Jiangsu University of Science and Technology, Zhenjiang, 212018, Jiangsu Province, China.
College of Life Sciences, Zaozhuang University, Zaozhuang, 277160, Shandong Province, China.
Parasitol Res. 2021 Jun;120(6):2125-2134. doi: 10.1007/s00436-021-07129-4. Epub 2021 Mar 26.
As one of the core framework proteins of nuclear pore complex (NPC), nucleoporin Nupl70 acts as a structural adapter between the nucleolus and nuclear pore membrane and maintains the stability of NPC structure through interaction with other proteins. In this study, we identified a Nup170 protein in the microsporidian Nosema bombycis for the first time and named it as NbNup170. Secondary structure prediction showed that the NbNup170 contains α-helices and random coils. The three-dimensional structure of NbNup170 is elliptical in shape. Phylogenetic analysis based on the Nup170 and homologous sequences showed that N. bombycis clustered together with Vairimorpha ceranae and Vairimorpha apis. The immunofluorescence localization results showed that the NbNup170 was located on the plasma membrane of the dormant spore and transferred to the surface of sporoplasm in a punctate pattern when the dormant spore has finished germination, and that NbNup170 was distributed on the nuclear membrane and both sides of the nuclei of early proliferative phase, and only on the nuclear membrane during sporogonic phase in the N. bombycis. qPCR analysis showed that the relative expression level of NbNup170 maintained at a low level from 30 to 78 h post-infection with N. bombycis, then reached the highest at 102 h, while that of NbNup170 was repressed at a very low level throughout its life cycle by RNA interference. These results suggested that NbNup170 protein is involved in the proliferative phase and active during the sporogonic phase of N. bombycis.
作为核孔复合体 (NPC) 的核心框架蛋白之一，核孔蛋白 Nupl70 作为核仁与核膜之间的结构衔接物，通过与其他蛋白质相互作用维持 NPC 结构的稳定性。本研究首次在微孢子虫 Nosema bombycis 中鉴定到 Nup170 蛋白，并将其命名为 NbNup170。二级结构预测表明，NbNup170 含有α-螺旋和无规卷曲。NbNup170 的三维结构呈椭圆形。基于 Nup170 和同源序列的系统发育分析表明，N. bombycis 与 Vairimorpha ceranae 和 Vairimorpha apis 聚为一簇。免疫荧光定位结果表明，NbNup170 位于休眠孢子的质膜上，当休眠孢子完成萌发时，NbNup170 呈点状转移到孢子质的表面，并且在早期增殖阶段，NbNup170 分布在核膜和细胞核的两侧，而在孢子发生阶段则仅分布在核膜上。qPCR 分析显示，感染 N. bombycis 后 30 至 78 小时，NbNup170 的相对表达水平保持在低水平，然后在 102 小时达到最高水平，而在其整个生命周期中，NbNup170 的表达水平通过 RNA 干扰被抑制在非常低的水平。这些结果表明，NbNup170 蛋白参与了 N. bombycis 的增殖阶段，并在孢子发生阶段活跃。
