FIGURE 2.
The phosphomimetic amino acid glutamate in position 700 simulates PKC-dependent inhibition of STREX and prevents PKG-dependent activation. Bars represent conductances from inside-out membrane patches expressing either the S700E (A) or the S700A (B) mutant STREX channel at +20 mV. (A) Note that control Gm of the mutant channel (Ctr) is ∼50% smaller than Gm of the wild type channel (Wt). 300 nm PKG failed to enhance Gm whereas the inhibitory effect of 300 nm PKA is preserved in this mutant. B, S700A mutant shows the same characteristics as the wild type STREX channel (compare with Fig. 1). Means ± S.E. are shown. Numbers within bars represent the number of membrane patches. The intracellular (bath) Ca2+ concentration was 1 μm. **, p < 0.01; ns, not significant.