Systematic protein interactome analysis of glycosaminoglycans revealed YcbS as a novel bacterial virulence factor.

Felix Shih-Hsiang Hsiao,Fx Reymond Sutandy,Jun-Mu Lin,Chien-Sheng Chen,Yi-Wen Chen,Guan-Da Syu

doi:10.1038/srep28425

Felix Shih-Hsiang Hsiao, Fx Reymond Sutandy + Show 4 more

Open Access

https://doi.org/10.1038/srep28425

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Journal: Scientific Reports	Publication Date: Jun 21, 2016
Citations: 14	License type: CC BY 4.0

Affiliation: National Central University

Abstract

Microbial pathogens have evolved several strategies for interacting with host cell components, such as glycosaminoglycans (GAGs). Some microbial proteins involved in host–GAG binding have been described; however, a systematic study on microbial proteome–mammalian GAG interactions has not been conducted. Here, we used Escherichia coli proteome chips to probe four typical mammalian GAGs, heparin, heparan sulphate (HS), chondroitin sulphate B (CSB), and chondroitin sulphate C (CSC), and identified 185 heparin-, 62 HS-, 98 CSB-, and 101 CSC-interacting proteins. Bioinformatics analyses revealed the unique functions of heparin- and HS-specific interacting proteins in glycine, serine, and threonine metabolism. Among all the GAG-interacting proteins, three were outer membrane proteins (MbhA, YcbS, and YmgH). Invasion assays confirmed that mutant E. coli lacking ycbS could not invade the epithelial cells. Introducing plasmid carrying ycbS complemented the invading defects at ycbS lacking E. coli mutant, that can be further improved by overexpressing ycbS. Preblocking epithelial cells with YcbS reduced the percentage of E. coli invasions. Moreover, we observed that whole components of the ycb operon were crucial for invasion. The displacement assay revealed that YcbS binds to the laminin-binding site of heparin and might affect the host extracellular matrix structure by displacing heparin from laminin.

Highlights

Some microbial virulence factors involved in host–GAG binding have been described; a systematic study on microbial proteome and mammalian GAG interactions has not been reported
We performed proteome-wide screening of the GAG interactome by using E. coli proteome chips
We used four typical mammalian GAGs labelled with DyLight 650, heparin, heparan sulphate (HS), chondroitin sulphate B (CSB), and chondroitin sulphate C (CSC) to profile the interactions of these molecules with the E. coli proteome

Summary

Introduction

Some microbial virulence factors involved in host–GAG binding have been described; a systematic study on microbial proteome and mammalian GAG interactions has not been reported. Several proteome microarrays have been fabricated, such as yeast[16], Escherichia coli[17], Arabidopsis[18], and human proteome microarrays[19,20]. These studies have recently been applied to various research areas, including protein– protein, protein–lipid, protein–DNA, protein–peptide, protein–cell, and protein–small molecule interactions[21]. We conducted a proteome-wide screening of the GAG interactome by using E. coli proteome chips containing approximately 4300 nonredundant proteins. We used four typical mammalian GAGs, namely heparin, HS, CSB, and CSC, to profile the interactions of these molecules with the E. coli proteome. YcbS was confirmed as a major molecule for bacterial infection

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Conclusion