Iroquois homeodomain transcription factors in heart development and function.
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.
Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada.
Kyoung-Han
KH
Kim
Anna
A
Rosen
Benoit G
BG
Bruneau
Chi-chung
CC
Hui
Peter H
PH
Backx
D000818:Animals; D018507:Gene Expression Regulation, Developmental; D006321:Heart / Q000196:embryology / Q000254:growth & development* / Q000503:physiopathology; D006329:Heart Conduction System / Q000254:growth & development / Q000378:metabolism; D006331:Heart Diseases / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D006352:Heart Ventricles / Q000254:growth & development / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D032383:Myocytes, Cardiac / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D018398:Homeodomain Proteins; D014157:Transcription Factors