F508del- and A561E-CFTR exhibit a time-dependent loss of channel activity in intact cells studied
at 37°C. The magnitude of CFTR-mediated iodide efflux elicited by BHK-WT-CFTR,
BHK-F508del-CFTR and BHK-A561E-CFTR cells is shown for an 8 h period at 37°C. Prior to study,
BHK-WT-CFTR cells were grown at 37°C, whereas BHK-F508del-CFTR and BHK-A561E-CFTR cells were
grown at 27°C for 24 h. Values represent cumulative iodide efflux stimulated by forskolin (10
μM) and potentiated by genistein (50 μM) normalized to that measured at time t
= 0 h, when cells expressing low temperature-rescued mutants were returned to 37°C.
Data are means ± SEM (wild-type, n = 4–5; F508del-CFTR,
n = 4–6; A561E-CFTR, n = 4–9);
*P < 0.05 versus response of same cell line at t = 0 h.