Related Experiment Videos
DsbA is required for stable expression of outer membrane protein YscC and for efficient Yop secretion in Yersinia
1Department of Microbiology and Immunology, University of Miami School of Medicine, Miami, Florida 33176, USA.
Abstract:
The role of the periplasmic disulfide oxidoreductase DsbA in Yop secretion was investigated in Yersinia pestis. A Y. pestis dsbA mutant secreted reduced amounts of the V antigen and Yops and expressed reduced amounts of the full-sized YscC protein. Site-directed mutagenesis of the four cysteine residues present in the YscC protein resulted in defects similar to those found in the dsbA mutant. These results suggest that YscC contains at least one disulfide bond that is essential for the function of this protein in Yop secretion.
Insights
The periplasmic disulfide oxidoreductase DsbA is crucial for Yersinia pestis virulence. DsbA and YscC protein disulfide bonds are essential for Yop secretion and V antigen export.
Area of Science:
- Microbiology
- Molecular Biology
- Protein Biochemistry
Background:
- Yersinia pestis is a Gram-negative bacterium responsible for plague.
- Yop secretion is mediated by a type III secretion system (T3SS).
- The periplasmic disulfide oxidoreductase DsbA is involved in protein folding and secretion.
Purpose of the Study:
- To investigate the role of DsbA in Yop secretion in Yersinia pestis.
- To determine if disulfide bonds in YscC are essential for Yop secretion.
Main Methods:
- Construction and analysis of a Y. pestis dsbA mutant.
- Site-directed mutagenesis of cysteine residues in YscC.
- Assessment of V antigen and Yop secretion levels.
- Analysis of YscC protein expression.
Main Results:
- A dsbA mutant exhibited reduced secretion of V antigen and Yops.
- The dsbA mutant showed reduced expression of full-sized YscC.
- Mutagenesis of YscC cysteine residues mimicked the dsbA mutant phenotype.
- These findings indicate YscC requires disulfide bonds for function.
Conclusions:
- DsbA plays a significant role in Yop secretion in Yersinia pestis.
- Disulfide bonds within YscC are critical for its function in the T3SS.
- The DsbA-mediated disulfide bond formation in YscC is essential for Yop secretion.