Isolation and characterization of Schistosoma mansoni constitutive androstane receptor
Isolation and characterization of Schistosoma mansoni constitutive androstane receptor
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DOI：
10.1016/j.molbiopara.2006.02.017
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发表时间：
2006-07-01
影响因子：
1.5
通讯作者：
LoVerde, Philip T.
中科院分区：
文献类型：
--
作者：
Hu, Rong;Wu, Wenjue;LoVerde, Philip T.
通过筛选曼氏血吸虫成虫 cDNA 文库，分离出编码脊椎动物 CAR/PXR/NDR 组核受体的曼氏血吸虫同源物的全长 cDNA 克隆，称为 SmCAR。 SmCAR 是一种 702 个氨基酸的蛋白质，保留了核受体超家族成员的典型结构域组织。同源性搜索表明，SmCAR 与小鼠组成型雄甾烷受体 (CAR) 具有最高的同源性。与其来自无脊椎动物的直系同源物一样，SmCAR 在 DNA 结合域中包含 ESCKA 的 P 盒序列。 P 盒对于确定 DNA 与核受体的结合特异性非常重要。 SmCAR mRNA 在曼氏链霉菌生命周期的每个阶段都有表达，其中在卵和尾蚴阶段表达水平升高。通过蛋白质印迹分析在血吸虫提取物中检测到两种形式（78 和 81 kDa）的 SmCAR 蛋白。免疫定位研究表明，SmCAR蛋白广泛分布于成虫中，在雄性和雌性蠕虫的皮下以及雌性蠕虫的卵巢、卵黄和卵中都有发现。体外 DNA 结合测定表明，SmCAR 与 hsp27 蜕皮激素反应元件 (EcRE) 以及血吸虫 p14 基因上游区域结合。 AGTGCA 半位点对于 SmCAR 与 p14 基因上游区域的结合至关重要。因此，AGTGCA 可能充当含有核受体的 ESCKA 的高亲和力结合半位点。 (c) 2006 Elsevier B.V. 保留所有权利。
Full length cDNA clones encoding a Schistosoma mansoni homologue of vertebrate CAR/PXR/NDR group nuclear receptor, termed SmCAR were isolated from screening a S. mansoni adult worm cDNA library. SmCAR is a 702 amino acid protein which retains a typical domain organization of nuclear receptor superfamily members. A homology search demonstrated that SmCAR exhibits the highest homology with mouse constitutive androstane receptor (CAR). Like its orthologues from invertebrates, SmCAR contains a P box sequence of ESCKA in the DNA binding domain. The P box is important in determining the DNA binding specificity for nuclear receptors. SmCAR mRNA is expressed in every stage of S. mansoni life cycle with an elevated expression level in egg and cercaria stages. Two forms (78 and 81 kDa) of SmCAR protein were detected in schistosome worm extract by Western blot analysis. SmCAR protein was demonstrated to be widely distributed in adult worms by immunolocalization studies, being found in the subtegument in both male and female worms and in the ovaries, vitellaria and eggs in female worms. In vitro DNA binding assays demonstrated that SmCAR binds to the hsp27 ecdysone response element (EcRE) as well as schistosome p14 gene upstream region. The AGTGCA half site is essential for binding of SmCAR to the p14 gene upstream region. Therefore, AGTGCA probably serves as a high affinity binding half site for ESCKA containing nuclear receptors. (c) 2006 Elsevier B.V. All rights reserved.