禾谷镰刀菌基因组中含寄主靶向模体分泌蛋白功能的初步分析

基于生物信息学的方法,以SignalP v3.0、TargetP v1.01、Big-PI Predictor和TMHMM v2.0四个分析软件对禾谷镰刀菌(Fusarium graminearum Schw.)全基因组的11 640个蛋白编码基因的N-端氨基酸序列进行信号肽分析,预测出606个潜在的分泌蛋白编码基因.通过对这些潜在的分泌蛋白进行MEME软件分析,发现其中有157个分泌蛋白的剪切点下游120氨基酸残基范围内具有一个保守的RXLX模体,其中有79个分泌蛋白具有可预测的功能性描述,包括FG00023.1具有与草酸盐氧化酶1有关的功能,FG01588.1具有与1,4-α-葡糖苷酶葡聚糖有关的功能,这些基因可作为禾谷镰刀菌致病相关的候选基因.其中FG04097.1编码的具有与丝氨酸型蛋白酶有关的功能在致病疫霉和疟原虫真核寄生物中具有相似保守的寄主靶标模体的效应蛋白中也观察到,但FG09127.1,FG05287.1编码的蛋白尚未被证明参与致病过程的研究报道.深入研究分泌蛋白将有助于明确植物与病原微生物互作的分子机制.利用禾谷镰刀菌基因组学研究成果,结合计算机技术和生物信息学的方法,分析其分泌蛋白组学,将有助于全面掌握其致病因子的结构与功能.对于这些蛋白功能的比较研究,将有利于对禾谷镰刀菌致病性的分子机制的探索,并为设计新的防治措施提供理论依据.

Primary Analysis of Host-Targeting-motif Harbored Secreted Proteins in Genome of Fusarium graminearum

The Internet-based software such as the SignalP v3.0,TargetP v1.01 ,big-PI predictor and TMHMM v2.0 were combined to predict the N-terminal-signal-peptide-dependent secretory proteins among the 11640 ORFs in genome of plant pathogenic fungus,Fusarium graminearum. The results showed that 606 ORFs were the potential secretory proteins according to our set of four prediction algorithms. To analysis the potential proteins involved in virulence of the fungus,MEME was used to screen all ORFs of secretory proteins. Among these,157 RXLX motif-containing proteins were found from 100 residues after N-terminal signal peptide cleavage site and 79 proteins have an assigned function by homology based on PEDANT database. Among these, FG01588.1 and FG04097.1 ,encoding glucanl, 4-alpha-glucosidase and PRCl-carboxypeptidase y,serine-type protease,respectively,was found in RXLX-motif containing protein in Phytophthora and Plasmodium as well. Many of the these proteins are protease or lipase,probably associate with pathogeniciw,but the evidence of these proteins and pathogeniciW or virulence the fungus remain to be clarified.