title: An alternative model of H ferritin promoter transactivation by c-Jun.
abstract: c-Jun is a member of the activator protein 1 family, and its interaction with different nuclear factors generates a wide spectrum of complexes that regulate transcription of different promoters. H ferritin promoter transcription is tightly dependent on nuclear factor Y (NFY). Ferritin transcription is activated by c-Jun, although the promoter does not contain a canonical binding site. NFY, on the other hand, does not bind c-Jun in vitro, whereas in vivo c-Jun is found in the complex containing NFY. Moreover, a c-Jun-GCN4 chimaeric construct containing only the transactivation domain of Jun and the basic-region leucine-zipper domain of GCN4 stimulates the H ferritin promoter. A synthetic GAL4 promoter and the cognate activator, the fusion protein NFY-GAL4, are potently activated by c-Jun. Titration of p300 by co-expressing E1A abolishes the stimulatory effect. Moreover, another p300-dependent promoter, the cAMP-response element, can be superactivated by c-Jun using the same mechanism. These data indicate that c-Jun, when activated or overexpressed, is recruited to the H ferritin promoter by p300, which links NFY, bound to DNA, to the complex. These results add a new level of complexity to transcriptional regulation by c-Jun, which can activate p300-dependent promoters without binding directly to the target DNA.
authors.affiliation: Dipartimento di Medicina Sperimentale e Clinica, Università degli Studi di Catanzaro, Via T. Campanella, I-88100 Catanzaro, Italy.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Faniello
authors.forename: Giuseppa
authors.initials: G
authors.lastname: Chirico
authors.forename: Barbara
authors.initials: B
authors.lastname: Quaresima
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cuda
authors.forename: Giovanna
authors.initials: G
authors.lastname: Allevato
authors.forename: Maria A
authors.initials: MA
authors.lastname: Bevilacqua
authors.forename: Francesco
authors.initials: F
authors.lastname: Baudi
authors.forename: Vittorio
authors.initials: V
authors.lastname: Colantuoni
authors.forename: Filiberto
authors.initials: F
authors.lastname: Cimino
authors.forename: Salvatore
authors.initials: S
authors.lastname: Venuta
authors.forename: Vittorio E
authors.initials: VE
authors.lastname: Avvedimento
authors.forename: Francesco
authors.initials: F
authors.lastname: Costanzo
mesh_terms: D001665:Binding Sites; D015153:Blotting, Western; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D005293:Ferritins / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D009687:Nuclear Proteins / Q000378:metabolism; D011233:Precipitin Tests; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D015534:Trans-Activators / Q000378:metabolism; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection
chemical_list: D009687:Nuclear Proteins; D016755:Proto-Oncogene Proteins c-jun; D011993:Recombinant Fusion Proteins; D011994:Recombinant Proteins; D015534:Trans-Activators; D005293:Ferritins; D000242:Cyclic AMP; D015500:Chloramphenicol O-Acetyltransferase