Abstract
We present here the analytical relation between the gain of eukaryotic gradient sensing network and the associated thermodynamic cost. By analyzing a general incoherent type-1 feed-forward loop, we derive the gain function through the reaction network and explicitly show that depends on the nonequilibrium factor ( with and 1 representing irreversible and equilibrium reaction systems, respectively), the Michaelis constant , and the turnover ratio () of the participating enzymes. We further find the maximum possible gain is intrinsically determined by . Our model also indicates that the dissipated energy (measured by ), from the intracellular energy-bearing bioparticles (e.g., ATP), is used to generate a force field that reshapes and disables the effective potential around the zero gain region, which leads to the ultrasensitive response to external chemical gradients.
- Received 22 April 2015
DOI:https://doi.org/10.1103/PhysRevE.92.032702
©2015 American Physical Society