Enhancement of transcription factor, USF, binding to the adenovirus major late promoter: effect of dithiothreitol and high mobility group protein-1.
Biochim Biophys Acta
; 1395(2): 228-36, 1998 Jan 21.
Article
en En
| MEDLINE
| ID: mdl-9473681
ABSTRACT
Up-stream stimulatory factor (USF)1 is a human transcription factor which binds specifically to the E-box in the Ad MLP located at - 58 from the start site. The nature of USF binding on a Ad MLP DNA fragment was investigated in the presence of DTT and also in the presence of purified HMG-1 using electrophoretic mobility shift assay. We show that the binding capacity of USF for the E-box increases significantly with increasing DTT concentrations. At the higher DTT levels, a second USF-DNA complex is formed in which there is co-occupation of both the E-box and the initiator sequence. The stability of the second complex is largely refractory to an excess of unlabeled oligonucleotide which contains the initiator sequence. These findings indicate a cooperative binding interaction between USF ligands bound simultaneously at the E-box and the Inr sequence. Two models are proposed which are consistent with these data. Furthermore, experiments indicate that the presence of HMG-1, a nuclear protein known to influence transcriptional activity, increases USF binding activity at the E-box by as much as 100%. These findings indicate that both reducing conditions and HMG-1 may act as modulators of USF-regulated transcription.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Factores de Transcripción
/
Proteínas del Grupo de Alta Movilidad
/
Adenoviridae
/
Regiones Promotoras Genéticas
/
Ditiotreitol
/
Proteínas de Unión al ADN
Tipo de estudio:
Prognostic_studies
Límite:
Humans
Idioma:
En
Revista:
Biochim Biophys Acta
Año:
1998
Tipo del documento:
Article
País de afiliación:
Estados Unidos