The role of the lux autoinducer in regulating luminescence in Vibrio harveyi; control of luxR expression

Authors

  • Carol M. Miyamoto,

    1. Department of Biochemistry, Room 813, McIntyre Medical Sciences Building, McGill University, 3655 Drummond Street, Montreal, Quebec, Canada H3G 1Y6
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  • Jaidip Chatterjee,

    1. Department of Biochemistry, Room 813, McIntyre Medical Sciences Building, McGill University, 3655 Drummond Street, Montreal, Quebec, Canada H3G 1Y6
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  • Elana Swartzman,

    1. Department of Biochemistry, Room 813, McIntyre Medical Sciences Building, McGill University, 3655 Drummond Street, Montreal, Quebec, Canada H3G 1Y6
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    • Rose Szittner,

      1. Department of Biochemistry, Room 813, McIntyre Medical Sciences Building, McGill University, 3655 Drummond Street, Montreal, Quebec, Canada H3G 1Y6
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    • Edward A. Meighen

      1. Department of Biochemistry, Room 813, McIntyre Medical Sciences Building, McGill University, 3655 Drummond Street, Montreal, Quebec, Canada H3G 1Y6
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    Edward A. Meighen Tel. (514) 3987272; Fax (514) 3987384

    Abstract

    Analysis of Vibrio harveyi dark autoinducer mutants has demonstrated that the level of LuxR was much lower than that observed in wild-type cells. Complementation with luxR fully restored luminescence suggesting that the lux autoinducer may control expression of the luxR regulatory gene. By primer extension, the transcriptional start site of luxR was located 78 bp from the initiation codon. The level of the primer-extended product was enhanced upon addition of the lux autoinducer to the autoinducer mutants, which was confirmed by hybridization of lux mRNA with specific probes. By using chloramphenicol acetyltransferase as a reporter gene in a transcriptional fusion with luxR, the stimulatory effect of autoinducer on luxR expression was shown to occur at the level of the luxR promoter. The results provide evidence that the autoinducer signal in V. harveyi can be transduced through luxR, resulting in stimulation of luminescence.

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