Figure 2.

Enhancement of ATP-dependent CFTR activity in excised inside-out patches. CFTR channels were activated with 10 μM forskolin plus 25 nM calyculin A in cell-attached patches before excision into an inside-out configuration. (A) Genistein alone fails to open phosphorylated CFTR. Channel activity in excised inside-out patches was only seen in the presence of ATP. (B) Genistein could enhance channel activity in the presence of ATP. The steady state mean current amplitudes were 0.88 pA with ATP alone and 1.62 pA with ATP plus genistein.