@article{90516, keywords = {Protein Structure, Tertiary, Bacterial Proteins, Molecular Sequence Data, Quorum Sensing, Vibrio, 4-Butyrolactone, Protein Kinases, Transcription Factors, Mutagenesis, Site-Directed, Acyl-Butyrolactones, Amino Acid Sequence}, author = {Lee Swem and Danielle Swem and Ned Wingreen and Bonnie Bassler}, title = {Deducing receptor signaling parameters from in vivo analysis: LuxN/AI-1 quorum sensing in Vibrio harveyi.}, abstract = { 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. }, year = {2008}, journal = {Cell}, volume = {134}, pages = {461-73}, month = {08/2008}, issn = {1097-4172}, doi = {10.1016/j.cell.2008.06.023}, language = {eng}, }