QseB/QseC: a two-component system globally regulating bacterial behaviors

HighlightsQseB/QseC ensures normal bacterial life processes, and the strict content control of phosphorylated QseB is critical to the bacterial life cycle.QseB/QseC globally regulates bacterial infection processes of pathogens. Bacterial virulence, bacterial resistance to host immune responses, flagella-driven bacterial motility, and antibiotic resistance are all regulated by QseB/QseC. The presence or absence of qseBC has recently been shown to be directly indicative of the pathogenicity of an organism.QseB/QseC confers survival advantages to environmental bacteria in microbial environments and exhibits a functional difference among bacterial strains. Challenges to overcome are how to reveal the ecological significance and the evolutionary diversity of QseB/QseC.AbstractQseB/QseC is a two-component system that is involved in the regulation of multiple bacterial behaviors by regulating quorum sensing, bacterial pathogenicity, and antibiotic resistance. Thus, QseB/QseC could provide a target for new antibiotic development. Recently, QseB/QseC has been found to confer survival advantages to environmental bacteria under stress conditions. The molecular mechanistic understanding of QseB/QseC has become an active area of research and revealed some emerging themes, including a deeper understanding of QseB/QseC regulation in different pathogens and environmental bacteria, the functional difference of QseB/QseC among species, and the possibility of analyzing QseB/QseC evolution. Here, we discuss the progression of QseB/QseC studies and describe several unresolved issues and future directions. Resolving these issues is among the challenges of future QseB/QseC studies.