Deducing receptor signaling parameters from in vivo analysis: LuxN/AI-1 quorum sensing in Vibrio harveyi.
Quorum sensing, a process of bacterial cell-cell communication, relies on production, detection, and response to autoinducer signaling molecules. LuxN, a nine-transmembrane domain protein from Vibrio harveyi, is the founding example of membrane-bound receptors for acyl-homoserine lactone (AHL) autoinducers. We used mutagenesis and suppressor analyses to identify the AHL-binding domain of LuxN and discovered LuxN mutants that confer both decreased and increased AHL sensitivity. Our analysis of dose-response curves of multiple LuxN mutants pins these inverse phenotypes on quantifiable opposing shifts in the free-energy bias of LuxN for occupying its kinase and phosphatase states. To understand receptor activation and to characterize the pathway signaling parameters, we exploited a strong LuxN antagonist, one of fifteen small-molecule antagonists we identified. We find that quorum-sensing-mediated communication can be manipulated positively and negatively to control bacterial behavior and, more broadly, that signaling parameters can be deduced from in vivo data.
Swem
Lee R
LR
Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
Swem
Danielle L
DL
Wingreen
Ned S
NS
Bassler
Bonnie L
BL
D015107:4-Butyrolactone / Q000031:analogs & derivatives* / Q000378:metabolism; D054742:Acyl-Butyrolactones / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011494:Protein Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D053038:Quorum Sensing; D014157:Transcription Factors / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D014733:Vibrio / Q000737:chemistry* / Q000378:metabolism*
D054742:Acyl-Butyrolactones; D001426:Bacterial Proteins; D014157:Transcription Factors; C030654:N-(3-oxohexanoyl)-3-aminodihydro-2(3H)-furanone; D011494:Protein Kinases; C084290:luxN protein, Vibrio harveyi; D015107:4-Butyrolactone