Staphylococcus aureus AI-2 quorum sensing associates with the KdpDE two-component system to regulate capsular polysaccharide synthesis and virulence.
Autoinducer 2 (AI-2) is widely recognized as a signal molecule for intra- and interspecies communication in Gram-negative bacteria, but its signaling function in Gram-positive bacteria, especially in Staphylococcus aureus, remains obscure. Here we reveal the role of LuxS in the regulation of capsular polysaccharide synthesis in S. aureus NCTC8325 and show that AI-2 can regulate gene expression and is involved in some physiological activities in S. aureus as a signaling molecule. Inactivation of luxS in S. aureus NCTC8325 resulted in higher levels of transcription of capsular polysaccharide synthesis genes. The survival rate of the luxS mutant was higher than that of the wild type in both human blood and U937 macrophages. In comparison to the luxS mutant, a culture supplemented with chemically synthesized 4,5-dihydroxy-2,3-pentanedione (DPD), the AI-2 precursor molecule, restored all the parental phenotypes, suggesting that AI-2 has a signaling function in S. aureus. Furthermore, we demonstrated that the LuxS/AI-2 signaling system regulates capsular polysaccharide production via a two-component system, KdpDE, whose function has not yet been clarified in S. aureus. This regulation occurred via the phosphorylation of KdpE binding to the cap promoter.
Zhao
Liping
L
Hefei National Laboratory for Physical Sciences at Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China.
Xue
Ting
T
Shang
Fei
F
Sun
Haipeng
H
Sun
Baolin
B
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001769:Blood / Q000382:microbiology; D013437:Carbon-Sulfur Lyases / Q000235:genetics; D002460:Cell Line; D015964:Gene Expression Regulation, Bacterial; D055786:Gene Knockout Techniques; D006714:Homoserine / Q000031:analogs & derivatives* / Q000378:metabolism; D006801:Humans; D007783:Lactones / Q000378:metabolism*; D008264:Macrophages / Q000382:microbiology; D050296:Microbial Viability; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D011494:Protein Kinases / Q000378:metabolism*; D053038:Quorum Sensing; D015398:Signal Transduction; D013211:Staphylococcus aureus / Q000378:metabolism / Q000472:pathogenicity*; D015534:Trans-Activators / Q000378:metabolism*; D014774:Virulence
D001426:Bacterial Proteins; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D011135:Polysaccharides, Bacterial; D015534:Trans-Activators; D006714:Homoserine; D011494:Protein Kinases; C075616:kdpD protein, Bacteria; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria