Fig. 9.

VX-770 exhibited no ATP-independent potentiation of hCFTR or mCFTR. A and B: representative inside-out macropatch hCFTR currents recorded with a ramp protocol as in Fig. 2. hCFTR channels were fully activated with 1 mM MgATP + 127.6 U/ml PKA and then allowed to fully deactivate after removal of ATP and PKA. Currents were reactivated with exposure to 1 mM MgATP alone (A), but not 10 μM VX-770 alone (B). C and D: representative inside-out macropatch mCFTR currents as in A and B. mCFTR channels were activated with 1 mM MgATP + 127.6 U/ml PKA for 20 min then allowed to fully deactivate after removal of ATP and PKA. mCFTR currents were reactivated with exposure to 1 mM MgATP alone (C) but not 0.5 μM VX-770 alone (D).