EnP1 and EnP2, two proteins associated with the Encephalitozoon cuniculi endospore, the chitin-rich inner layer of the microsporidian spore wall
EnP1 and EnP2, two proteins associated with the Encephalitozoon cuniculi endospore, the chitin-rich inner layer of the microsporidian spore wall
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DOI：
10.1016/j.ijpara.2005.10.005
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发表时间：
2006-03-01
影响因子：
4
通讯作者：
Delbac, F
中科院分区：
文献类型：
--
作者：
Peuvel-Fanget, I;Polonais, V;Delbac, F
微孢子虫是专性细胞内寄生虫，形成具有刚性细胞壁的耐环境孢子。该壁包括外层或外孢子和富含几丁质的内层或内生孢子。到目前为止，只有一种几丁质脱乙酰酶样蛋白被证明定位于兔脑孢子虫的内生孢子上，而在两种脑孢子虫的外孢子上已经明确地定位了一种或两种蛋白：兔脑原虫的SWP 1和SWP 2。在这里，我们报告了E. EnP 1和EnP 2基因均位于染色体I（分别为ECU 01_0820和ECU 01_1270）上，并且没有已知的同源物。通过免疫筛选E.在兔cDNA文库中，enpl的特征在于小尺寸的5'和3'非翻译区，并且在整个细胞内循环中高度表达。编码的基本40 kDa抗原显示高比例的半胱氨酸残基，主张二硫键在孢子壁组装中的重要作用。EnP 2是一种22 kDa的富含丝氨酸的蛋白质，预计是O-糖基化和糖基化磷脂酰肌醇锚定的。虽然已被确定的二硫苏糖醇可溶性馏分的质谱，这种蛋白质只含有两个半胱氨酸残基。针对大肠杆菌中产生的EnP 1和EnP 2重组蛋白，提出了小鼠多克隆抗体。我们的免疫定位数据表明，EnP 1和EnP 2早在孢子形成开始时就被靶向细胞表面，并最终与成熟孢子壁中富含几丁质的层相关。(c)2005年澳大利亚寄生虫学学会有限公司由爱思唯尔有限公司出版。保留所有权利。
Microsporidia are obligate intracellular parasites forming environmentally resistant spores that harbour a rigid cell wall. This wall comprises an outer layer or exospore and a chitin-rich inner layer or endospore. So far, only a chitin deacetylase-like protein has been shown to localize to the Encephalitozoon cuniculi endospore and either one or two proteins have been clearly assigned to the exospore in two Encephalitozoon species: SWP1 in E. cuniculi, SWP1 and SWP2 in Encephalitozoon intestinalis. Here, we report the identification of two new spore wall proteins in E. cuniculi, EnP1 and EnP2, the genes of which are both located on chromosome I (ECU01_0820 and ECU01_1270, respectively) and have no known homologue. Detected by immunoscreening of an E. cuniculi cDNA library, enpl is characterized by small-sized 5' and 3' untranslated regions and is highly expressed throughout the whole intracellular cycle. The encoded basic 40 kDa antigen displays a high proportion of cysteine residues, arguing for a significant role of disulfide bridges in spore wall assembly. EnP2 is a 22 kDa serine-rich protein that is predicted to be O-glycosylated and glycosylated phosphatidyl inositol-anchored. Although having been identified by mass spectrometry of a dithiothreitol-soluble fraction, this protein contains only two cysteine residues. Mouse polyclonal antibodies were raised against EnP1 and EnP2 recombinant proteins produced in Escherichia coli Our immunolocalisation data indicate that EnP1 and EnP2 are targeted to the cell surface as early as the onset of sporogony and are finally associated with the chitin-rich layer of the wall in mature spores. (c) 2005 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.