PUBLICATION

TALE factors poise promoters for activation by Hox proteins

Authors
Choe, S.K., Ladam, F., and Sagerström, C.G.
ID
ZDB-PUB-140404-8
Date
2014
Source
Developmental Cell   28(2): 203-211 (Journal)
Registered Authors
Choe, Seong-Kyu, Sagerström, Charles
Keywords
none
MeSH Terms
  • Animals
  • Blastula/metabolism
  • Gastrula/metabolism
  • Gene Expression Regulation, Developmental
  • Homeodomain Proteins/genetics
  • Homeodomain Proteins/metabolism*
  • Phosphorylation
  • Positive Transcriptional Elongation Factor B/genetics
  • Positive Transcriptional Elongation Factor B/metabolism
  • Promoter Regions, Genetic*
  • RNA Polymerase II/genetics
  • RNA Polymerase II/metabolism
  • Transcriptional Activation*
  • Zebrafish
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed
24480644 Full text @ Dev. Cell
Abstract

Hox proteins form complexes with TALE cofactors from the Pbx and Prep/Meis families to control transcription, but it remains unclear how Hox:TALE complexes function. Examining a Hoxb1b:TALE complex that regulates zebrafish hoxb1a transcription, we find maternally deposited TALE proteins at the hoxb1a promoter already during blastula stages. These TALE factors recruit histone-modifying enzymes to promote an active chromatin profile at the hoxb1a promoter and also recruit RNA polymerase II (RNAPII) and P-TEFb. However, in the presence of TALE factors, RNAPII remains phosphorylated on serine 5 and hoxb1a transcription is inefficient. By gastrula stages, Hoxb1b binds together with TALE factors to the hoxb1a promoter. This triggers P-TEFb-mediated transitioning of RNAPII to the serine 2-phosphorylated form and efficient hoxb1a transcription. We conclude that TALE factors access promoters during early embryogenesis to poise them for activation but that Hox proteins are required to trigger efficient transcription.

Genes / Markers
Figures
Expression
Phenotype
Mutation and Transgenics
Human Disease / Model Data
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping
Errata and Notes