Inoue, Masayo, and Kunihiko Kaneko. “Weber’s Law in Autocatalytic Reaction Networks” Seibutsu Butsuri 51, no. supplement (2011): S44.
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Crowding influences the dynamics of molecules themselves. In this study, we consider the influences of molecular crowding on the signaling using a lattice gas model, which simplifies G-protein-mediated signaling cascade on cell membrane and realizes the excluded volume effect of molecules. In the model, three types of proteins: Receptor, Signaling protein (hereafter S-protein), and Target protein (hereafter Target) are taken into account, and each protein walks randomly on the two dimensional hexagonal lattice which represents the cell membrane. Proteins are assumed to transmit the signal with the process; Receptor → S-protein → Target, by the direct contact at the adjacent sites. By the simulation, we obtain the relation among the density of Receptor, the density of S-protein, the joint probability of Target to the membrane, and activation frequency with which S-proteins activate Target, and find that i) the maximum activation frequency is realized when most sites is occupied by the proteins, and ii) proteins locally form characteristic spatial structure centering around Target. These results indicate that molecular crowding assists the effective transmit of signal in living cells.