Polyphosphate kinase 1 of Burkholderia pseudomallei controls quorum sensing, RpoS and host cell invasion

Kitima Srisanga; Praewa Suthapot; Permkun Permsirivisarn; Piyarat Govitrapong; Sumalee Tungpradabkul; Patompon Wongtrakoongate

doi:10.1016/j.jprot.2018.12.024

Polyphosphate kinase 1 of Burkholderia pseudomallei controls quorum sensing, RpoS and host cell invasion

J Proteomics. 2019 Mar 1:194:14-24. doi: 10.1016/j.jprot.2018.12.024. Epub 2018 Dec 28.

Authors

Kitima Srisanga¹, Praewa Suthapot¹, Permkun Permsirivisarn¹, Piyarat Govitrapong², Sumalee Tungpradabkul¹, Patompon Wongtrakoongate³

Affiliations

¹ Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand.
² Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok, Thailand.
³ Department of Biochemistry, Faculty of Science, Mahidol University, Bangkok, Thailand; Center for Neuroscience, Faculty of Science, Mahidol University, Bangkok, Thailand. Electronic address: patompon.won@mahidol.ac.th.

PMID: 30597312
DOI: 10.1016/j.jprot.2018.12.024

Abstract

Burkholderia pseudomallei is a Gram negative bacterium and the causative agent of melioidosis. Nonetheless, how virulence factors and pathogenic mechanisms are regulated have been elusive. In this study, we determined a role of polyphosphate kinase 1 (Ppk1) in regulation of quorum sensing (QS) and the sigma factor RpoS, and identified genes co-regulated by Ppk1, QS and RpoS. We find that Ppk1 positively controls autoinducer production and expression of rpoS transcript. Proteomic analysis identified 70 protein spots that are differentially expressed between B. pseudomallei wildtype and its ppk1-deficient strain. Within Ppk1regulated proteins, expression of 31 proteins are co-regulated by both RpoS and QS, whose functions of the majority of these proteins are associated with energy production and stress response. Moreover, expression of proteins involved in type III secretion system (T3SS) is also controlled by Ppk1. Quantitative PCR analysis confirmed that the T3SS genes bipB, bsaR and hrpK are down-regulated in ppk1 mutant. In addition, the ppk1-deficient strain exhibits defects in adhesion and invasion into human lung epithelial cells. Our work therefore reveals regulation of virulence factors and a regulatory mechanism of RpoS and QS by Ppk1, which altogether participate in gene expression control, and might be crucial for pathogenicity of B. pseudomallei. SIGNIFICANCE: Polyphosphate kinase1 (Ppk1), which is a key enzyme in polyphosphate biosynthesis, is pivotal for virulence of the melioidosis pathogen B. pseudomallei. This enzyme is not present in human. Therefore, it has been proposed to be a key target for anti-bacterial drugs. An important step toward development of novel antibiotics and therapeutic strategies is an analysis of proteins that are controlled by Ppk1. By using proteomics, we find that Ppk1 co-regulates virulence-associated genes together with quorum sensing (QS) and the sigma factor RpoS. Moreover, we reveal that Ppk1 is critical for bacterial adhesion and host cell invasion, supporting the finding from our proteome analysis.

Keywords: Burkholderia pseudomallei; Polyphosphate kinase 1; Quorum sensing; RpoS.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

A549 Cells
Bacterial Proteins* / genetics
Bacterial Proteins* / metabolism
Burkholderia pseudomallei* / genetics
Burkholderia pseudomallei* / metabolism
Burkholderia pseudomallei* / pathogenicity
Gene Expression Regulation, Bacterial*
Humans
Phosphotransferases (Phosphate Group Acceptor)* / genetics
Phosphotransferases (Phosphate Group Acceptor)* / metabolism
Quorum Sensing*
Sigma Factor* / genetics
Sigma Factor* / metabolism
Type III Secretion Systems* / genetics
Type III Secretion Systems* / metabolism

Substances

Bacterial Proteins
Sigma Factor
Type III Secretion Systems
sigma factor KatF protein, Bacteria
Phosphotransferases (Phosphate Group Acceptor)
polyphosphate kinase