Comparative proteogenomic analysis of the Leptospira interrogans virulence-attenuated strain IPAV against the pathogenic strain 56601

Abstract

The virulence-attenuated Leptospira interrogans serovar Lai strain IPAV was derived by prolonged laboratory passage from a highly virulent ancestral strain isolated in China. We studied the genetic variations of IPAV that render it avirulent via comparative analysis against the pathogenic L. interrogans serovar Lai strain 56601. The complete genome sequence of the IPAV strain was determined and used to compare with, and then rectify and reannotate the genome sequence of strain 56601. Aside from their highly similar genomic structure and gene order, a total of 33 insertions, 53 deletions and 301 single-nucleotide variations (SNVs) were detected throughout the genome of IPAV directly affecting 101 genes, either in their 5′ upstream region or within their coding region. Among them, the majority of the 44 functional genes are involved in signal transduction, stress response, transmembrane transport and nitrogen metabolism. Comparative proteomic analysis based on quantitative liquid chromatography (LC)-MS/MS data revealed that among 1 627 selected pairs of orthologs, 174 genes in the IPAV strain were upregulated, with enrichment mainly in classes of energy production and lipid metabolism. In contrast, 228 genes in strain 56601 were upregulated, with the majority enriched in the categories of protein translation and DNA replication/repair. The combination of genomic and proteomic approaches illustrated that altered expression or mutations in critical genes, such as those encoding a Ser/Thr kinase, carbon-starvation protein CstA, glutamine synthetase, GTP-binding protein BipA, ribonucleotidediphosphate reductase and phosphate transporter, and alterations in the translational profile of lipoproteins or outer membrane proteins are likely to account for the virulence attenuation in strain IPAV.

Extracellular Proteome Analysis ofLeptospira interrogansserovar Lai

“…Of these 3718 CDSs, 2158 can be detected in the high-accuracy tandem mass spectrometry (MS/MS) spectra obtained by the Yin-yang multidimensional liquid chromatography (MDLC) system coupled to an LTQ-Orbitrap mass spectrometer (Cao et al, 2010). Based on the genomic and proteomic data available for L. interrogans (Cao et al, 2010;Zhong et al, 2011), we performed an in silico analysis of the secretion machinery components of L. interrogans serovar Lai. BLASTP search for homologs of components of the secretion systems of type I, type II, type III, type IV, type V, and type VI (Cao et al, 2010;Hayes et al, 2010;Ren et al, 2003) in the NCBI database revealed presence of many secretion-related genes in the L. interrogans genome.…”

“…The genome sequence of L. interrogans serovar Lai was completed in 2003, and the corresponding 4727 protein-coding sequences (CDSs) are available in GenBank (Ren et al, 2003). It was reannotated based on whole proteomics data, reducing the number of proteincoding sequences to 3718 CDSs (Zhong et al, 2011). Of these 3718 CDSs, 2158 can be detected in the high-accuracy tandem mass spectrometry (MS/MS) spectra obtained by the Yin-yang multidimensional liquid chromatography (MDLC) system coupled to an LTQ-Orbitrap mass spectrometer (Cao et al, 2010).…”

“…L. interrogans serovar Lai is a gram-negative bacteria that possesses an inner membrane and outer membrane. Based on the genomic and proteomic data available for L. interrogans (Cao et al, 2010;Zhong et al, 2011), BLASTP was used to search for homologs of components of the secretion system of T1SS, T2SS, T3SS, T4SS, T5SS, and T6SS in the NCBI in the L. interrogans genome and further to confirm the expression of the components by whole cell proteomics data search. This figure shows the schematic of a relatively complete T1SS and T2SS and incomplete T3SS, T4SS, T5SS, and T6SS in L. interrogans serovar Lai.…”

“…Now, another six strains of Leptospira have been sequenced (Bulach et al, 2006;Nascimento et al, 2004;Picardeau et al, 2008;Zhong et al, 2011), and draft sequences for more than one hundred strains have been deposited in GenBank. These studies have greatly facilitated our knowledge of Leptospira physiology and pathology at the genomic, transcriptomic (Hesterlee, 2001), and proteomic levels (Adler et al, 2011).…”

Avaliação da atividade imunogênica de três proteínas de Leptospira interrogans expressas em Escherichia coli.

“…(NASCIMENTO et al, 2004a, b;ZHONG et al, 2011). As linhagens de L. borgpetersenii sorovar Hadjo-bovis sequenciadas são L550 e JB197 .…”