Quantifying the entropic cost of cellular growth control Journal Article

Author(s): De Martino, Daniele; Capuani, Fabrizio; De Martino, Andrea
Article Title: Quantifying the entropic cost of cellular growth control
Affiliation IST Austria
Abstract: Viewing the ways a living cell can organize its metabolism as the phase space of a physical system, regulation can be seen as the ability to reduce the entropy of that space by selecting specific cellular configurations that are, in some sense, optimal. Here we quantify the amount of regulation required to control a cell's growth rate by a maximum-entropy approach to the space of underlying metabolic phenotypes, where a configuration corresponds to a metabolic flux pattern as described by genome-scale models. We link the mean growth rate achieved by a population of cells to the minimal amount of metabolic regulation needed to achieve it through a phase diagram that highlights how growth suppression can be as costly (in regulatory terms) as growth enhancement. Moreover, we provide an interpretation of the inverse temperature β controlling maximum-entropy distributions based on the underlying growth dynamics. Specifically, we show that the asymptotic value of β for a cell population can be expected to depend on (i) the carrying capacity of the environment, (ii) the initial size of the colony, and (iii) the probability distribution from which the inoculum was sampled. Results obtained for E. coli and human cells are found to be remarkably consistent with empirical evidence.
Journal Title: Physical Review E Statistical Nonlinear and Soft Matter Physics
Volume: 96
Issue 1
ISSN: 1539-3755
Publisher: American Institute of Physics  
Date Published: 2017-07-10
Start Page: Article Number: 010401
DOI: 10.1103/PhysRevE.96.010401
Open access: yes (repository)