Bonnie Bassler, "Manipulating Quorum Sensing to Control Bacterial Pathogenicity", VWR Distinguished Seminar in Experimental Biology and Joint Seminar with the School of Biology Seminar Series

Mar 31 2011, 11:00 am
Distinguished Lecture Series Guest Speaker: 

Bonnie Bassler

Howard Hughes Medical Institute investigator
Professor, Department of Molecular Biology
Princeton University

Date & Time: 
Thursday, March 31, 2011, 11:00AM
Marus Nanotechnology Building, Room 1116
Brian Hammer
Bacteria communicate with one another via the production and detection of secreted signal molecules called autoinducers. This cell-to-cell communication process, called “Quorum Sensing”, allows bacteria to synchronize behavior on a population-wide scale. Behaviors controlled by quorum sensing are usually ones that are unproductive when undertaken by an individual bacterium acting alone but become effective when undertaken in unison by the group. For example, quorum sensing controls virulence, biofilm formation, sporulation, and the exchange of DNA. Thus, quorum sensing is a mechanism that allows bacteria to function as multi-cellular organisms. Gram-negative bacteria use acyl-homoserine lactone (AHL) autoinducers, which are detected by one of two receptor types, cytoplasmic LuxR-type receptors or membrane-bound LuxN-type receptors. We found small molecule antagonists of LuxN-type receptors that are also potent antagonists of LuxR-type receptors, despite differences in receptor structure, localization, AHL specificity, and signaling mechanism. Structural studies combined with mutagenesis allowed us to pinpoint the amino acid residues in the receptors that are critical for conferring agonist and antagonist activity to different ligands. Our most potent quorum-sensing antagonist protects animals from quorum-sensing-mediated killing by pathogenic bacteria validating the notion that targeting quorum sensing has potential for antimicrobial drug development.
Additional Info: 

Dr. Bassler's lab wants to understand quorum sensing: the process of cell-cell communication in bacteria. Quorum sensing involves the production, release, and subsequent detection of chemical signal molecules called autoinducers. This process enables populations of bacteria to regulate gene expression, and therefore behavior, on a community-wide scale. Quorum sensing is wide-spread in the bacterial world, so understanding this process is fundamental to all of microbiology, including industrial and clinical microbiology, and ultimately to understanding the development of higher organisms. Her labs studies of quorum sensing is providing insight into intra- and inter-species communication, population-level cooperation, and the design principles underlying signal transduction and information processing at the cellular level. These investigations are also leading to synthetic strategies for controlling quorum sensing. Our objectives include development of anti-microbial drugs aimed at bacteria that use quorum sensing to control virulence, and improved industrial production of natural products such as antibiotics. They have pursued our goal of understanding bacterial communication by combining genetics, biochemistry, structural biology, chemistry, microarray studies, bioinformatics, modeling, and engineering approaches.
Faculty Website
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