Jumonji represses atrial natriuretic factor gene expression by inhibiting transcriptional activities of cardiac transcription factors.
Mice with a homozygous knockout of the jumonji (jmj) gene showed abnormal heart development and defective regulation of cardiac-specific genes, including the atrial natriuretic factor (ANF). ANF is one of the earliest markers of cardiac differentiation and a hallmark for cardiac hypertrophy. Here, we show that JMJ represses ANF gene expression by inhibiting transcriptional activities of Nkx2.5 and GATA4. JMJ represses the Nkx2.5- or GATA4-dependent activation of the reporter genes containing the ANF promoter-enhancer or containing the Nkx2.5 or GATA4-binding consensus sequence. JMJ physically associates with Nkx2.5 and GATA4 in vitro and in vivo as determined by glutathione S-transferase pull-down and immunoprecipitation assays. Using mutational analyses, we mapped the protein-protein interaction domains in JMJ, Nkx2.5, and GATA4. We identified two DNA-binding sites of JMJ in the ANF enhancer by gel mobility shift assays. However, these JMJ-binding sites do not seem to mediate ANF repression by JMJ. Mutational analysis of JMJ indicates that the protein-protein interaction domain of JMJ mediates the repression of ANF gene expression. Therefore, JMJ may play important roles in the down-regulation of ANF gene expression and in heart development.
Kim
Tae-Gyun
TG
Department of Anatomy, University of Wisconsin Medical School, 1300 University Ave., Madison, WI 53706, USA.
Chen
Junqin
J
Sadoshima
Junich
J
Lee
Youngsook
Y
D020816:Amino Acid Motifs; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D001665:Binding Sites; D002454:Cell Differentiation; D002478:Cells, Cultured; D004247:DNA / Q000737:chemistry; D004252:DNA Mutational Analysis; D017931:DNA Primers / Q000737:chemistry; D004742:Enhancer Elements, Genetic; D005347:Fibroblasts / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D005982:Glutathione Transferase / Q000378:metabolism; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins / Q000096:biosynthesis; D006720:Homozygote; D047468:Immunoprecipitation; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation; D009206:Myocardium / Q000378:metabolism*; D032383:Myocytes, Cardiac / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D010957:Plasmids / Q000378:metabolism; D063151:Polycomb Repressive Complex 2; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D014176:Protein Biosynthesis; D017434:Protein Structure, Tertiary; D051381:Rats; D014157:Transcription Factors / Q000096:biosynthesis / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection
D017931:DNA Primers; D000072576:Homeobox Protein Nkx-2.5; D018398:Homeodomain Proteins; C093650:Jarid2 protein, mouse; D009419:Nerve Tissue Proteins; C484469:Nkx2-5 protein, mouse; D014157:Transcription Factors; D009320:Atrial Natriuretic Factor; D004247:DNA; D063151:Polycomb Repressive Complex 2; D005982:Glutathione Transferase