The Eukaryote-Like Serine/Threonine Kinase STK Regulates the Growth and Metabolism of Zoonotic .

Like eukaryotes, bacteria express one or more serine/threonine kinases (STKs) that initiate diverse signaling networks. The STK from is encoded by a single-copy gene, which is crucial in stress response and virulence. To further understand the regulatory mechanism of STK in , a deletion strain (Δ) and its complementary strain (CΔ) 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 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. Seven metabolic pathways relevant to bacterial central metabolism and translation are significantly repressed in Δ. Phosphoproteomic analysis further identified 12 phosphoproteins that exhibit differential phosphorylation in Δ. These proteins are associated with cell growth and division, glycolysis, and translation. Consistently, phenotypic assays confirmed that the Δ 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 metabolism.