中型无绿藻不同致病性菌株的差异表达蛋白筛选及相关蛋白功能研究

Proteomic analysis of human pathogenic Prototheca zopfii strains and related protein functions

目的研究不同致病性中型无绿藻菌株的蛋白组学差异,并对差异蛋白进行功能研究,从而探索无绿藻的致病机制。方法应用液相色谱串联质谱法(LC-MS/MS),通过同位素标记相对和绝对定量技术(iTRAQ),测定中型无绿藻环境株(基因1型)与中型无绿藻临床分离株(基因2型)之间的差异表达蛋白,并应用生物信息学技术对鉴定得到的差异表达蛋白进行功能分析。结果共鉴定得到245个不同表达蛋白,其中表达差异>1.5倍的蛋白共有35个,包括16个上调蛋白和19个下调蛋白;生物信息学分析发现,在致病的基因2型中型无绿藻菌株中,差异表达蛋白的功能主要涉及抑制能量产生与转化,降低碳水化合物的转运和代谢以及加强翻译等生物学过程。结论无绿藻的致病涉及多种蛋白表达的改变,iTRAQ技术可以有效筛选出基因1型与基因2型中型无绿藻的差异表达蛋白,对进一步探索无绿藻病的发病机制,干预或治疗无绿藻病具有重要意义,并为研究无绿藻感染治疗靶点提供了理论基础。

OBJECTIVE To investigate the difference in proteomics among the different genotypes of pathogenic Prototheca sppand study the functions of the differential proteins so as to explore the pathogenic mechanisms of the Prototheca spp.METHODS By means of liquid chromatography tandem mass spectrometry（LC-MS/MS）,the differentially expressed proteins of the environmental P.zopfii strain（the genotype 1）and clinical P.zopfii strain（genotype 2）were quantified by isobaric tag for relative and absolute quantitation（iTRAQ）-based quantitative proteomics.RESULTS A total of 245 proteins were identified,of which 35 displayed a differential expression more than 1.5folds,including 16up-regulated proteins and 19down-regulated proteins.The biological information analysis indicated that the functions of the differentially expressed proteins in the P.zopfii strains with genotype 2mainly involved the biological processes such as inhibition of energy production and conversion,reduction of transport and metabolism of carbohydrates,and enhancement of translation.CONCLUSIONThe pathogenic mechanisms of the P.zopfii involve the change of expression of multiple proteins,the iTRAQ technique can effectively screen out the differentially expressed proteins in the genotype 1and genotype 2 P.zopfii strains,which have great significance to further investigation of pathogenic mechanisms,interventions,and treatment of P.zopfii disease and provide theoretical basis for targeted treatment of the P.zopfii infection.