for elucidating the molecular mechanism of quorum sensing, a process whereby bacteria communicate with each other and which offers innovative ways to interfere with bacterial pathogens or to modulate the microbiome for health applications.
The Shaw Prize in Life Science and Medicine 2015 is awarded to Bonnie L Bassler, Squibb Professor and Chair of the Department of Molecular Biology at Princeton University and an Investigator of the Howard Hughes Medical Institute, and E Peter Greenberg, Professor of Microbiology at the University of Washington, for elucidating the molecular mechanism of quorum sensing, a process whereby bacteria communicate with each other and which offers innovative ways to interfere with bacterial pathogens or to modulate the microbiome for health applications.
Bacteria used to be regarded as lonely individual cells that act independently from their neighbouring cells. Research in the past four decades has painted a completely different picture. Bacteria survive and thrive in communities in every imaginable habitat. In each community, bacteria communicate with each other and with other species to coordinate functions that are difficult or impossible to achieve by individual cells. These include uptake and processing of nutrients, coping with environmental stresses, and mounting attacks on host organisms. A ubiquitous bacterial communication strategy is quorum sensing, whereby bacterial cells sense and respond to changes in their local densities by the production and sensing of small, diffusible molecules. Bonnie L Bassler and E Peter Greenberg elucidated many of the molecular mechanisms underlying quorum sensing as well as the implications of the mechanism in controlling bacterial physiology in the context of infectious diseases. The phenomenon of quorum sensing has also been described in certain ants and honey bees. Recently, it has been identified in a mouse model concerning hair growth where the loss of one hair can stimulate hair growth in its neighbourhood.
As implied in the term single-cell organisms, bacteria used to be regarded as lonely individual cells that act independently from their neighbouring cells. Research in the past four decades has painted a completely different picture. Bacteria survive and thrive in communities in every imaginable habitat. In each community, bacteria communicate with each other and with other species to coordinate functions that are difficult or impossible to achieve by individual cells. These include uptake and processing of nutrients, coping with environmental stresses, and mounting attacks on host organisms. A ubiquitous bacterial communication strategy is quorum sensing, whereby bacterial cells sense and respond to changes in their local densities by the production and sensing of small, diffusible molecules. Bonnie L Bassler and E Peter Greenberg elucidated many of the molecular mechanisms underlying quorum sensing as well as the implications of the mechanism in controlling bacterial physiology in the context of infectious diseases. Understanding quorum sensing is of fundamental significance for explaining how bacteria interact with each other or with their physical environment. It points to innovative ways to interfere with bacterial pathogens or to modulate the microbiome for health applications, and establishes a technological foundation for precisely controlling bacterial dynamics using artificial gene circuits.
The recognition of quorum sensing and the elucidation of its underlying mechanism are one of the most fascinating developments in microbiology. The notion of bacterial cells communicating within and between species has transformed the way we think of bacteria or interpret the implications of gene regulatory mechanisms. While numerous quorum sensing systems have been discovered, they share the same fundamental architecture. Each cell produces a small molecule that is released into the environment by diffusion or excretion. The concentration of the molecule then reflects the density of the producing cells and can trigger gene expression in cells able to respond to this molecule, through a cognate receptor protein. This incredibly simple yet elegant mechanism enables bacteria to sense changes in their local densities or the physical confinement, and to coordinate behaviour within a population or between populations of the same or different species. It plays a critical role in controlling diverse functions, including generation of bioluminescence, formation of biofilms, and development of virulence. In addition to their roles in bacterial physiology, the molecular components underlying quorum sensing have been widely used in synthetic gene circuits to program dynamics of one or multiple bacterial populations in time and space.
Bonnie L Bassler was born in 1962 in Chicago, USA and is currently the Squibb Professor and Chair of the Department of Molecular Biology at Princeton University and an Investigator of the Howard Hughes Medical Institute, USA. She obtained her Bachelor of Science in Biochemistry from the University of California, Davis in 1984 and her PhD in Biochemistry from Johns Hopkins University in 1990. She was a Postdoctoral Fellow and a Research Scientist in The Agouron Institute, La Jolla, California, 1990–1993 and 1993–1994, respectively. She then joined Princeton University, where in the Department of Molecular Biology she was successively Assistant Professor (1994–2000), Associate Professor (2000–2003) and Professor (2003–). She has been elected to the US National Academy of Sciences and the American Academy of Arts and Sciences, and is a Foreign Member of the Royal Society of London.
E Peter Greenberg was born in 1948 in New York City, USA and is currently Professor of Microbiology at the University of Washington. He received his Bachelor’s degree in Biology from Western Washington University in 1970, his Master’s degree in Microbiology from the University of Iowa and his PhD in Microbiology from the University of Massachusetts. After a period of postdoctoral research at Harvard University, he joined the faculty at Cornell University and then the University of Iowa, before moving to the University of Washington in 2005. He has been elected to the US National Academy of Sciences and the American Academy of Arts and Sciences, the American Association for the Advancement of Sciences and the American Academy of Microbiology. He is widely credited for founding the quorum sensing field.
The research in Professor Greenberg’s laboratory is focused on the emerging field of sociomicrobiology. He has uncovered details about how individual bacteria communicate with each other to coordinate their activities. His work has impacted our understanding about the molecular basis of cooperation and about the importance of communication to the ecological success of bacterial species. His fundamental research has led to efforts to develop novel anti-infective therapeutics and to the development of other types of biotechnological applications.
