Identification of the RNA-binding domain-containing protein RbpA that acts as a global regulator of the pathogenicity of Streptococcus suis serotype 2

ABSTRACT

Streptococcus suis serotype 2 (SS2), an emerging zoonotic pathogen, causes swine diseases and human cases of streptococcal toxic shock syndrome. RNA-binding proteins (RBPs) can modulate gene expression through post-transcriptional regulation. In this study, we identified an RBP harbouring an S1 domain, named RbpA, which facilitated SS2 adhesion to host epithelial cells and contributed to bacterial pathogenicity. Comparative proteomic analysis identified 145 proteins that were expressed differentially between ΔrbpA strain and wild-type strain, including several virulence-associated factors, such as the extracellular protein factor (EF), SrtF pilus, IgA1 protease, SBP2 pilus, and peptidoglycan-binding LysM’ proteins. The mechanisms underlying the regulatory effects of RbpA on their encoding genes were explored, and it was found that RbpA regulates gene expression through diverse mechanisms, including post-transcriptional regulation, and thus acts as a global regulator. These results partly reveal the pathogenic mechanism mediated by RbpA, improving our understanding of the regulatory systems of S. suis and providing new insights into bacterial pathogenicity.

KEYWORDS:

• Streptococcus suis
• RNA-binding protein
• Rbpa
• pathogenicity
• post-transcriptional regulation

Acknowledgements

We are grateful to Dr. Pascale Romby from Architecture et Réactivité de l’ARN (UPR 9002), CNRS, for providing pLUG220 plasmid.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data generated or analysed during this study are included in this article and its supplementary information files. The proteomics raw data of this study have been deposited under the accession number IPX0003548002 at iProX.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/21505594.2022.2103233.

Additional information

Funding

This work was supported by the Development Program of Jiangsu Modern Agricultural Industry Technology System (No. JSTS[2018]011), Shanghai Agriculture Applied Technology Development Program (No. G2016060201), the Special Fund for Public Welfare Industry of Chinese Ministry of Agriculture (No. 201303041) and the project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).