AUTHOR=Zhang Chunyan , Sun Wen , Tan Meifang , Dong Mengmeng , Liu Wanquan , Gao Ting , Li Lu , Xu Zhuofei , Zhou Rui 

TITLE=The Eukaryote-Like Serine/Threonine Kinase STK Regulates the Growth and Metabolism of Zoonotic Streptococcus suis

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=7

YEAR=2017

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2017.00066

DOI=10.3389/fcimb.2017.00066

ISSN=2235-2988

ABSTRACT=<p>Like eukaryotes, bacteria express one or more serine/threonine kinases (STKs) that initiate diverse signaling networks. The STK from <italic>Streptococcus suis</italic> is encoded by a single-copy <italic>stk</italic> gene, which is crucial in stress response and virulence. To further understand the regulatory mechanism of STK in <italic>S. suis</italic>, a <italic>stk</italic> deletion strain (Δ<italic>stk</italic>) and its complementary strain (CΔ<italic>stk</italic>) were constructed to systematically decode STK characteristics by applying whole transcriptome RNA sequencing (RNA-Seq) and phosphoproteomic analysis. Numerous genes were differentially expressed in Δ<italic>stk</italic> compared with the wild-type parental strain SC-19, including 320 up-regulated and 219 down-regulated genes. Particularly, 32 virulence-associated genes (VAGs) were significantly down-regulated in Δ<italic>stk</italic>. Seven metabolic pathways relevant to bacterial central metabolism and translation are significantly repressed in Δ<italic>stk</italic>. Phosphoproteomic analysis further identified 12 phosphoproteins that exhibit differential phosphorylation in Δ<italic>stk</italic>. These proteins are associated with cell growth and division, glycolysis, and translation. Consistently, phenotypic assays confirmed that the Δ<italic>stk</italic> strain displayed deficient growth and attenuated pathogenicity. Thus, STK is a central regulator that plays an important role in cell growth and division, as well as <italic>S. suis</italic> metabolism.</p>