title: Ultraviolet irradiation and c-jun over-expression regulates replication of polyoma sequences in WOP cells through a PEBP2 binding site.
abstract: Mouse fibroblast cells (WOP) express permissive factors which support polyoma DNA replication. However, electroporation into WOP cells of a mammalian expression vector that encodes the c-jun cDNA results in repression of polyoma DNA replication in a dose-dependent manner. In previous studies we have shown that UV-irradiation is capable of mediating a similar effect on polyoma DNA replication. When c-jun over-expression was combined with ultraviolet (UV)-irradiation, polyoma DNA replication decreased further. The repression of replication mediated by c-jun appears to be mediated by factor(s) that bind to PEBP4/2 target sequences as oligomers bearing the PEBP2/4 target site were capable of restoring polyoma DNA replication when added to UV-treated or c-jun over-expressing cells. The binding to the PEBP2/4 is partially dependent on the availability of AP-1 proteins, since an AP-1 target sequence can efficiently compete one of the three complexes formed with the PEBP2 target site. PEPB2 sequences do not, however, affect binding to the AP1 site. The effect of PEBP2 on polyoma replication is not dependent on the adjacent AP-1 site since PEBP2 could restore replication of polyomavirus which is mutated at the AP-1 sequence. A similar replication pattern was noted in a deletion mutant of polyoma which lacks PEBP4, yet, contains an intact PEBP2 binding sequence, suggesting that PEBP2 is the principle target for mediating repression of polyoma DNA replication.
authors.affiliation: Molecular Carcinogenesis Program, American Health Foundation, Valhalla, NY 10595.
authors.forename: S E
authors.initials: SE
authors.lastname: Rutberg
authors.forename: S Y
authors.initials: SY
authors.lastname: Fuchs
authors.forename: Z
authors.initials: Z
authors.lastname: Ronai
mesh_terms: D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D050659:Core Binding Factor Alpha 1 Subunit; D050658:Core Binding Factor beta Subunit; D004261:DNA Replication; D004279:DNA, Viral / Q000096:biosynthesis* / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism / Q000528:radiation effects* / Q000821:virology; D005786:Gene Expression Regulation / Q000528:radiation effects*; D015967:Gene Expression Regulation, Viral / Q000528:radiation effects; D051379:Mice; D008969:Molecular Sequence Data; D011120:Polyomavirus / Q000235:genetics / Q000502:physiology*; D016755:Proto-Oncogene Proteins c-jun / Q000096:biosynthesis* / Q000235:genetics; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D050656:Transcription Factor AP-2; D014157:Transcription Factors / Q000378:metabolism*; D014466:Ultraviolet Rays; D014779:Virus Replication
chemical_list: C493693:Cbfb protein, mouse; D050659:Core Binding Factor Alpha 1 Subunit; D050658:Core Binding Factor beta Subunit; D004279:DNA, Viral; D004268:DNA-Binding Proteins; D016755:Proto-Oncogene Proteins c-jun; C493716:Runx2 protein, mouse; D018808:Transcription Factor AP-1; D050656:Transcription Factor AP-2; D014157:Transcription Factors; C055473:enhancer-binding protein AP-4