Fig. 6.

An increase in cytosolic Ca²⁺ causes dynamin-dependent internalisation of CFTR. a Cultures were pre-treated with dynasore (80 µM; black trace) for 30–60 min in media at 37 °C and then exposed to thapsigargin (TG; 200 nM) and the inhibitor, CFTR_inh-172 (172; 10 µM). Changes in current were measured using the fast whole-cell configuration of the patch clamp technique. Data are plotted as mean changes in conductance plotted relative to the maximum current reached at +100 mV when cells were perfused with forskolin (fsk; 5 µM). Grey trace indicates cells that had not been pre-treated with dynasore. b Changes in conductance under conditions indicated. Conductance was normalised to cell size. Data were analysed from the end of the exposure period to each agonist. Data are mean ± SEM (n = 7 cells). *p < 0.05 when compared to baseline. ^†p < 0.05 when compared to initial forskolin exposure. c Representative images showing the effect of vehicle, thapsigargin and dynasore + thapsigargin on CFTR or the effect of vehicle, thapsigargin and thapsigargin + forskolin. Changes in d intracellular and e membrane fluorescence after 30 min exposure to indicated Ca²⁺ agonist. Data are mean ± SEM (n = 199–323 cells from 6 coverslips). Scale bar represents 10 µm. *p < 0.05 compared to vehicle-treated cells ^†p < 0.05 compared to thapsigargin