Dense Bicoid hubs accentuate binding along the morphogen gradient.
Genes Dev
; 31(17): 1784-1794, 2017 09 01.
Article
em En
| MEDLINE
| ID: mdl-28982761
ABSTRACT
Morphogen gradients direct the spatial patterning of developing embryos; however, the mechanisms by which these gradients are interpreted remain elusive. Here we used lattice light-sheet microscopy to perform in vivo single-molecule imaging in early Drosophila melanogaster embryos of the transcription factor Bicoid that forms a gradient and initiates patterning along the anteroposterior axis. In contrast to canonical models, we observed that Bicoid binds to DNA with a rapid off rate throughout the embryo such that its average occupancy at target loci is on-rate-dependent. We further observed Bicoid forming transient "hubs" of locally high density that facilitate binding as factor levels drop, including in the posterior, where we observed Bicoid binding despite vanishingly low protein levels. We propose that localized modulation of transcription factor on rates via clustering provides a general mechanism to facilitate binding to low-affinity targets and that this may be a prevalent feature of other developmental transcription factors.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Transativadores
/
Proteínas de Homeodomínio
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Proteínas de Drosophila
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Drosophila melanogaster
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Genes Dev
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Estados Unidos