title: Phosphoproteome analysis of the pathogenic bacterium Helicobacter pylori reveals over-representation of tyrosine phosphorylation and multiply phosphorylated proteins.
abstract: Increasing evidence shows that protein phosphorylation on serine (Ser), threonine (Thr) and tyrosine (Tyr) residues is a major regulatory post-translational modification in the bacteria. To reveal the phosphorylation state in the Gram-negative pathogenic bacterium Helicobacter pylori, we carried out a global and site-specific phosphoproteomic analysis based on TiO(2) -phosphopeptide enrichment and high-accuracy LC-MS/MS determination. Eighty-two phosphopeptides from 67 proteins were identified with 126 phosphorylation sites, among which 79 class I sites were determined to have a distribution of 42.8:38.7:18.5% for the Ser/Thr/Tyr phosphorylation, respectively. The H. pylori phosphoproteome is characterized by comparably big size, high ratio of Tyr phosphorylation, high abundance of multiple phosphorylation sites in individual phosphopeptides and over-representation of membrane proteins. An interaction network covering 28 phosphoproteins was constructed with a total of 163 proteins centering on the major H. pylori virulence factor VacA, indicating that protein phosphorylation in H. pylori may be delicately controlled to regulate many aspects of the metabolic pathways and bacterial virulence.
authors.affiliation: The Laboratory of Integrative Biosciences, College of Life Sciences, Sun Yat-Sen University, Guangzhou, P. R. China. gerg@mail.sysu.edu.cn
authors.forename: Ruiguang
authors.initials: R
authors.lastname: Ge
authors.forename: Xuesong
authors.initials: X
authors.lastname: Sun
authors.forename: Chuanle
authors.initials: C
authors.lastname: Xiao
authors.forename: Xingfeng
authors.initials: X
authors.lastname: Yin
authors.forename: Weiran
authors.initials: W
authors.lastname: Shan
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Chen
authors.forename: Qing-Yu
authors.initials: QY
authors.lastname: He
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis / Q000737:chemistry; D002853:Chromatography, Liquid; D016480:Helicobacter pylori / Q000737:chemistry* / Q000378:metabolism; D013058:Mass Spectrometry; D010748:Phosphopeptides / Q000032:analysis* / Q000378:metabolism; D010750:Phosphoproteins / Q000032:analysis* / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000032:analysis* / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism; D020543:Proteome / Q000032:analysis* / Q000378:metabolism; D040901:Proteomics
chemical_list: D001426:Bacterial Proteins; D010748:Phosphopeptides; D010750:Phosphoproteins; D020543:Proteome; C074689:VacA protein, Helicobacter pylori; D019000:Phosphotyrosine; D011494:Protein Kinases