Construction and evaluation of AgrA/C two component signal transduction model of Staphylococcus aureus

Abstract:

[Background] The abuse of antibiotics accelerated the emergence of antibiotic-resistant of Staphylococcus aureus, and the infections caused by these superbugs have become one of the most challenging tasks in clinic. Reconstruction of the transmembrane signal transduction process of AgrA/C pathway in vitro will be very helpful in solving the problem of antibiotic resistance in S. aureus and developing new antibiotics against these bacteria. [Objective] To realize in vitro construction of an AgrA/C two component signal transduction model for investigating mechanism of two component signal transduction in S. aureus and drug screening. [Methods] AgrA and AgrC proteins were expressed in Escherichia coli C43(DE3) and purified by affinity and size exclusion chromatography, and then their biological activities were analyzed. The AgrA/C two component signal transduction model was constructed in vitro using detergent-mediated method and the validity of the model was verified through the electrophoretic mobility shift assay (EMSA). [Results] The purity of AgrA and AgrC was over 90%. AgrA protein can bind to the target DNA and AgrC has the kinase activity. The AgrA/C two component signal transduction model was constructed in vitro. The model could enhance the delay of DNA mobility shift by AgrA, indicating the artificial simulation model can transfer signal. [Conclusion] we designed and constructed the AgrA/C two component signal transduction model in vitro successfully. This model system is expected to be a screening platform for new antibacterial drugs targeting S. aureus.

Key words:Staphylococcus aureus, AgrA/C two component signal transduction model, EMSA, Quorum sensing