Eimeria tenella microneme protein EtMIC3:: identification, localisation and role in host cell infection
Eimeria tenella microneme protein EtMIC3:: identification, localisation and role in host cell infection
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DOI：
10.1016/j.molbiopara.2004.12.002
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发表时间：
2005-03-01
影响因子：
1.5
通讯作者：
Péry, P
中科院分区：
文献类型：
--
作者：
Labbé, M;de Venevelles, P;Péry, P
通过用两个独立的针对卵囊阶段的单克隆抗体筛选子孢子cDNA文库，克隆了编码柔嫩艾美耳球虫蛋白EtMIC3的基因。EtMIC3的推导序列长988个氨基酸。该蛋白质呈现七个串联重复序列，其中四个高度保守的内部重复序列和三个不同的外部重复序列。每个重复序列的特征在于酪氨酸激酶磷酸化位点WRCY和血小板反应蛋白1（TSP1）I型结构域CXXXCG的联想基序。蛋白质EtMIC3定位于游离寄生虫阶段的顶点。在早期的细胞内寄生虫阶段未检测到，但在成熟的寄生虫中合成。当子孢子在41 ℃的完全培养基中孵育时，蛋白质的分泌被诱导。奇怪的是，允许克隆EtMIC3的两种独立的mAb以不同的方式干扰寄生虫生长。一种能够抑制寄生虫入侵，而另一种抑制发育。蛋白质EtMIC3的表达和定位与参与入侵过程的蛋白质一致，如对micromeme蛋白质所预期的。(C)2004 Elsevier B.V.保留所有权利。
The gene coding for Eimeria tenella protein EtMIC3 was cloned by screening a sporozoite cDNA library with two independent monoclonal antibodies raised against the oocyst stage. The deduced sequence of EtMIC3 is 988 amino acids long. The protein presents seven repeats in tandem, with four highly conserved internal repeats and three more divergent external repeats. Each repeat is characterised by a tyrosine kinase phosphorylation site, WRCY, and a reminiscent motif of the thrombospondin1 (TSP1)-type I domain, CXXXCG. The protein EtMIC3 is localised at the apex of free parasite stages. It is not detected in the early intracellular parasite stage but is synthesised in mature schizonts. Secretion of the protein is induced when sporozoites are incubated in complete medium at 41degreesC. Strangely enough, the two independent mAb that allow cloning of EtMIC3 interfere with parasitic growth in different ways. One is able to inhibit parasite invasion whereas the other inhibits development. Expression and localisation of the protein EtMIC3 are consistent with a protein involved in the invasion process as is expected for a micromeme protein. (C) 2004 Elsevier B.V. All rights reserved.