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Updated: Jul 10, 2026
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Quantifying Yersinia pseudotuberculosis Type III Secretion System Activity Following Iron Starvation and Anaerobic Growth
Published on: May 31, 2024
Environmental stimuli affecting expression of the Ysa type three secretion locus
Shirly Mildiner-Earley1, Kimberly A Walker, Virginia L Miller
1Molecular Microbiology ,Washington University, St. Louis, MO, USA.
Advances in Experimental Medicine and Biology
|October 31, 2007
Summary
Yersinia enterocolitica
Area of Science:
- Microbiology
- Bacterial Pathogenesis
- Molecular Biology
Background:
- Yersinia enterocolitica possesses two type III secretion systems (TTSS): the Ysc-Yop and the Ysa-Ysp systems.
- Ysa-Ysp system expression is typically observed in vitro under specific conditions: low temperature (26°C) and high salt (290mM NaCl).
- Previous studies indicated high salt activates ysaE promoter expression.
Purpose of the Study:
- To identify novel environmental stimuli that regulate Ysa-Ysp system expression in Yersinia enterocolitica.
- To investigate the role of growth substrate in modulating ysa gene expression.
Main Methods:
- Quantitative analysis of Ysp secretion under varying growth conditions.
- Comparison of gene expression levels between solid surface and broth cultures.
- Utilizing Yersinia enterocolitica grown in high-salt media.
Main Results:
- Growth on a solid surface significantly enhances Ysa-Ysp system expression (7-fold increase) compared to high-salt broth culture.
- Solid surface acts as a potent environmental signal for the Ysa system, particularly in the presence of salt.
- This finding expands the known regulatory factors influencing TTSS expression in Yersinia enterocolitica.
Conclusions:
- Solid surface is a robust environmental cue for Ysa-Ysp system activation in Yersinia enterocolitica, especially under high-salt conditions.
- This discovery provides new insights into the environmental regulation of bacterial secretion systems.
- Further research can explore the mechanisms underlying surface-mediated Ysa-Ysp expression.
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