Bistable front dynamics in a contractile medium: Travelling wave fronts and cortical advection define stable zones of RhoA signaling at epithelial adherens junctions
Fig 7
Response of the GTP-RhoA zone at the zonula adherens to changes in actomyosin contractility.
Spinning disk time lapse imaging of confluent MCF-7 epithelial cell monolayers expressing the GTP-RhoA reporter GFP-AHPH in control cells (Control, see also S1 Movie); before and after Y-27632 addition (60 μM, time of addition = 3 min, +Y-27632, see also S2 Movie) and before and after Y-27632 washout (S3 Movie). In the last case cells were pre-treated with 60 μM Y-27632 for 1 hour. A-C. Snapshot of the apical region of cells showing the distribution of GTP-RhoA at 0 and 120 min of image acquisition (A), before and after 40 min of Y-27632 treatment (B) and before and 150 min after removal of Y-27632 (C). D. Kymograph analysis of the GTP-RhoA zone for the conditions in A-C. Panels correspond to the analysis of the cell-cell junction indicated in A-C and S1, S2 and S4 Movies. E and F. Quantitation of the temporal changes (normalized to time t = 0) of the width (E) and mean fluorescence intensity (F) of the GTP-RhoA zone at the epithelial zonula adherens. Plots are mean ± SEM from 9 junctions from 3 independent movies.