Zebrafish serotonin-N-acetyltransferase-2 gene regulation:: Pineal-restrictive downstream module contains a functional E-box and three photoreceptor conserved elements
Zebrafish serotonin-N-acetyltransferase-2 gene regulation:: Pineal-restrictive downstream module contains a functional E-box and three photoreceptor conserved elements
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DOI：
10.1210/me.2003-0439
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发表时间：
2004-05-01
影响因子：
--
通讯作者：
Gothilf, Y
中科院分区：
文献类型：
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作者：
Appelbaum, L;Toyama, R;Gothilf, Y
松果体功能由一组非常窄表达的基因定义，这些基因编码光周期转导和节律性褪黑激素分泌所需的蛋白质。这些蛋白质之一是血清素N-乙酰转移酶（芳基烷基胺N-乙酰转移酶，AANAT），它控制褪黑激素产生的每日节律。在这里，松果体特异性表达的斑马鱼aanat-2（zfaanat-2）进行了研究，在体内瞬时表达分析的启动子-报告构建体，这表明，特异性是由两个区域位于12 kb远离对方。一个是5 '-侧翼区，另一个是257-bp的序列，位于转录区下游6 kb。该3 '端序列被命名为松果体限制性下游模块（PRDM），具有双重功能：增强松果体表达和抑制松果体外表达。前者是PRDM的自主性质，而后者的功能需要与zfaanat-2的上游调控区相互作用。PRDM序列的功能分析表明，三个感光细胞保守元件（TAATC）和一个单一的完美的E-box（CACGTG）是至关重要的PRDM的双重功能。这些结果表明zfaanat-2的松果体特异性是由PRDM的双重功能以及上游调控区与下游感光细胞保守元件和E-box元件之间的相互作用决定的。
Pineal function is defined by a set of very narrowly expressed genes that encode proteins required for photoperiodic transduction and rhythmic melatonin secretion. One of these proteins is serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase, AANAT), which controls the daily rhythm in melatonin production. Here, pineal-specific expression of the zebrafish aanat-2 (zfaanat-2) was studied using in vivo transient expression analyses of promoter-reporter constructs; this revealed that specificity is determined by two regions located 12 kb away from each other. One is the 5'-flanking region, and the other is a 257-bp sequence, located 6 kb downstream of the transcribed region. This 3'-sequence, designated pineal-restrictive downstream module (PRDM), has a dual function: enhancement of pineal expression and inhibition of extrapineal expression. The former is an autonomic property of PRDM whereas the later function requires interaction with the upstream regulatory region of zfaanat-2. Functional analyses of the PRDM sequence revealed that three photoreceptor conserved elements (TAATC) and a single perfect E-box (CACGTG) are crucial for the dual function of PRDM. These results indicate that pineal specificity of zfaanat-2 is determined by the dual functionality of the PRDM and the interaction between upstream regulatory region and downstream photoreceptor conserved elements and E-box element.