title: The proapoptotic gene SIVA is a direct transcriptional target for the tumor suppressors p53 and E2F1.
abstract: The p53 tumor suppressor gene is believed to play an important role in neuronal cell death in acute neurological disease and in neurodegeneration. The p53 signaling cascade is complex, and the mechanism by which p53 induces apoptosis is cell type-dependent. Using DNA microarray analysis, we have found a striking induction of the proapoptotic gene, SIVA. SIVA is a proapoptotic protein containing a death domain and interacts with members of the tumor necrosis factor receptor family as well as anti-apoptotic Bcl-2 family proteins. SIVA is induced following direct p53 gene delivery, treatment with a DNA-damaging agent camptothecin, and stroke injury in vivo. SIVA up-regulation is sufficient to initiate the apoptotic cascade in neurons. Through isolation and analysis of the SIVA promoter, we have identified response elements for both p53 and E2F1. Like p53, E2F1 is another tumor suppressor gene involved in the regulation of apoptosis, including neuronal injury models. We have identified E2F consensus sites in the promoter region, whereas p53 recognition sequences were found in intron1. Sequence analysis has shown that these consensus sites are also conserved between mouse and human SIVA genes. Electrophoretic mobility shift assays reveal that both transcription factors are capable of binding to putative consensus sites, and luciferase reporter assays reveal that E2F1 and p53 can activate transcription from the SIVA promoter. Here, we report that the proapoptotic gene, SIVA, which functions in a broad spectrum of cell types, is a direct transcriptional target for both tumor suppressors, p53 and E2F1.
authors.affiliation: Ottawa Health Research Institute, Neuroscience Centre and Department of Cellular and Molecular Medicine, University of Ottawa, 451 Smyth Road, Ottawa, Ontario K1H 8M5, Canada.
authors.forename: Andre
authors.initials: A
authors.lastname: Fortin
authors.forename: Jason G
authors.initials: JG
authors.lastname: MacLaurin
authors.forename: Nicole
authors.initials: N
authors.lastname: Arbour
authors.forename: Sean P
authors.initials: SP
authors.lastname: Cregan
authors.forename: Neena
authors.initials: N
authors.lastname: Kushwaha
authors.forename: Steven M
authors.initials: SM
authors.lastname: Callaghan
authors.forename: David S
authors.initials: DS
authors.lastname: Park
authors.forename: Paul R
authors.initials: PR
authors.lastname: Albert
authors.forename: Ruth S
authors.initials: RS
authors.lastname: Slack
mesh_terms: D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D017209:Apoptosis; D051017:Apoptosis Regulatory Proteins; D001483:Base Sequence; D001665:Binding Sites; D015153:Blotting, Western; D002166:Camptothecin / Q000494:pharmacology; D002352:Carrier Proteins / Q000096:biosynthesis* / Q000235:genetics*; D018797:Cell Cycle Proteins; D002478:Cells, Cultured; D004249:DNA Damage; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D017930:Genes, Reporter; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008156:Luciferases / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014157:Transcription Factors / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D015854:Up-Regulation
chemical_list: D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; C493754:E2f1 protein, mouse; D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger; C106549:SIVA1 protein, human; C484569:Siva protein, mouse; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D012313:RNA; D008156:Luciferases; D002166:Camptothecin