B-Myb and cyclin D1 mediate heat shock element dependent activation of the human HSP70 promoter.
Oncogene
; 14(10): 1223-9, 1997 Mar 13.
Article
en En
| MEDLINE
| ID: mdl-9121772
ABSTRACT
Previous studies have shown that B-Myb, a conserved member of the Myb transcription factor family, is a potent activator of the promoter of the human HSP70 gene but does not activate promoters containing Myb binding sites. We have now investigated the transactivation properties of B-Myb in more detail. We here report that B-Myb activates the HSP70 promoter by a novel mechanism which involves the heat shock element (HSE). Deletion analysis of B-Myb shows that a specific domain in the center of B-Myb, but not the DNA-binding domain is required for HSE-dependent transactivation. We also show that deletion of the C-terminal domain of B-Myb does not affect HSE-dependent transactivation but allows the protein to activate a promoter containing Myb binding sites. This suggests that the ability to activate Myb binding site containing promoters is repressed in the context of full length B-Myb and that HSE dependent and Myb binding site dependent transactivation are distinct functions of B-Myb. Finally, we report that cyclin D1 like B-Myb strongly activates the HSP70 promoter via the HSE. HSE-dependent transactivation is a novel activity of cyclin D1 and appears to be independent of the phosphorylation of the Rb protein. Our results reveal an interesting and unexpected connection between HSE-dependent gene activation and proteins expressed during the G1/S-transition of the cell cycle.
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Base de datos:
MEDLINE
Asunto principal:
Factores de Transcripción
/
Activación Transcripcional
/
Regiones Promotoras Genéticas
/
Proteínas Oncogénicas
/
Ciclinas
/
Proteínas HSP70 de Choque Térmico
/
Proteínas de Unión al ADN
Límite:
Humans
Idioma:
En
Revista:
Oncogene
Asunto de la revista:
BIOLOGIA MOLECULAR
/
NEOPLASIAS
Año:
1997
Tipo del documento:
Article
País de afiliación:
Alemania