Transcriptional control: rheostat converted to on/off switch.
Mol Cell
; 6(3): 723-8, 2000 Sep.
Article
em En
| MEDLINE
| ID: mdl-11030351
ABSTRACT
Individual cells translate concentration gradients of extracellular factors into all-or-none threshold responses leading to discrete patterns of gene expression. Signaling cascades account for some but not all such threshold responses, suggesting the existence of additional mechanisms. Here we show that all-or-none responses can be generated at a transcriptional level. A graded rheostat mechanism obtained when either transactivators or transrepressors are present is converted to an on/off switch when these factors compete for the same DNA regulatory element. Hill coefficients of dose-response curves confirm that the synergistic responses generated by each factor alone are additive, obviating the need for feedback loops. We postulate that regulatory networks of competing transcription factors prevalent in cells and organisms are crucial for establishing true molecular on/off switches.
Buscar no Google
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Ativação Transcricional
/
Regiões Promotoras Genéticas
/
Biologia Molecular
Idioma:
En
Revista:
Mol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Estados Unidos