FIGURE 4.

Functional properties of hybrid α6*-nAChR. Concentration (abscissa; log μm)-response (ordinate − mean normalized current ± S.E.) curves are shown for responses as follows. A, to nicotine for oocytes expressing hα6mβ4hβ3^V9′S- (○) or mα6hβ4mβ3^V9′S- (●) nAChR; B, to ACh (○) or nicotine (■) for oocytes expressing mαhβ2hβ3^V9′S-nAChR; C, to nicotine for oocytes expressing nAChR mα6 and hβ4 subunits with either hβ3 (■) or hβ3^V9′S (○) subunits; or D, to nicotine for oocytes expressing nAChR hα6, mβ4, and mβ3^V9′S subunits. A leftward shift in the nicotine concentration-response curve is evident for functional nAChR containing hβ3^V9′S subunits relative to nAChR containing wild-type hβ3 subunits (p < 0.0001; ∼173-fold). See Table 2 for parameters.