B-Myb, a repressed trans-activating protein.
J Mol Med (Berl)
; 75(11-12): 815-9, 1997.
Article
en En
| MEDLINE
| ID: mdl-9428611
ABSTRACT
B-Myb belongs to a family of related transcription factors which share a unique DNA binding domain. B-Myb plays an important role in regulation of the cell cycle. Its expression is upregulated by the human papilloma virus HPV16 E7 oncoprotein. Overexpression of B-Myb can bypass p53-mediated cell cycle arrest. The founding member of the myb gene family, c-Myb, and A-Myb are involved in hematopoiesis and neurogenesis, respectively, and are both activators of gene transcription. Whether B-Myb is a transactivator or a repressor, however, has remained a matter of discussion. We reviewed the transactivation potential of B-Myb in yeast, taking advantage of the fact that inducible gene activation is an evolutionarily conserved process. By mutational analysis we localized a conserved activation domain in B-Myb. In vertebrate cells the transactivation potential of B-Myb is concealed by the C-terminal part of the protein. We show that the cell cycle regulators cyclin A and cyclin E activate B-Myb by eradicating the inhibition mediated by its carboxy-terminus. Our data suggest that in vertebrates the trans-activating function of B-Myb is regulated during the cell cycle and link Myb functions to cell cycle progression.
Search on Google
Banco de datos:
MEDLINE
Asunto principal:
Factores de Transcripción
/
Transactivadores
/
Proteínas de Ciclo Celular
/
Proteínas de Unión al ADN
Límite:
Animals
/
Humans
Idioma:
En
Año:
1997
Tipo del documento:
Article