Document Detail

Haploinsufficiency of the cardiac transcription factor Nkx2-5 variably affects the expression of putative target genes.
MedLine Citation:
PMID:  15972800     Owner:  NLM     Status:  MEDLINE    
Heterozygous mutations of the cardiac transcription factor Nkx2-5 cause congenital heart disease. To elucidate the molecular pathways of transcription factor mutant phenotypes or diseases, direct targets are commonly sought in studies of homozygous null mutant animals and by heterologous promoter-reporter gene transactivation assays. The expression of putative target genes in a physiologic range of transcription factor concentration, however, is often not examined. Heterozygous Nkx2-5 knockout (Nkx2-5+/-) mice have no more than half-normal levels of Nkx2-5 protein. We therefore measured the mRNA expression of four putative targets of the cardiac transcription factor Nkx2-5 in wild-type and Nkx2-5+/- animals in a variety of developmental and pathologic states. Wild-type and Nkx2-5+/- embryonic hearts expressed similar levels of atrial natriuretic factor (ANF), brain natriuretic peptide (BNP), the RNA helicase Csm, and homeodomain only protein HOP. In the failing adult ventricle, ANF and BNP were up-regulated to the same extent in wild-type and Nkx2-5+/- myocardium. Csm and HOP were down-regulated in heart failure, and Nkx2-5+/- hearts expressed about half-normal levels in healthy and failing states. No consistent relationship existed between the expression of putative transcriptional targets and Nkx2-5 gene dosage in the physiologically relevant range. Any dependence of gene expression on Nkx2-5 gene dosage is affected by factors specific to the individual gene and the physiologic context.
Patrick Y Jay; Olga Rozhitskaya; Oleg Tarnavski; Megan C Sherwood; Adam L Dorfman; Yali Lu; Tomomi Ueyama; Seigo Izumo
Publication Detail:
Type:  Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S.     Date:  2005-06-22
Journal Detail:
Title:  FASEB journal : official publication of the Federation of American Societies for Experimental Biology     Volume:  19     ISSN:  1530-6860     ISO Abbreviation:  FASEB J.     Publication Date:  2005 Sep 
Date Detail:
Created Date:  2005-08-29     Completed Date:  2006-03-06     Revised Date:  2012-02-15    
Medline Journal Info:
Nlm Unique ID:  8804484     Medline TA:  FASEB J     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1495-7     Citation Subset:  IM    
Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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MeSH Terms
Atrial Natriuretic Factor / genetics
Connexins / genetics
Fetal Heart / metabolism
Gene Expression Regulation*
Homeodomain Proteins / genetics,  physiology*
Myocardium / chemistry,  metabolism*
Natriuretic Peptide, Brain / genetics
Transcription Factors / genetics,  physiology*
Grant Support
Reg. No./Substance:
0/Connexins; 0/Homeodomain Proteins; 0/Hop protein, mouse; 0/Nkx2-5 protein, mouse; 0/Transcription Factors; 0/connexin 40; 114471-18-0/Natriuretic Peptide, Brain; 85637-73-6/Atrial Natriuretic Factor

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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