上海交通大学学报（医学版）

›› 2012, Vol. 32 ›› Issue (9): 1135-.doi: 10.3969/j.issn.1674-8115.2012.09.004

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钩端螺旋体基因组学及蛋白组学研究进展

郭晓奎, 秦金红, 何 平, 朱泳璋   

  1. 上海交通大学 基础医学院病原生物学教研室, 上海 200025
  • 出版日期:2012-09-28 发布日期:2012-09-29
  • 作者简介:郭晓奎（1964—）, 男, 教授, 博士, 博士生导师, 现任上海交通大学基础医学院病原生物学教研室主任、临床微生物学教研室主任；电子信箱: microbiology@sjtu.edu.cn。
  • 基金资助:

    国家自然科学基金(30770111,81171587,81101204)；国家高技术研究发展计划(“八六三”计划)(2011AA02A100)；上海市科委基金(10JC1408200)

Progress on the genomics and proteomics of Leptospira interrogans

GUO Xiao-kui, QIN Jin-hong, HE Ping, ZHU Yong-zhang   

  1. Department of Microbiology and Parasitology, Basic Medical College, Shanghai Jiaotong University School of Medicine, Shanghai 200025, China
  • Online:2012-09-28 Published:2012-09-29

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摘要：

钩端螺旋体（简称钩体）可以引起严重的人兽共患病，是威胁人类健康的传染病之一。课题组率先开展了对中国主要致病流行株56601的全基因组测序工作，测序结果显示钩体有两条染色体，共编码4 727个基因，后经重新注释为3 718个基因。基于56601株的参考序列，对其减毒株IPAV的测序结果表明，除了有101个基因出现突变之外，IPAV株基因组的大小及基因结构组成与56601株相同。基于基因组序列，课题组设计并合成了钩体的基因组芯片，开展了比较基因组学及转录组学的研究。比较基因组学研究结果显示，钩体的核心基因有2 917个，变异基因有275个，并首次发现钩体基因组中存在2个基因岛。模拟体内外钩体生长的温度条件进行转录组学分析，共发现106个基因差异表达，分属9类不同的功能；对有毒株56601及减毒株IPAV进行转录组学分析，发现了差异上调表达的22 kb的类噬菌体片段。对体外培养的56601株进行蛋白组学分析，鉴定出2 540个蛋白，进一步对这些蛋白进行磷酸化、乙酰化及甲基化的修饰进行分析，发现了32个磷酸化位点、46个乙酰化位点和155个甲基化位点。通过分析发现，钩体蛋白的很多修饰方式类似于真核生物，提示钩体在进化上比较特殊。比较毒力株56601与减毒株IPAV的蛋白组异同，一致表达的蛋白1 627个，差异表达的蛋白402个。基于以上基因组学及蛋白组学研究，课题组进一步开展了对钩体相关功能基因的研究，这些研究均为揭示钩体的致病机制、开发钩体的疫苗及诊断试剂、最终防控钩体病奠定了基础。

关键词: 钩端螺旋体, 基因组, 蛋白组

Abstract:

Leptospirosis is a globally important zoonosis which affects people life and health. Our research group sequenced a representative virulent serovar type strain 56601 of Leptospira interrogans serogroup Icterohaemorrhagiae in 2003. The result revealed that Leptospira contains two chromosomes which encoded 4 727 genes. After that, we rectify and reannotate its genome to encode 3 718 genes. In 2010, the virulence-attenuated Leptospira interrogans serovar Lai strain IPAV was sequenced based on the reference sequence of strain 56601. Aside from their highly similar genomic structure and gene order, a total of 101 mutant genes were detected throughout the genome of IPAV. Using DNA microarray of Leptospira, the comparative genomic and genome-wide transcriptional analysis were conducted.  Among the 11 strains tested, the common backbone of the L.interrogans genome was estimated to contain about 2 917 protein-coding sequences (CDSs), while 275 CDSs were found absent from at least one strain. Moreover, two genomic islands (GIs) were firstly reported in strain 56601. Mimic the temperature that Leptospira encountered during infection of a host from an environmental source, expression of 106 genes differed significantly according to temperatures change. The differentially expressed genes belonged to nine functional categories. Through the differential gene expression between Leptospira interrogans serovar Lai type strain 56601 and its corresponding attenuated strain IPAV, a 22-kb genomic island covering a cluster of 34 genes (i.e., genes LA0186 to LA0219) was included, which was further confirmed to be a defect prophage. Combining computational prediction and high-accuracy tandem mass spectra, 2 540 proteins were detected. Subsequently, multiple posttranslational modifications (PTMs) of L.interrogans serovar Lai strain 56601 were detected, containing in total 32 phosphorylated, 46 acetylated and 155 methylated proteins. The PTM systems in the serovar Lai show unique features which were eukaryotic-like. Comparative proteomic analysis between 56601 and IPAV strain revealed 1 627 pairs of orthologs, 174 genes in the IPAV strain were upregulated and 228 genes in strain 56601 were upregulated.Based on the genomic and proteomic studies, some genes were selected to be further studied  to confirm their potential function on pathogenesis, vaccine and diagnosis.

Key words: Leptospira interrogans, genomics, proteomics