Abstract: AI-2–mediated quorum sensing has been identified in various bacteria, including both Gram-negative and Gram-positive species, and numerous phenotypes have been reported to be regulated by this mechanism, using the luxS-mutant strain. But the AI-2 production process confused this regulatory function; some considered this regulation as the result of a metabolic change, which refers to an important metabolic cycle named activated methyl cycle (AMC), caused by luxS-mutant simultaneously with the defect of AI-2. Herein we hypothesized that the quorum sensing system—not the metabolic aspect—is responsible for such a regulatory function. In this study, we constructed plasmids infused with sahH and induced protein expression in the luxS-mutant strain to make the quorum-sensing system and metabolic system independent. The biofilm-related genes were investigated by real-time polymerase chain reaction (PCR), and the results demonstrated that the quorum-sensing completed strain restored the gene expression of the defective strain, but the metabolically completed one did not. This evidence supported our hypothesis that the autoinducer-2-mediated, quorum-sensing system, not the AMC, was responsible for luxS mutant regulation.
Keywords: quorum sensing; AI-2; luxS; sahH
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Wang, Q.; He, Z.; Hu, Y.; Jiang, Y.; Ma, R.; Tang, Z.; Liang, J.; Liu, Z.; Huang, Z. luxS Mutant Regulation: Quorum Sensing Impairment or Methylation Disorder? Sensors 2012, 12, 6176-6185.
Wang Q, He Z, Hu Y, Jiang Y, Ma R, Tang Z, Liang J, Liu Z, Huang Z. luxS Mutant Regulation: Quorum Sensing Impairment or Methylation Disorder? Sensors. 2012; 12(5):6176-6185.
Wang, Qian; He, Zhiyan; Hu, Yuejian; Jiang, Yuntao; Ma, Rui; Tang, Zisheng; Liang, Jingping; Liu, Zheng; Huang, Zhengwei. 2012. "luxS Mutant Regulation: Quorum Sensing Impairment or Methylation Disorder?" Sensors 12, no. 5: 6176-6185.