Structural basis for distinct roles of SMAD2 and SMAD3 in FOXH1 pioneer-directed TGF-ß signaling.
Genes Dev
; 33(21-22): 1506-1524, 2019 11 01.
Article
en En
| MEDLINE
| ID: mdl-31582430
ABSTRACT
TGF-ß receptors phosphorylate SMAD2 and SMAD3 transcription factors, which then form heterotrimeric complexes with SMAD4 and cooperate with context-specific transcription factors to activate target genes. Here we provide biochemical and structural evidence showing that binding of SMAD2 to DNA depends on the conformation of the E3 insert, a structural element unique to SMAD2 and previously thought to render SMAD2 unable to bind DNA. Based on this finding, we further delineate TGF-ß signal transduction by defining distinct roles for SMAD2 and SMAD3 with the forkhead pioneer factor FOXH1 as a partner in the regulation of differentiation genes in mouse mesendoderm precursors. FOXH1 is prebound to target sites in these loci and recruits SMAD3 independently of TGF-ß signals, whereas SMAD2 remains predominantly cytoplasmic in the basal state and set to bind SMAD4 and join SMAD3FOXH1 at target promoters in response to Nodal TGF-ß signals. The results support a model in which signal-independent binding of SMAD3 and FOXH1 prime mesendoderm differentiation gene promoters for activation, and signal-driven SMAD2SMAD4 binds to promoters that are preloaded with SMAD3FOXH1 to activate transcription.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Transducción de Señal
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Modelos Moleculares
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Regulación de la Expresión Génica
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Factor de Crecimiento Transformador beta
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Proteína Smad2
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Proteína smad3
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Factores de Transcripción Forkhead
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Genes Dev
Asunto de la revista:
BIOLOGIA MOLECULAR
Año:
2019
Tipo del documento:
Article
País de afiliación:
España