Jumonji represses atrial natriuretic factor gene expression by inhibiting transcriptional activities of cardiac transcription factors
Jumonji represses atrial natriuretic factor gene expression by inhibiting transcriptional activities of cardiac transcription factors
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DOI：
10.1128/mcb.24.23.10151-10160.2004
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发表时间：
2004-12-01
影响因子：
5.3
通讯作者：
Lee, Y
中科院分区：
文献类型：
--
作者：
Kim, T;Chen, JQ;Lee, Y
纯合敲除jumonji（jmj）基因的小鼠表现出心脏发育异常和心脏特异性基因（包括心房利钠因子（ANF））调节缺陷。心钠素是心脏分化的最早标志物之一，也是心脏肥大的标志。在这里，我们表明，JMJ抑制ANF基因的表达抑制Nkx2.5和GATA 4的转录活性。JMJ抑制含有ANF启动子-增强子或含有Nkx2.5或GATA 4结合共有序列的报告基因的Nkx2.5或GATA 4依赖性激活。JMJ在体外和体内与Nkx2.5和GATA 4物理结合，如通过谷胱甘肽S-转移酶下拉和免疫沉淀测定所确定的。使用突变分析，我们绘制了JMJ，Nkx2.5和GATA 4中的蛋白质-蛋白质相互作用结构域。我们确定了两个DNA结合位点的JMJ在ANF增强子的凝胶迁移率变动分析。然而，这些JMJ结合位点似乎不介导ANF抑制JMJ。JMJ的突变分析表明JMJ的蛋白-蛋白相互作用结构域介导了ANF基因表达的抑制。因此，JMJ可能在下调心钠素基因表达和心脏发育中起重要作用。
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.