Delay in feedback repression by cryptochrome 1 is required for circadian clock function.
Cell
; 144(2): 268-81, 2011 Jan 21.
Article
em En
| MEDLINE
| ID: mdl-21236481
ABSTRACT
Direct evidence for the requirement of delay in feedback repression in the mammalian circadian clock has been elusive. Cryptochrome 1 (Cry1), an essential clock component, displays evening-time expression and serves as a strong repressor at morning-time elements (E box/E' box). In this study, we reveal that a combination of day-time elements (D box) within the Cry1-proximal promoter and night-time elements (RREs) within its intronic enhancer gives rise to evening-time expression. A synthetic composite promoter produced evening-time expression, which was further recapitulated by a simple phase-vector model. Of note, coordination of day-time with night-time elements can modulate the extent of phase delay. A genetic complementation assay in Cry1(-/-)Cry2(-/-) cells revealed that substantial delay of Cry1 expression is required to restore circadian rhythmicity, and its prolonged delay slows circadian oscillation. Taken together, our data suggest that phase delay in Cry1 transcription is required for mammalian clock function.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Retroalimentação
/
Criptocromos
/
Relógios Circadianos
Limite:
Animals
Idioma:
En
Revista:
Cell
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Japão