title: Expression of genes carried by pR plasmid in damaged E. coli and mouse cells.
abstract: In LTA mouse cells pR plasmid constitutively expresses itself resulting in protection against typical SOS inducers (UV, 4NQO) and in sensitization to different DNA-damaging agents (MNNG, cisDDP, BLM and geneticin (G418). The pR sensitizing effect is specific to mammalian cells, since the plasmid can only protect prokaryotic cells against the damaging agents tested. The pR protecting effect requires the expression of both the uvp1 and uvp2 (mucAB) regions in bacteria as well as in mouse cells. The coordinated function of these regions could result in protection against typical SOS inducers through an SOS/SOS-like pathway. The sensitization conferred by pR plasmid depends mostly on the expression of the mucAB genes, as shown by the survival of mouse cells transfected with different pR::Tn5 mutants. In particular, BLM and G418 survival data demonstrate that, inserted into the pR plasmid, the ble and neo genes of the Tn5 transposon express themselves. This was confirmed by the presence of Tn5 transcripts in untreated mouse cells. The comparison between the pR effects in bacterial and mouse cells shows that during evolution the repair pathways against UV damage are better conserved than those against other kinds of damage.
authors.affiliation: Dipartimento di Biopatologia Umana, Policlinico Umberto I, Università La Sapienza, Rome, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Marcucci
authors.forename: P
authors.initials: P
authors.lastname: Petrinelli
authors.forename: A
authors.initials: A
authors.lastname: Antonelli
authors.forename: R
authors.initials: R
authors.lastname: Elli
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000494:pharmacology; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D001761:Bleomycin / Q000494:pharmacology; D002460:Cell Line; D002945:Cisplatin / Q000494:pharmacology; D004249:DNA Damage; D004260:DNA Repair / Q000235:genetics*; D004251:DNA Transposable Elements / Q000235:genetics; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D029968:Escherichia coli Proteins; D015870:Gene Expression / Q000502:physiology*; D005839:Gentamicins / Q000494:pharmacology; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D051379:Mice; D016685:Mitomycin / Q000494:pharmacology; D009153:Mutagens / Q000494:pharmacology*; D010957:Plasmids / Q000235:genetics / Q000502:physiology*; D012333:RNA, Messenger / Q000032:analysis; D014158:Transcription, Genetic; D014466:Ultraviolet Rays
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D005839:Gentamicins; D009153:Mutagens; D012333:RNA, Messenger; D001761:Bleomycin; C061196:uvp1 protein, E coli; D008769:Methylnitronitrosoguanidine; C068606:mucAB protein, E coli; D016685:Mitomycin; D015112:4-Nitroquinoline-1-oxide; C010680:antibiotic G 418; D002945:Cisplatin