Figure 3.

Mutations of serine 343 in γ2L subunits allow for “rogue” surface expression and anomalous Zn²⁺ blockade, and external application of truncated extracellular γ2 subunits reduces Zn²⁺ block in αβ receptors. A. Confocal images of cells co-transfected with EGFP and γ2L-S343D (serine to aspartate) or γ2L-S343V (serine to valine) are shown on the left. Bar = 20 μm. B. In separate experiments, excised patches from cells transfected with α1β2γ2L-S343D or α1β2γ2L-S343V (both at the transfection ratio 1:1:0.1) were tested for DZ potentiation and Zn²⁺ blockade, as in Figure 1. Note that both mutations cause γ2L to resemble γ2S.