Epididymis-specific lipocalin promoters.
Epididymis-specific lipocalin promoters.
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DOI：
10.1111/j.1745-7262.2007.00300.x
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发表时间：
2007-07
影响因子：
2.9
通讯作者：
Kichiya Suzuki;Xiuping Yu;P. Chaurand;Y. Araki;J. Lareyre;R. Caprioli;M. Orgebin‐Crist;R. Matusik
中科院分区：
文献类型：
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作者：
Kichiya Suzuki;Xiuping Yu;P. Chaurand;Y. Araki;J. Lareyre;R. Caprioli;M. Orgebin‐Crist;R. Matusik
我们的目标是破译附睾基因的组织特异性表达所需的DNA序列。已知至少6种附睾特异性脂质运载蛋白基因。这些在附睾中受到不同的调节和区域化。脂质运载蛋白5（Lcn 5或mE-RABP）和脂质运载蛋白8（Lcn 8或mEP 17）是属于附睾特异性脂质运载蛋白基因簇的同源基因。Lcn 5基因的5 kb启动子片段和Lcn 8基因的5.3kb启动子片段都可以指导附睾中的转基因表达（Lcn 5到远端头，Lcn 8到起始片段），表明这些启动子片段含有附睾特异性基因表达的重要顺式调控元件。为了进一步确定调控基因表达的片段，在转基因小鼠和永生化附睾细胞系中检查了Lcn 5启动子。连续缺失后，Lcn 5基因的1.8 kb启动子片段足以在转基因小鼠中进行组织特异性和区域特异性基因表达。瞬时转染分析表明，转录因子叉头框A2（Foxa 2）与雄激素受体相互作用，并结合到1.2 kb和1.3 kb之间的Lcn 5启动子的100 bp片段，Foxa 2的表达抑制雄激素依赖性诱导的Lcn 5启动子活性。免疫组织化学表明，在内源性Lcn 5基因表达被抑制的附睾中Foxa 2的表达受限，并且Lcn 5启动子的Foxa 2抑制与Lcn 5在体部和尾部的表达缺乏一致。我们的方法为进一步分析附睾脂质运载蛋白基因调控和灵活控制附睾功能提供了基本策略。
Our goal is to decipher which DNA sequences are required for tissue-specific expression of epididymal genes. At least 6 epididymis-specific lipocalin genes are known. These are differently regulated and regionalized in the epididymis. Lipocalin 5 (Lcn5 or mE-RABP) and Lipocalin 8 (Lcn8 or mEP17) are homologous genes belonging to the epididymis-specific lipocalin gene cluster. Both the 5 kb promoter fragment of the Lcn5 gene and the 5.3 kb promoter fragment of the Lcn8 gene can direct transgene expression in the epididymis (Lcn5 to the distal caput and Lcn8 to the initial segment), indicating that these promoter fragments contain important cis-regulatory element(s) for epididymis-specific gene expression. To define further the fragments regulating gene expression, the Lcn5 promoter was examined in transgenic mice and immortalized epididymal cell lines. After serial deletion, the 1.8 kb promoter fragment of the Lcn5 gene was sufficient for tissue-specific and region-specific gene expression in transgenic mice. Transient transfection analysis revealed that a transcription factor forkhead box A2 (Foxa2) interacts with androgen receptor and binds to the 100 bp fragment of the Lcn5 promoter between 1.2 kb and 1.3 kb and that Foxa2 expression inhibits androgen-dependent induction of the Lcn5 promoter activity. Immunohistochemistry indicated a restricted expression of Foxa2 in the epididymis where endogenous Lcn5 gene expression is suppressed and that the Foxa2 inhibition of the Lcn5 promoter is consistent with the lack of expression of Lcn5 in the corpus and cauda. Our approach provides a basic strategy for further analysis of the epididymal lipocalin gene regulation and flexible control of epididymal function.