Phys. Rev. Lett. 107, 178101 (2011) [5 pages]

Dynamics of Cooperativity in Chemical Sensing among Cell-Surface Receptors

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Monica Skoge1, Yigal Meir2, and Ned S. Wingreen3
1Department of Biology, University of California San Diego, San Diego, California 92037, USA
2Department of Physics, Ben-Gurion University, Beer Sheva, Israel 84105
3Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA

Received 3 May 2011; published 18 October 2011

Cooperative interactions among sensory receptors provide a general mechanism to increase the sensitivity of signal transduction. In particular, bacterial chemotaxis receptors interact cooperatively to produce an ultrasensitive response to chemoeffector concentrations. However, cooperativity between receptors in large macromolecular complexes is necessarily based on local interactions and consequently is fundamentally connected to slowing of receptor-conformational dynamics, which increases intrinsic noise. Therefore, it is not clear whether or under what conditions cooperativity actually increases the precision of the concentration measurement. We explicitly calculate the signal-to-noise ratio (SNR) for sensing a concentration change using a simple, Ising-type model of receptor-receptor interactions, generalized via scaling arguments, and find that the optimal SNR is always achieved by independent receptors.

© 2011 American Physical Society

87.16.Xa, 87.18.Tt, 87.18.Vf