A common mechanism underlying the E1A repression and the cAMP stimulation of the H ferritin transcription.
Transcription of the H ferritin gene in vivo is stimulated by cAMP and repressed by the E1A oncoprotein. We report here the identification of the cis-element in the human promoter responsive to both cAMP- and E1A-mediated signals. This promoter region is included between positions -62 to -45 and binds a approximate 120-kDa transcription factor called Bbf. Bbf forms a complex in vivo with the coactivator molecules p300 and CBP. Recombinant E1A protein reduces the formation of these complexes. In vivo overexpression of p300 in HeLa cells reverses the E1A-mediated inhibition of the ferritin promoter transcription driven by Bbf. These data suggest the existence of a common mechanism for the cAMP activation and the E1A-mediated repression of H ferritin transcription.
Bevilacqua
M A
MA
Dipartimento di Biochimica e Biotecnologie Mediche, Università degli Studi di Napoli "Federico II," Via S. Pansini 5, I-80131 Napoli, Italy.
Faniello
M C
MC
Quaresima
B
B
Tiano
M T
MT
Giuliano
P
P
Feliciello
A
A
Avvedimento
V E
VE
Cimino
F
F
Costanzo
F
F
D017500:Adenovirus E1A Proteins / Q000502:physiology*; D000242:Cyclic AMP / Q000502:physiology*; D017362:Cyclic AMP Response Element-Binding Protein / Q000502:physiology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology; D005293:Ferritins / Q000235:genetics*; D006367:HeLa Cells; D006801:Humans; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
D017500:Adenovirus E1A Proteins; D017362:Cyclic AMP Response Element-Binding Protein; D014157:Transcription Factors; D005293:Ferritins; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases