Wang Jing, Tang Di, Li Wensheng, Xu Jianhai, Liu Qun, Liu Jing
Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing 100193, China.
Exp Parasitol. 2017 Apr;175:21-27. doi: 10.1016/j.exppara.2017.01.004. Epub 2017 Jan 25.
Microneme proteins play an important role in the invasion process of Apicomplexan parasites through adhesion to host cells. We discovered a new N. caninum protein, NcMIC8, which is highly identical to TgMIC8. The NcMIC8 sequence has 2049 bp and no intron in the open reading fragment. It has a molecular weight of 73.8 kDa and contains a signal peptide, a transmembrane region, a low complexity region and 10 epidermal growth factor (EGF) domains. Immuno-fluorescence assay showed that NcMIC8 is located in the microneme. NcMIC8 was secreted to culture medium under stimulation of 1% ethanol, and cleaved to form the mature body of 40 kDa before transporting to microneme or during secretion. Blocking NcMIC8 using anti-NcMIC8 serum effectively inhibited host cell invasion by tachyzoites in vitro. NcMIC8 in the form of mature body interacts with NcMIC3, and the two microneme proteins form a complex probably during transportation. NcMIC8 is a new microneme protein of N. caninum and could be an attractive target for the control of neosporosis.
微线体蛋白在顶复门寄生虫通过黏附宿主细胞的入侵过程中发挥重要作用。我们发现了一种新的犬新孢子虫蛋白NcMIC8，它与TgMIC8高度同源。NcMIC8序列有2049 bp，开放阅读框中无内含子。其分子量为73.8 kDa，包含一个信号肽、一个跨膜区、一个低复杂性区域和10个表皮生长因子（EGF）结构域。免疫荧光分析表明NcMIC8定位于微线体。NcMIC8在1%乙醇刺激下分泌到培养基中，并在转运到微线体之前或分泌过程中被切割形成40 kDa的成熟体。用抗NcMIC8血清阻断NcMIC8可有效抑制速殖子在体外对宿主细胞的入侵。成熟体形式的NcMIC8与NcMIC3相互作用，这两种微线体蛋白可能在转运过程中形成复合物。NcMIC8是犬新孢子虫一种新的微线体蛋白，可能是控制新孢子虫病的一个有吸引力的靶点。
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