Characterization of a novel otubain-like protease with deubiquitination activity from Nosema bombycis (Microsporidia)
Characterization of a novel otubain-like protease with deubiquitination activity from Nosema bombycis (Microsporidia)
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DOI：
10.1007/s00436-015-4624-7
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发表时间：
2015-07
影响因子：
2
通讯作者：
Ying Wang;Xiaoqun Dang;Bo Luo;Chunfeng Li;Mengxian Long;Tian Li;Zhi Li;G. Pan;Zeyang Zhou
中科院分区：
文献类型：
--
作者：
Ying Wang;Xiaoqun Dang;Bo Luo;Chunfeng Li;Mengxian Long;Tian Li;Zhi Li;G. Pan;Zeyang Zhou
耳管蛋白是最近发现的去泛素化酶（DUB）家族。它们参与多种生物过程，包括蛋白质降解、信号转导和细胞免疫应答。在过去的十年中，一些微孢子虫的基因组已经发表，但是，很少有人知道在这些广泛传播的专性细胞内寄生虫的otubain蛋白酶。在这里，我们的特点是一个25 kDa的otubain样蛋白酶（NbOTU 1）从微孢子虫微孢子虫家蚕，病原体引起微粒子病的经济上重要的昆虫家蚕。序列分析表明，该蛋白含有一个保守的催化三联体的otubains组成的天冬氨酸，半胱氨酸和组氨酸残基。RT-PCR检测结果显示，感染后第3天，Nbotu 1基因开始表达。免疫荧光分析表明NbOTU 1定位于N.蚕免疫电镜观察发现NbOTU 1主要定位于孢子内壁和质膜附近。体外去泛素化分析证实重组NbOTU 1具有去泛素化活性。总之，一种新的微孢子虫otubain样蛋白酶NbOTU 1在N. bombycis，证明其亚细胞定位和去泛素化活性。本研究为进一步研究微管蛋白在微孢子虫中的功能提供了基础参考。
Otubains are a recently identified family of deubiquitinating enzymes (DUBs). They are involved in diverse biological processes including protein degradation, signal transduction, and cell immune response. Several microsporidian genomes have been published in the last decade; however, little is known about the otubain-like protease in these widely-spread obligate intracellular parasites. Here, we characterized a 25 kDa otubain-like protease (NbOTU1) from the microsporidian Nosema bombycis, the pathogen causing pebrine disease in the economically important insect Bombyx mori. Sequence analysis showed that this protein contained a conserved catalytic triad of otubains composed of aspartate, cysteine, and histidine residues. The expression of Nbotu1 began on day 3 postinfection as determined by the RT-PCR method. Immunofluorescence analysis indicated that NbOTU1 is localized on the spore wall of N. bombycis. The subcellular localization of the NbOTU1 was further detected with immunoelectron microscopy, which showed that NbOTU1 is localized at the regions around endospore wall and plasma membrane. Deubiquitination analysis confirmed that the recombinant NbOTU1 possessed deubiquitination activity in vitro. Taken together, a novel microsporidian otubain-like protease NbOTU1 was partially characterized in N. bombycis, demonstrating its subcellular location and deubiquitination activity. This study provided a basic reference for further dissecting the function of otubains in microsporidia.