: C
authors.lastname: Tee
authors.forename: Fanxing
authors.initials: F
authors.lastname: Zeng
authors.forename: James P
authors.initials: JP
authors.lastname: Sherry
authors.forename: Brian
authors.initials: B
authors.lastname: Dixon
authors.forename: Niels C
authors.initials: NC
authors.lastname: Bols
authors.forename: Bernard P
authors.initials: BP
authors.lastname: Duncker
mesh_terms: D000818:Animals; D001761:Bleomycin / Q000494:pharmacology; D001921:Brain / Q000378:metabolism; D059447:Cell Cycle Checkpoints / Q000187:drug effects; D002460:Cell Line; D004249:DNA Damage; D015870:Gene Expression; D005880:Gills / Q000378:metabolism; D006918:Hydroxyurea / Q000494:pharmacology; D017686:Oncorhynchus mykiss / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis*
chemical_list: D016159:Tumor Suppressor Protein p53; D001761:Bleomycin; D006918:Hydroxyurea