Figure 1.

Activation of the cell integrity pathway (CIP) in response to osmotic shock is defective in exomer mutants. (a) Cells from the wild-type control (WT) and the exomer mutant cfr1Δ were exposed to 0.6 M of KCl for the indicated times (minutes). CIP activation was analysed in purified Pmk1-HA:6His samples by western blot using anti-p42/44 (phosphorylated Pmk1) and anti-HA (total Pmk1) antibodies. (b) The same as in (a), but the exomer mutant was bch1Δ. (c) CIP activation in cells treated with 0.6 M of KNO₃. (d) The indicated strains were collected by filtration, transferred from YES to YES with 1.2 M of sorbitol, incubated for the indicated times, and analysed for CIP activation. (e) CIP activation in cells treated with 25 mM of C₂H₃KO₂. (f) Cells growing in YES with 0.8 M sorbitol were transferred to YES, incubated for the indicated times, and analysed for CIP activation. (g) CIP activation in cells treated with 0.1 M of CaCl₂. (h) CIP activation in cells treated with 1 µg/ml of caspofungin. (i) CIP activation in cells incubated at 40°C for the indicated times. All the analyses were performed a minimum of three times. A representative blot is shown. The bar graphs depicted below the blots represent the CIP activity, calculated as the ratio between the p42/44 (phosphorylated Pmk1) and HA (total Pmk1) signals. They show the mean and standard deviation. a.u., arbitrary units. The Šidák correction was used after ANOVA to determine the statistical significance of the differences. ns, non-significant; *p < 0.05; **p < 0.01; ****p < 0.0001.