Bonnie L. Bassler
Election Year: 2006
Primary Section: 44, Microbial Biology
Secondary Section: 26, Genetics
Membership Type: Member
I investigate mechanisms of cell-to-cell communication in bacteria. This process, called quorum sensing, involves the production, release, and subsequent detection of chemical signaling molecules called autoinducers. Quorum sensing allows bacteria to synchronize behaviors and thereby function as multi-cellular organisms. Processes controlled by quorum sensing are usually ones that are unproductive when undertaken by an individual bacterium but become effective when undertaken by the group. For example, quorum sensing controls bioluminescence, secretion of virulence factors, biofilm formation, sporulation, and the exchange of DNA. Using the bioluminescent marine bacterium Vibrio harveyi and the related pathogenic bacterium Vibrio cholerae as models, we have shown that bacteria make, detect, and integrate information from multiple autoinducers, some of which are used exclusively for intra-species communication while one, called AI-2, appears to be a universal signal enabling inter-species communication. Our recent studies combining genetics and bioinformatics show that multiple small regulatory RNAs act at the core of quorum-sensing cascades, and function as ultrasensitive regulatory switches controlling the transition into and out of quorum-sensing mode. Currently, we are developing therapies that interfere with quorum sensing to control bacterial virulence. Specifically, AI-2 and its detection apparatus are promising targets for novel broad-spectrum anti-microbial drug design.