Coordinate regulation of carbohydrate metabolism and virulence by PtsH in pathogen Edwardsiella piscicida

• Published in: Applied microbiology and biotechnology Vol. 106; no. 5-6; pp. 2063 - 2077
• Main Authors: Mao, Qiaoqiao, Jiang, Jihao, Wu, Xiao, Xu, Rongjing, Ma, Yue, Zhang, Yuanxing, Shao, Shuai, Wang, Qiyao
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.03.2022; Springer; Springer Nature B.V
• Subjects: Allosteric properties; Analysis; Applied Genetics and Molecular Biotechnology; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biomedical and Life Sciences; Biotechnology; Carbohydrate Metabolism; Carbohydrates; Composition; Deletion mutant; Edwardsiella; Edwardsiella piscicida; Enterobacter; Enterobacteriaceae; Enterobacteriaceae Infections - veterinary; Gene deletion; Gene expression; Genetic aspects; Humans; Identification and classification; Life Sciences; Mannose; Metabolism; Microbial Genetics and Genomics; Microbiology; Molecular modelling; N-Acetylgalactosamine; N-Acetylglucosamine; Pathogenesis; Pathogens; Phosphorylation; Phosphotransferase; Phosphotransferases; Properties; Saccharides; Substrates; Sugar; Type III Secretion Systems - genetics; Virulence; Virulence (Microbiology); China; Mannose; Type III secretion system (T3SS); Virulence; Phosphotransferase system; Edwardsiella piscicida
• DOI: 10.1007/s00253-022-11848-8
• ISSN: 0175-7598

Carbohydrate metabolism of bacterial pathogens conducts crucial roles in regulating pathogenesis but the molecular mechanisms by which metabolisms and virulence are been modulated and coordinated remain to be illuminated. Here, we investigated in this regard Edwardsiella piscicida , a notorious zoonotic pathogen previously named E. tarda that could ferment very few PTS sugars including glucose, fructose, mannose, N-acetylglucosamine, and N-acetylgalactosamine . We systematically characterized the roles of each of the predicted 23 components of phosphotransferase system (PTS) with the respective in-frame deletion mutants and defined medium containing specific PTS sugar. In addition, PtsH was identified as the crucial PTS component potentiating the utilization of all the tested PTS sugars. Intriguingly, we also found that PtsH while not Fpr was involved in T3SS gene expression and was essential for the pathogenesis of E. piscicida . To corroborate this, His15 and Ser46, the two established PtsH residues involved in phosphorylation cascade, showed redundant roles in regulating T3SS yields. Moreover, PtsH was shown to facilitate mannose uptake and transform it into mannose-6-phosphate, an allosteric substrate established to activate EvrA to augment bacterial virulence. Collectively, our observations provide new insights into the roles of PTS reciprocally regulating carbohydrate metabolism and virulence gene expression. Key points • PTS components’ roles for sugar uptake are systematically determined in Edwardsiella piscicida. • PtsH is involved in saccharides uptake and in the regulation of E. piscicida’s T3SS expression. • PtsH phosphorylation at His15 and Ser46 is essential for the T3SS expression and virulence.