Fig. 3.

Effect of coexpressed hβ₁ on hSkM1–P14 or hH1–P14 Na⁺ channel chimeras.A, Representative current tracings illustrating failure of hβ₁ to modulate inactivation in chimera hSkM1–P14. The response of hSkM1 to hβ₁ in the same experiment is also shown. B, Representative current tracings illustrating accelerated time course of inactivation caused by coexpression of hβ₁ with chimera hH1–P14.C, Plot of fractional recovery versus interpulse interval duration for hSkM1 (filled circles), hSkM1 + hβ₁ (open circles), hSkM1–P14 (filled diamonds), and hSkM1–P14+hβ₁ (open diamonds).D, Plot of fractional recovery versus interpulse interval duration (Δt) for hH1 (filled triangles), hH1–P14 (filled squares), and hH1–P14 + hβ₁ (open squares). Recovery from inactivation in hH1+hβ₁ is not shown but is identical to hH1 alone. (Results are represented for at least four cells; error bars are smaller than some data symbols.) Peak current amplitudes inA and B are scaled to unity. Recovery data in C and D are normalized to the current amplitude recorded after a recovery interval of 10 sec.