Characterization of the region of the aryl hydrocarbon receptor required for ligand dependency of transactivation using chimeric receptor between Drosophila and Mus musculus
Characterization of the region of the aryl hydrocarbon receptor required for ligand dependency of transactivation using chimeric receptor between Drosophila and Mus musculus
复制标题
DOI：
10.1016/j.bbagrm.2009.06.003
复制
发表时间：
2009-06-01
影响因子：
4.7
通讯作者：
Kikuchi, Hideaki
中科院分区：
文献类型：
--
作者：
Kudo, Kyoko;Takeuchi, Takeshi;Kikuchi, Hideaki
芳香烃受体(AhR)是一种配体激活的转录因子。尽管2，3，7，8-四氯二苯并对二恶英(TCDD)对许多脊椎动物有很高的亲和力和毒性，但包括无刺果蝇在内的无脊椎动物AHR不能结合外源化学物质作为配体。为了分析AhR的配体结合域(LBD)，我们使用了小鼠和果蝇AhR之间的嵌合体。嵌合AhR揭示了LBD决定了果蝇AhR的结构性反式激活或小鼠AhR的配体依赖的激活。LBD被进一步分为对应于小鼠序列的230-300、301-361和361-420个氨基酸的三个块。6个嵌合蛋白阐明了果蝇LBD的291-350氨基酸，即中间区域，在没有配体结合的情况下需要保持蛋白质的活性形式，而在小鼠AhR中，需要这个区域在没有配体的情况下保持蛋白质的非活性形式。此外，位于小鼠LBD中间区域的Arg346被鉴定为对通过定点突变激活AhR至关重要的氨基酸。(C)2009爱思唯尔B.V.保留所有权利。
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcriptional factor. Although 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is high affinity and toxic to many vertebrate animals, invertebrate AhRs including Drosophila melanogaster AhR (spineless) have no ability to bind exogenous chemicals as ligands. To analyze the ligand-binding domain (LBD) of AhR, we used chimeras between mouse and Drosophila AhR. The chimeric AhR revealed that the LBD determines constitutive transactivation in Drosophila AhR or ligand-dependent activation in mouse AhR. The LBD was further divided into three blocks that corresponded to amino acids 230-300, 301-361, and 361-420 of the mouse sequence. Six chimeric proteins clarified that amino acids 291-350 of the Drosophila LBD, i.e. the middle region, were required to keep the protein in the active form in the absence of ligand binding, whereas in the mouse AhR, this region was required to maintain the protein in the inactive form in the absence of ligand. Furthermore, Arg346 in the middle region of the mouse LBD, was identified as amino acids that were critical for AhR activation by site-directed mutagenesis. (C) 2009 Elsevier B.V. All rights reserved.