A systematic model of bacterial chemotaxis: from signal transduction to cell motility in Escherichia coli.
by
Xiangrong Xin
Department of Biomedical Engineering and School of Mathematics, University of Minnesota
Coauthors: David J. Odde, Department of Biomedical Engineering, University of Minnesota, Email: oddex002@umn.edu; Hans G. Othmer, School of Mathematics and Digital Technology Center, University of Minnesota, Email: othmer@math.umn.edu

The movement of bacteria in response to environmental changes of specific metabolites and signaling molecules is called bacterial chemotaxis. Chemotaxis in Escherichia coli (E. coli) is a best studied system. The authors will present a systematic model of E. coli chemotaxis that can capture many features of the system and reproduce a full range of experimental observations from signaling (excitation, perfect adaptation, robustness, high sensitivity, wide dynamic range, etc.) to motor behavior and cellular motility. A remarkable feature of the signaling pathway is its high sensitivity to small relative changes in concentrations of chemical stimuli over a broad range of ambient concentrations. To account for it, the signaling part of the model is based on the structural and functional unit of receptor clusters, ‘trimer of chemoreceptor dimers’, which has been solidly experimentally established but not well quantitatively modeled, so the theoretical work includes more molecular mechanism in modeling and provides a more mechanistically based description of the origin of high sensitivity than the existing models in the field.

Date received: May 15, 2008