Résumé
The core promoter is an important yet often overlooked component in the regulation of transcription by RNA polymerase II. In fact, the core promoter is the ultimate target of action of all of the factors and coregulators that control the transcriptional activity of every gene. In this review, I describe our current knowledge of a downstream core promoter element termed the DPE, which is a TFIID recognition site that is conserved from Drosophila to humans. The DPE is located from +28 to +32 relative to the +1 transcription start site, and is mainly present in core promoters that lack a TATA box motif. Moreover, in Drosophila, the DPE appears to be about as common as the TATA box. There are distinct mechanisms of basal transcription from DPE- versus TATA-dependent core promoters. For instance, NC2/Dr1-Drap1 is a repressor of TATA-dependent transcription and an activator of DPE-dependent transcription. In addition, DPE-specific and TATA-specific transcriptional enhancers have been identified. These findings further indicate that the core promoter is an active participant in the regulation of eukaryotic gene expression.
Sujets)
Animaux , Humains , Séquence nucléotidique , Protéines de liaison à l'ADN/métabolisme , Éléments activateurs (génétique) , Rétrocontrôle physiologique , Régulation de l'expression des gènes , Modèles génétiques , Régions promotrices (génétique) , RNA polymerase II/métabolisme , Facteurs de transcription/composition chimique , Transcription génétiqueRésumé
The core promoter is an important yet often overlooked component in the regulation of transcription by RNA polymerase II. In fact, the core promoter is the ultimate target of action of all of the factors and coregulators that control the transcriptional activity of every gene. In this review, I describe our current knowledge of a downstream core promoter element termed the DPE, which is a TFIID recognition site that is conserved from Drosophila to humans. The DPE is located from +28 to +32 relative to the +1 transcription start site, and is mainly present in core promoters that lack a TATA box motif. Moreover, in Drosophila, the DPE appears to be about as common as the TATA box. There are distinct mechanisms of basal transcription from DPE- versus TATA-dependent core promoters. For instance, NC2/Dr1-Drap1 is a repressor of TATA-dependent transcription and an activator of DPE-dependent transcription. In addition, DPE-specific and TATA-specific transcriptional enhancers have been identified. These findings further indicate that the core promoter is an active participant in the regulation of eukaryotic gene expression.