Stetten Lecture videocast
Speaker: Bonnie L. Bassler, Ph.D.
Investigator, Howard Hughes Medical Institute
Squibb Professor of Molecular Biology
Not long ago, most biologists thought bacteria were asocial creatures. Now, it is clear that bacteria communicate within and between species using chemical languages that enable them to coordinately regulate gene expression and synchronize group behaviors.
Bacterial communication, called quorum sensing, is a census-taking process that allows bacteria to wait until they have achieved a critical cell number before embarking on processes such as virulence, biofilm formation, sporulation and mating. Quorum sensing processes are typically ones that are not effective if undertaken by a single bacterium acting alone but become successful when a group of cells acts in concert.
Bonnie Bassler has been studying quorum sensing for nearly 20 years. She and her coworkers have shown that bacteria are multi-lingual: They have unique languages for communicating within their own species, and they also possess a common language for communication between species. Bassler pioneered the idea that a basic life process in bacteria is sociality. Her theory has implications for human health, as bacterial quorum sensing is essential for a long list of infectious diseases. Strategies for interfering with quorum sensing, which Bassler’s lab is developing, could serve as alternatives to traditional antibiotics and possibly circumvent the growing problem of antibiotic resistance.
Primarily using the luminous bacterium Vibrio harveyi and the pathogen Vibrio cholerae, Bassler and her research team have discovered that quorum sensing involves bacteria secreting specific chemical signal molecules called autoinducers, each of which is detected by a specific sensor protein. Her group has identified the genes that allow signal production, detection and response in both Vibrio species, and they have shown that the signals are relayed within cells through phosphorylation and dephosphorylation cascades. Small regulatory RNAs act at the center of these cascades to create sensitive switches controlling the transitions into and out of quorum-sensing mode.
Bassler believes that insights gleaned from bacteria about chemical communication will ultimately shed light on how cells evolved to interact and carry out group behaviors in higher organisms, including humans.
Bassler is the Squibb Professor of Molecular Biology at Princeton University, where she has been a faculty member since 1994. She is also a Howard Hughes Medical Institute investigator and is slated to be president of the American Society for Microbiology in 2010. Bassler received a B.S. in biochemistry from the University of California, Davis, in 1984 and a Ph.D. in biochemistry from Johns Hopkins University in 1990. She was a postdoctoral fellow at the Agouron Institute in La Jolla, California, where she began studying quorum sensing.
Among Bassler’s many honors are a MacArthur Foundation Fellowship in 2002 and election to the National Academy of Sciences in 2006. She was made a fellow of the American Association for the Advancement of Science in 2004 and received the American Society for Microbiology’s Eli Lilly and Company Research Award for her fundamental contributions to microbiological research in 2006. Known as a dedicated teacher, Bassler received Princeton’s President’s Award for Distinguished Teaching in 2008 and was her department’s director of graduate studies for five years. She is currently its director for recruiting and diversity, and she heads Princeton’s Council on Science and Technology. Bassler serves as an editor for a number of journals, including Molecular Microbiology, Annual Reviews of Genetics and Cell. She is also a member of many grant, fellowship and award review panels.
NIGMS has supported Bassler’s research since 2002.