Interaction and Assembly of Two Novel Proteins in the Spore Wall of the Microsporidian Species Nosema bombycis and Their Roles in Adherence to and Infection of Host Cells
Interaction and Assembly of Two Novel Proteins in the Spore Wall of the Microsporidian Species Nosema bombycis and Their Roles in Adherence to and Infection of Host Cells
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DOI：
10.1128/iai.03155-14
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发表时间：
2015-01
影响因子：
3.1
通讯作者：
Donglin Yang;G. Pan;Xiaoqun Dang;Yawei Shi;Chunfeng Li;Pai Peng;Bo Luo;Maofei Bian;Yue Song-Yue
中科院分区：
文献类型：
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作者：
Donglin Yang;G. Pan;Xiaoqun Dang;Yawei Shi;Chunfeng Li;Pai Peng;Bo Luo;Maofei Bian;Yue Song-Yue
摘要 微孢子虫是专性细胞内寄生虫，具有坚硬的孢子壁，可以抵御各种环境压力。尽管对孢子壁进行了广泛的描述，但对其沉积机制或其在细胞粘附和感染中所起的作用知之甚少。在这项研究中，我们报告了微孢子虫种家蚕微孢子虫中两种新型孢子壁蛋白 SWP7 和 SWP9 的鉴定和表征。 SWP7和SWP9主要分别定位于成熟孢子的外孢子和内孢子以及孢子的细胞质。此外，SWP9的一部分比SWP7更早地靶向孢子母细胞的孢子壁。 SWP7 和 SWP9 都特异性地共定位于成熟孢子的孢子壁。此外，免疫沉淀、远蛋白印迹、未还原 SDS-PAGE 和酵母双杂交数据证明 SWP7 与 SWP9 相互作用。几丁质结合测定表明，在总孢子蛋白中，SWP9和SWP7可以与家蚕去蛋白的几丁质孢子衣（DCSC）结合。然而，重组蛋白rSWP7-His与DCSC的结合依赖于rSWP9-谷胱甘肽S-转移酶(GST)与DCSC的结合。最后，rSWP9-GST、抗SWP9和抗SWP7抗体降低了孢子粘附和宿主细胞的感染。总之，SWP7和SWP9可能具有重要的结构能力，并在体外调节宿主细胞粘附和感染中发挥重要作用。 SWP9 的一个可能的主要功能是作为支架蛋白，支持形成家蚕孢子壁的其他蛋白（例如 SWP7）。
ABSTRACT Microsporidia are obligate intracellular parasites with rigid spore walls that protect against various environmental pressures. Despite an extensive description of the spore wall, little is known regarding the mechanism by which it is deposited or the role it plays in cell adhesion and infection. In this study, we report the identification and characterization of two novel spore wall proteins, SWP7 and SWP9, in the microsporidian species Nosema bombycis. SWP7 and SWP9 are mainly localized to the exospore and endospore of mature spores and the cytoplasm of sporonts, respectively. In addition, a portion of SWP9 is targeted to the spore wall of sporoblasts earlier than SWP7 is. Both SWP7 and SWP9 are specifically colocalized to the spore wall in mature spores. Furthermore, immunoprecipitation, far-Western blotting, unreduced SDS-PAGE, and yeast two-hybrid data demonstrated that SWP7 interacted with SWP9. The chitin binding assay showed that, within the total spore protein, SWP9 and SWP7 can bind to the deproteinated chitin spore coats (DCSCs) of N. bombycis. However, binding of the recombinant protein rSWP7-His to the DCSCs is dependent on the combination of rSWP9–glutathione S-transferase (GST) with the DCSCs. Finally, rSWP9-GST, anti-SWP9, and anti-SWP7 antibodies decreased spore adhesion and infection of the host cell. In conclusion, SWP7 and SWP9 may have important structural capacities and play significant roles in modulating host cell adherence and infection in vitro. A possible major function of SWP9 is as a scaffolding protein that supports other proteins (such as SWP7) that form the integrated spore wall of N. bombycis.