title: Identification of GATA2 and AP-1 Activator elements within the enhancer VNTR occurring in intron 5 of the human SIRT3 gene.
abstract: Human SIRT3 gene contains an intronic VNTR enhancer. A T > C transition occurring in the second repeat of each VNTR allele implies the presence/absence of a putative GATA binding motif. A partially overlapping AP-1 site, not affected by the transition, was also identified. Aims of the present study were: 1) to verify if GATA and AP-1 sites could bind GATA2 and c-Jun/c-Fos factors, respectively; 2) to investigate whether such sites modulate the enhancer activity of the SIRT3-VNTR alleles. DAPA assay proved that GATA2 and c-Jun/c-Fos factors are able to bind the corresponding sites. Moreover, co-transfection experiments showed that the over-expression of GATA2 and c-Jun/c-Fos factors boosts the VNTR enhancer activity in an allelic-specific way. Furthermore, we established that GATA2 and c-Jun/c-Fos act additively in modulating the SIRT3-VNTR enhancer function. Therefore, GATA2 and AP-1 are functional sites and the T S> C transition of the second VNTR repeat affects their activity.
authors.affiliation: Department of Cell Biology, University of Calabria, 87036, Rende, Italy. dina.bellizzi@unical.it
authors.forename: Dina
authors.initials: D
authors.lastname: Bellizzi
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Covello
authors.forename: Fausta
authors.initials: F
authors.lastname: Di Cianni
authors.forename: Qiang
authors.initials: Q
authors.lastname: Tong
authors.forename: Giovanna
authors.initials: G
authors.lastname: De Benedictis
mesh_terms: D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D004742:Enhancer Elements, Genetic / Q000235:genetics*; D050989:GATA2 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007438:Introns / Q000235:genetics; D018598:Minisatellite Repeats / Q000235:genetics; D017354:Point Mutation; D011485:Protein Binding; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism*; D016755:Proto-Oncogene Proteins c-jun / Q000235:genetics / Q000378:metabolism*; D056566:Sirtuin 3 / Q000235:genetics*; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism; D014162:Transfection
chemical_list: D050989:GATA2 Transcription Factor; C494711:GATA2 protein, human; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; C466093:SIRT3 protein, human; D056566:Sirtuin 3