title: Maxwell's demon in biochemical signal transduction with feedback loop.
abstract: Signal transduction in living cells is vital to maintain life itself, where information transfer in noisy environment plays a significant role. In a rather different context, the recent intensive research on 'Maxwell's demon'-a feedback controller that utilizes information of individual molecules-have led to a unified theory of information and thermodynamics. Here we combine these two streams of research, and show that the second law of thermodynamics with information reveals the fundamental limit of the robustness of signal transduction against environmental fluctuations. Especially, we find that the degree of robustness is quantitatively characterized by an informational quantity called transfer entropy. Our information-thermodynamic approach is applicable to biological communication inside cells, in which there is no explicit channel coding in contrast to artificial communication. Our result could open up a novel biophysical approach to understand information processing in living systems on the basis of the fundamental information-thermodynamics link.
authors.affiliation: Department of Physics, The University of Tokyo, Tokyo 113-0033, Japan.
authors.forename: Sosuke
authors.initials: S
authors.lastname: Ito
authors.affiliation: Department of Basic Science, The University of Tokyo, Tokyo 153-8902, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Sagawa
mesh_terms: D001426:Bacterial Proteins; D002633:Chemotaxis; D019277:Entropy; D004926:Escherichia coli; D029968:Escherichia coli Proteins; D025461:Feedback, Physiological; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; D008962:Models, Theoretical; D015398:Signal Transduction; D013816:Thermodynamics
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D000072236:Methyl-Accepting Chemotaxis Proteins; C069656:CheB protein, Bacteria