2. Academic Validation
  3. A link between STK signalling and capsular polysaccharide synthesis in Streptococcus suis

A link between STK signalling and capsular polysaccharide synthesis in Streptococcus suis

  • Nat Commun. 2023 Apr 29;14(1):2480. doi: 10.1038/s41467-023-38210-4.
Jinsheng Tang 1,  Mengru Guo 1,  Min Chen 1,  Bin Xu 2,  Tingting Ran 3,  Weiwu Wang 3,  Zhe Ma 1 4,  Huixing Lin 1 4,  Hongjie Fan 5 6
Affiliations

Affiliations

  • 1 MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China.
  • 2 National Research Center of Veterinary Biologicals Engineering and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing, 210000, China.
  • 3 Department of Microbiology, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
  • 4 Jiangsu Coinnovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China.
  • 5 MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, 210095, China. fhj@njau.edu.cn.
  • 6 Jiangsu Coinnovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, 225009, China. fhj@njau.edu.cn.
PMID: 37120581 DOI: 10.1038/s41467-023-38210-4
Abstract

Synthesis of capsular polysaccharide (CPS), an important virulence factor of pathogenic bacteria, is modulated by the CpsBCD phosphoregulatory system in Streptococcus. Serine/threonine kinases (STKs, e.g. Stk1) can also regulate CPS synthesis, but the underlying mechanisms are unclear. Here, we identify a protein (CcpS) that is phosphorylated by Stk1 and modulates the activity of Phosphatase CpsB in Streptococcus suis, thus linking Stk1 to CPS synthesis. The crystal structure of CcpS shows an intrinsically disordered region at its N-terminus, including two threonine residues that are phosphorylated by Stk1. The activity of Phosphatase CpsB is inhibited when bound to non-phosphorylated CcpS. Thus, CcpS modulates the activity of Phosphatase CpsB thereby altering CpsD phosphorylation, which in turn modulates the expression of the Wzx-Wzy pathway and thus CPS production.

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