Picture from Johnson, Christina K. et al. (2021) MicroPubl Biol

Figure 1. Plasmin enhances MEC-4(d) but not UNC-8(d) currents in a MEC-6-dependent manner: Estimation plots by unpaired t-Test analysis of currents recorded in oocytes not treated and treated with plasmin (Calin-Jageman and Cumming 2019). Individual data points, means and 95% confidence intervals are shown. In each graph, on the right, the black circle and the error bars indicate the difference between the means and its 95% confidence interval. A: Currents recorded at -100 mV from oocytes expressing MEC-4(d)+MEC-2+MEC-6 not treated (light red) and treated (dark red) with 10 μg/ml plasmin, as indicated. N = 15, each. The difference between the means was 4.68 (71% increase), the lower and upper 95% confidence levels were 2.45 and 6.83 respectively (38% and 104% change, respectively). B: Same as panel A for oocytes expressing UNC-8(d)+MEC-2+MEC-6 not treated (light blue) and treated (dark blue) with plasmin. N = 7 and 5. The difference between the means was 0.94 (6% increase), the lower and upper 95% confidence levels were -1.50 and 3.38 respectively (-10% and 22% change, respectively). C: Same as in A for oocytes expressing MEC-4(d)+MEC-2 not treated (light red) and treated (dark red) with plasmin. N = 15 and 13 respectively. The difference between the means was 0.003 (0% change), the lower and upper 95% confidence levels were -0.391 and 0.398 respectively (-41% and 41% change; such large percentage changes are due to the relatively large variability of small currents). D: Same as panel A for oocytes expressing UNC-8(d)+MEC-2 not treated (light blue) and treated (dark blue) with plasmin. N = 6 and 5. The difference between the means was -0.87 (6% decrease), the lower and upper 95% confidence levels were -3.92 and 2.17 respectively (-27% and 15% change, respectively). E: Alignment of the finger domain of MEC-4 and UNC-8 containing the predicted plasmin sites (yellow background). F: Schematic representation of a DEG/ENaC channel subunit based on its crystal structure (Jasti, Furukawa et al. 2007). Alpha helixes are shown as cylinders and beta sheets are represented as flat arrows. The finger domain (purple) contains the plasmin recognition site (yellow box). The shaded area around transmembrane domains 1 and 2 (TM1 and TM2) represents plasma membrane.