PUBLICATION

Pbx acts with Hand2 in early myocardial differentiation

Authors
Maves, L., Tyler, A., Moens, C.B., and Tapscott, S.J.
ID
ZDB-PUB-090720-3
Date
2009
Source
Developmental Biology   333(2): 409-418 (Journal)
Registered Authors
Maves, Lisa, Moens, Cecilia
Keywords
pbx, hand2, zebrafish, heart development, muscle differentiation
MeSH Terms
  • Animals
  • Base Sequence
  • Basic Helix-Loop-Helix Transcription Factors/metabolism*
  • Cell Differentiation
  • DNA, Complementary/metabolism
  • Gene Expression Regulation, Developmental*
  • Heart/embryology*
  • Heart/physiology
  • Homeodomain Proteins/metabolism
  • Homeodomain Proteins/physiology*
  • Molecular Sequence Data
  • Muscles/metabolism*
  • Oligonucleotide Array Sequence Analysis
  • RNA, Messenger/metabolism
  • Sequence Homology, Nucleic Acid
  • Zebrafish
  • Zebrafish Proteins/metabolism*
  • Zebrafish Proteins/physiology*
PubMed
19607825 Full text @ Dev. Biol.
Abstract
Transcription factors of the basic helix-loop-helix (bHLH) family are critical regulators of muscle cell differentiation. For example, Myod drives skeletal muscle differentiation, and Hand2 potentiates cardiac muscle differentiation. Understanding how these bHLH factors regulate distinct transcriptional targets in a temporally and spatially controlled manner is critical for understanding their activity in cellular differentiation. We previously showed that Pbx homeodomain proteins modulate the activity of Myod to promote the differentiation of fast-twitch skeletal muscle. Here, we test the hypothesis that Pbx proteins are also necessary for cardiac muscle differentiation through interacting with Hand2. We show that Pbx proteins are required for the activation of cardiac muscle differentiation in zebrafish embryos. Loss of Pbx activity leads to delay of myocardial differentiation and subsequent defective cardiac morphogenesis, similar to reduced Hand2 activity. Genetic interaction experiments support the hypothesis that Pbx proteins modulate the activity of Hand2 in myocardial differentiation. Furthermore, we show that Pbx proteins directly bind the promoter of the myocardial differentiation gene myl7 in vitro, supporting a direct role for Pbx proteins in promoting cardiac muscle differentiation. Our findings demonstrate new roles for Pbx proteins in vertebrate cardiac development and also provide new insight into connections between the transcriptional regulation of skeletal and cardiac muscle differentiation programs.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping