Iroquois homeodomain transcription factors in heart development and function

Circ Res. 2012 May 25;110(11):1513-24. doi: 10.1161/CIRCRESAHA.112.265041.


Numerous cardiac transcription factors play overlapping roles in both the specification and proliferation of the cardiac tissues and chambers during heart development. It has become increasingly apparent that cardiac transcription factors also play critical roles in the regulation of expression of many functional genes in the prenatal and postnatal hearts. Accordingly, mutations of cardiac transcription factors cannot only result in congenital heart defects but also alter heart function thereby predisposing to heart disease and cardiac arrhythmias. In this review, we summarize the roles of Iroquois homeobox (Irx) family of transcription factors in heart development and function. In all, 6 Irx genes are expressed with distinct and overlapping patterns in the mammalian heart. Studies in several animal models demonstrate that Irx genes are important for the establishment of ventricular chamber properties, the ventricular conduction system, as well as heterogeneity of the ventricular repolarization. The molecular mechanisms by which Irx proteins regulate gene expression and the clinical relevance of Irx functions in the heart are discussed.

Publication types

  • Research Support, American Recovery and Reinvestment Act
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Gene Expression Regulation, Developmental
  • Heart / embryology
  • Heart / growth & development*
  • Heart / physiopathology
  • Heart Conduction System / growth & development
  • Heart Conduction System / metabolism
  • Heart Diseases / genetics
  • Heart Diseases / metabolism
  • Heart Diseases / physiopathology
  • Heart Ventricles / growth & development
  • Heart Ventricles / metabolism
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism*
  • Humans
  • Myocytes, Cardiac / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*


  • Homeodomain Proteins
  • Transcription Factors