title: Immortalization of human cells by mutant and chimeric primate polyomavirus T-antigen genes.
abstract: Human fibroblasts were morphologically transformed with wild type and mutant SV40 T-antigens (T-Ags) and with SV40/JCV and SV40/BKV chimeric T-Ags. The transformants were then assayed for the attainment of immortal cell growth. Several observations relating T-Ag and T-Ag domains to immortalization were made. Approximately 10% of SV40-transformants became immortal. Transformants generated by transfection or infection of cells with C-terminal T-Ag deletion mutants of SV40 did not immortalize. SV40/JCV and SV40/BKV chimeric T-Ags, containing C-terminal sequences from JCV or BKV, immortalized cells more efficiently than did the intact SV40 T-Ag, suggesting that the C-termini of the JCV and BKV T-Ags contain an enhanced immortalization function. However, chimeras in which the N-terminal or proximal-central portions of T-Ag were composed of JCV sequences failed to immortalize but did induce transformation. Constructs in which the JCV T-Ag Rb binding domain was replaced with SV40 sequences transformed human cells, but again the cells failed to immortalize. Transformants and immortalized cell lines produced by some SV40/JCV chimeras, contained p53 which was unbound by T-Ag. This occurred under conditions where p53 from SV40 and SV40/BKV transformants was bound to T-Ag. This may reflect the reduced stability of the SV40/JCV T-Ags.
authors.affiliation: Department of Veterans Affairs Research Service, Salt Lake City, Utah 84148.
authors.forename: F J
authors.initials: FJ
authors.lastname: O'Neill
authors.forename: R J
authors.initials: RJ
authors.lastname: Frisque
authors.forename: X
authors.initials: X
authors.lastname: Xu
authors.forename: Y X
authors.initials: YX
authors.lastname: Hu
authors.forename: H
authors.initials: H
authors.lastname: Carney
mesh_terms: D000952:Antigens, Polyomavirus Transforming / Q000235:genetics*; D015139:Blotting, Southern; D002472:Cell Transformation, Viral / Q000235:genetics*; D002478:Cells, Cultured; D004279:DNA, Viral; D005347:Fibroblasts; D006801:Humans; D009154:Mutation; D011993:Recombinant Fusion Proteins / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D000952:Antigens, Polyomavirus Transforming; D004279:DNA, Viral; D011993:Recombinant Fusion Proteins; D016159:Tumor Suppressor Protein p53