Spatial gradients are sensitive to cell constriction only when the septum provides a significant diffusion barrier.A) Schematic of a dividing cell with oppositely localized kinase and phosphatase. fais the ratio of the area of the pore at the constriction site to the cross-sectional area in the cylindrical portion of the cell. B) 3D mathematical modeling of the distribution of [R ∼ P] in a dividing cell with fA=0.3. B) [R ∼ P] line scan through the cell middle showing volume-weighted average density along cell length for varying constriction sizes. D) Schematic of 1D distribution of kinase and phosphatase activities that produce profiles mimicking those in (C) for fA < 0.1 μm, with background kinase and phosphatase localized at the middle of the cell and overlapping by L/10.
Tropini et al. BMC Biophysics 2012 5:17 doi:10.1186/2046-1682-5-17