title: A tomato homologue of the human protein PIRIN is induced during programmed cell death.
abstract: Programmed cell death (PCD), with similarities to animal apoptosis, was induced in tomato suspension cells by the topoisomerase I inhibitor camptothecin. Previously, a differential display screening was performed to isolate genes differentially expressed during camptothecin-induced cell death. As a result, the new tomato gene Le-pirin was isolated, whose mRNA levels dramatically increase during camptothecin-induced PCD. Le-pirin mRNA accumulation is also observed when cell death is triggered by the mycotoxin fumonisin-B1, but not when the suspension cells are treated with stress-related compounds such as ethylene, methyl jasmonate or salicylic acid. The caspase inhibitor Z-Asp-CH2-DCB and the calcium channel blocker LaCl3 effectively delayed whereas ethylene greatly stimulated camptothecin-induced PCD and the accumulation of Le-pirin mRNA. The Le-pirin encoded protein shows 56% identity with the human protein PIRIN, a nuclear factor reported to interact with the human oncogene Bcl-3. Human PIRIN stabilizes the formation of quaternary complexes between Bcl-3, the anti-apoptotic transcription factor NF-kappaB and its DNA target sequences in vitro. The isolation of Le-pirin and its implication in plant PCD provides new clues on the role of putative NF-kappaB-associated pathways in plant defence mechanisms.
authors.affiliation: Agrotechnological Research institute (ATO), Wageningen University and Research Center, The Netherlands.
authors.forename: D
authors.initials: D
authors.lastname: Orzaez
authors.forename: A J
authors.initials: AJ
authors.lastname: de Jong
authors.forename: E J
authors.initials: EJ
authors.lastname: Woltering
mesh_terms: D000595:Amino Acid Sequence; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics*; D015139:Blotting, Southern; D002166:Camptothecin / Q000494:pharmacology; D002352:Carrier Proteins / Q000235:genetics*; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D049308:Dioxygenases; D018628:Gene Dosage; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D006801:Humans; D018551:Solanum lycopersicum / Q000166:cytology / Q000187:drug effects / Q000235:genetics*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics*; D018515:Plant Leaves / Q000235:genetics / Q000254:growth & development; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
chemical_list: D002352:Carrier Proteins; D018076:DNA, Complementary; D018744:DNA, Plant; D009687:Nuclear Proteins; D012333:RNA, Messenger; D049308:Dioxygenases; C105340:PIR protein, human; D002166:Camptothecin