Figure 3.

M2-M3 linker mutations either enhance (β_m) or inhibit (α_m, γ_m) intrinsic pore opening in the absence of ligand. Spontaneous open probability for M2-M3 linker mutations α_m, β_m, or γ_m in the background of the gain-of-function mutation α1(L9′T) estimated as the ratio of PTX-sensitive to maximal GABA-evoked current amplitudes $I_{PTX}/I_{GABA·\mathit{max}}$ (see Fig. 2). Data points are for individual oocytes (α1(L9′T)β2γ2: n = 7; α_m(L9′T)β2γ2: n = 4; α1(L9′T)β_mγ2: n = 7; α1(L9′T)β2γ_m: n = 6). Boxplots indicate quartiles, and the vertical dashed line is the median for the α1(L9′T)β2γ2 background.