虾肝肠胞虫全基因组分泌蛋白的预测分析

Genome-Wide Prediction and Analysis of Secreted Proteins of Enterocytozoon hepatopenaei

关键词:  虾肝肠胞虫  基因组  分泌蛋白  信号肽  基序

Key words:  Enterocytozoon hepatopenaei  Genome  Secreted protein  Signal peptide  Motif

摘要:

分泌蛋白是在细胞内合成后分泌到细胞外起作用的蛋白质，其在许多原生动物寄生虫操纵宿主细胞和影响虫体的毒力中起着重要作用。虾肝肠胞虫(Enterocytozoon hepatopenaei，EHP)是一种可感染多种经济虾类的专性细胞内寄生虫，是近年来影响全球对虾养殖生产较严重的病害之一。本研究利用真核生物分泌蛋白预测流程EuSecPred2.0对EHP全基因组的分泌蛋白进行预测，并对分泌蛋白长度、信号肽长度、切割位点处氨基酸分布等信息进行分析，对分泌蛋白功能进行分析。结果显示，分泌蛋白氨基酸长度主要集中在30~400 aa之间；信号肽长度集中在9~32 aa之间；信号肽切割位点处以疏水性氨基酸为主。对信号肽进行基序分析，发现存在基序NV[VT][IK]CA[ED][SA]。对所获蛋白质进行功能注释，发现了多种与微孢子虫黏附侵染、调节细胞周期和免疫反应等相关的关键蛋白。研究结果有助于了解EHP对宿主的侵染机制，同时为进一步明确EHP的致病相关因子提供理论依据。

Abstract:

Secreted proteins are synthesized in cells and secreted to function outside the cell. They play an important role in the manipulation of host cells and the virulence of many eukaryotic protozoan parasites. Enterocytozoon hepatopenaei (EHP) is an obligate intracellular parasite that can infect a variety of economically valuable shrimp species, and is one of the most serious diseases affecting global shrimp production. Here, we predict the secreted proteins of the EHP genome with the EuSecPred2.0 pipeline and analyzed the length of these secreted proteins, the length of the signal peptide, and the amino acid distribution at the cleavage site, and annotated the function of secreted proteins. The results show that the length of the secreted proteins ranged from 30 to 400 amino acid residues, the signal peptides covered approximately 9~32 amino acids, and the cleavage sites of the signal peptides were mainly composed of hydrophobic amino acids. Motif analysis revealed a NV[VT][IK]CA[ED][SA] motif in signal peptides. Functional annotation of proteins revealed that a variety of key proteins are involved in adhesion and infection of microsporidia, regulation of cell cycle, and immune response. The results shed light on the infection mechanism of EHP and provide a theoretical basis for further defining the pathogenic factors of EHP.