FIGURE 2.

Effects on the single channel slope conductance of the α1β heteromeric GlyR of charge reversal mutations in the loop 5 extracellular conductance determinant. Representative recordings of inward (A) and outward (C) currents recorded from HEK cells in cell-attached mode at different voltages (display f_c = 1 kHz). B and D are inward and outward current-voltage relationships for wild type and mutant receptors: α1β (Δ), α1^KEβ (●), α1β^KE (▿), α1^KEβ^KE (□). Note that inward currents are insensitive to charge reversal mutations in this position, even when all five subunits carry the mutation. On the contrary, the conductance of outward currents is markedly decreased by this mutation, but only when the mutation is carried either by the α1 or by both the α1 and the β subunits. Mutating the β subunit on its own does not affect outward slope conductance. Slope conductance values for each subunit combination are reported in Table 2.