Robust perfect adaptation in bacterial chemotaxis through integral feedback control
AUTOR(ES)
Yi, Tau-Mu
FONTE
The National Academy of Sciences
RESUMO
Integral feedback control is a basic engineering strategy for ensuring that the output of a system robustly tracks its desired value independent of noise or variations in system parameters. In biological systems, it is common for the response to an extracellular stimulus to return to its prestimulus value even in the continued presence of the signal—a process termed adaptation or desensitization. Barkai, Alon, Surette, and Leibler have provided both theoretical and experimental evidence that the precision of adaptation in bacterial chemotaxis is robust to dramatic changes in the levels and kinetic rate constants of the constituent proteins in this signaling network [Alon, U., Surette, M. G., Barkai, N. & Leibler, S. (1998) Nature (London) 397, 168–171]. Here we propose that the robustness of perfect adaptation is the result of this system possessing the property of integral feedback control. Using techniques from control and dynamical systems theory, we demonstrate that integral control is structurally inherent in the Barkai–Leibler model and identify and characterize the key assumptions of the model. Most importantly, we argue that integral control in some form is necessary for a robust implementation of perfect adaptation. More generally, integral control may underlie the robustness of many homeostatic mechanisms.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=18287Documentos Relacionados
- The Control of the Controller: Molecular Mechanisms for Robust Perfect Adaptation and Temperature Compensation
- Adaptation kinetics in bacterial chemotaxis.
- Sensory adaptation in bacterial chemotaxis: regulation of demethylation.
- A model of excitation and adaptation in bacterial chemotaxis
- Novel sensory adaptation mechanism in bacterial chemotaxis to oxygen and phosphotransferase substrates.