Figure 2.

W170S mutation impaired Zn²⁺-mediated potentiation and enhanced Zn²⁺-mediated inhibition of GlyR currents activated by different agonists. A, Left, The homology model of the GlyR α1 subunit based on the GluCl viewed from the outer face. Inset, Plan view of the GlyR pentamer. The arrow indicates the viewing angle. Right, The expanded illustration of the amino acid residues that affect Zn²⁺ potentiation. B, Representative traces represent biphasic modulation of Zn²⁺ on homomeric α1^WT (top) or α1^W170S (bottom) GlyR currents activated by glycine (EC₁₀). C, Averaged Zn²⁺ concentration–response curves for the modulation of EC₁₀ responses to glycine-activated currents in homomeric (top; α1^WT, n = 7; α1^W170S, n = 10) and heteromeric α1^W170Sβ GlyRs (bottom; α1^WT, n = 7; α1^W170S, n = 10). D, Averaged Zn²⁺ concentration–response curves for the modulation of EC₁₀ responses to β-alanine-activated currents in homomeric (top; α1^WT, n = 5; α1^W170S, n = 5) and heteromeric α1^W170Sβ GlyRs (bottom; α1^WT, n = 6; α1^W170S, n = 5). E, Averaged Zn²⁺ concentration–response curves for the modulation of EC₁₀ responses to taurine-activated currents in homomeric (top; α1^WT, n = 5; α1^W170S, n = 8) and heteromeric α1^W170Sβ GlyRs (bottom; α1^WT, n = 7; α1^W170S, n = 5).