Fig. 3

Direct suppressive effect of PKC on channel activity in inside-out patches. a Representative current trace showing that PKC-α suppressed channel activity in the presence of MgATP and PMA, with the subsequent addition of GF109203X restoring channel activity. The V _p was held at +50 mV. The bath solution used was a KCl solution containing 10⁻⁶ M Ca²⁺. In this trace, the calculated NP _o values were 0.83 for control, 0.81 for PMA alone, 0 for PMA + PKC-α, and 0.78 for PMA + PKC-α + GF109203X. The doses of MgATP, PMA, PKC-α, and GF109203X were 1 mM, 500 nM, 1 U/ml, and 500 nM, respectively. b Summary of the effects of PMA (n = 8), PKC-α in the presence of PMA (n = 8), and GF109203X added after PMA and PKC (n = 6). **P < 0.01, significantly different compared with the control level, which was maintained by MgATP alone