Related Experiment Video
Updated: Jan 22, 2026
Genotyping of Staphylococcus aureus by Ribosomal Spacer PCR RS-PCR
Published on: November 4, 2016
The dimerization interface in VraR is essential for induction of the cell wall stress response in Staphylococcus
Ghazal Tajbakhsh1, Dasantila Golemi-Kotra2
1Department of Biology, York University, Toronto, ON, M3J1P3, Canada.
Background:
Staphylococcus aureus remains a medical challenge in the treatment of bacterial infections. It has acquired resistance to commonly used antibiotics, and to those considered to be the last weapons in treating staphylococcal infections, such as vancomycin. Studies have revealed that S. aureus is capable of mounting a rapid response to antibiotics that target cell wall peptidoglycan biosynthesis, such as β-lactams and vancomycin. The two-component system VraSR has been linked to the coordination of this response. VraS is a histidine kinase that undergoes autophosphorylation in the presence of signals elicited upon cell wall damage and it then transfers its phosphoryl group to VraR. VraR is a response regulator protein that functions as a transcription factor. Phosphorylation of VraR leads to its dimerization, which is required for optimum binding to its target promoters. Two-component systems have been targeted for the development of antibacterial agents. Deletion of the vraS or vraR gene has been shown to re-sensitize S. aureus to β-lactams and vancomycin.
Results:
In this study, we explored perturbation of the VraR phosphorylation-induced activation as a means to inhibit the VraSR-mediated signal transduction pathway. We show that dimerization of VraR is essential for the phosphorylation-induced activation of VraR. A single point mutation in the dimerization interface of VraR, in which Met13 was replaced by Ala, led to the inability of VraR to dimerize and to bind optimally to the target promoter. The consequences of these in vitro molecular deficiencies are equally dramatic in vivo. Complementation of a vraR deletion S. aureus strain with the vraRM13Ala mutant gene failed to induce the cell wall stress response.
Conclusions:
This study highlights the potential of targeting the phosphorylation-induced dimerization of VraR to disrupt the S. aureus cell wall stress response and in turn to re-sensitize S. aureus to β-lactams and vancomycin.
Insights
Targeting Staphylococcus aureus VraR dimerization disrupts its cell wall stress response. This approach re-sensitizes bacteria to antibiotics like vancomycin, offering new treatment strategies for resistant infections.
Area of Science:
- Microbiology
- Molecular Biology
- Drug Discovery
Background:
- Staphylococcus aureus exhibits resistance to antibiotics, including vancomycin.
- The VraSR two-component system regulates S. aureus response to cell wall damage.
- VraR, a transcription factor, dimerizes upon phosphorylation to activate target promoters.
Purpose of the Study:
- To investigate VraR phosphorylation-induced dimerization as a target to inhibit the VraSR pathway.
- To assess the impact of disrupting VraR dimerization on S. aureus antibiotic resistance.
Main Methods:
- Explored perturbation of VraR phosphorylation-induced activation.
- Introduced a point mutation (Met13Ala) in VraR's dimerization interface.
- Assessed VraR dimerization, promoter binding, and cell wall stress response in vitro and in vivo.
Main Results:
- VraR dimerization is essential for its phosphorylation-induced activation.
- The M13A mutation prevented VraR dimerization and optimal promoter binding.
- Complementation with the mutated VraR failed to induce the cell wall stress response in a vraR deletion strain.
Conclusions:
- Targeting VraR phosphorylation-induced dimerization can disrupt S. aureus cell wall stress response.
- This strategy holds potential for re-sensitizing S. aureus to beta-lactams and vancomycin.
- Disrupting VraR dimerization offers a novel approach to combat antibiotic resistance.
Related Concept Videos
02:45Responses to Heat and Cold Stress
02:02Responses to Salt Stress
02:43Plant Cell Wall
01:07Plant Cell Wall
01:22Target Cell Response to Hormones
Notably, the cellular response can be regulated by altering the number of receptors expressed in the cell. For example, prolonged exposure to elevated hormone levels results in a gradual decline or down-regulation in the number of receptors for that specific hormone on the cell surface. Conversely, in response to low hormone levels, cells may use up-regulation, producing an...
01:21Stress Response System
Alarm stage
In the alarm stage, the body's...