FIGURE 6:

Loss of Dsc2 leads to enhanced tension forces on DM after calcium switch. (A) Schematic of the FRET-based molecular TS. The tension sensitive module (TS mod) consists of the mTFP/Venus FRET pair separated by an elastic linker. TS mod was inserted into the cytoplasmic domain of Dsg2, where it can sense forces transmitted between the transmembrane domain (TM) and Dsg-specific terminal domain (DTD). High and low FRET indices correspond to low and high tension, respectively. Under mechanical loading (red arrows), mTFP/Venus FRET pair is separated, and the FRET is reduced. EC: extracellular domain, F: force. (B) Representative color-coded images of three independent experiments, where cold and hot colors, respectively, indicate low and high levels of FRET index on Dsg2 TS mod. Monolayers expressing Dsg2 TS mod showed altered forces across DMs in SKCO-15 Dsc2 KD cells compared with the nonsilenced control (NS) during cell–cell junction recovery after calcium switch (CaSw) at two time points (0 and 180 min). (C) Histograms represent the average FRET index. Data are representative from three independent experiments. Statistical analysis was done with two-way ANOVA, followed by Tukey´s posttest. *p < 0.05; ****p < 0.0001. Scale bar is 20 μm.