Figure 2. A single G628C/S631C hERG1 subunit eliminates C-type inactivation.

A, representative current traces for WT₄, GCSC₁/WT₃ and GCSC₄ concatenated tetramers recorded during 4 s pulses to −20 mV and +20 mV. Oocytes were bathed in 98Na2K extracellular solution. B, normalized current (I_test-norm) measured at the end of each 4 s test pulse plotted as a function of V_t for the indicated concatenated tetramers (n = 4–6). WT₄ channel currents were normalized to I_test at −20 mV. GCSC₄ and heterotypic tetramers were normalized to I_test at 0 mV. C, I_test-norm–V_t relationships for GCSC₄ and heterotypic channels. Currents were normalized to I_test at +50 mV. All relationships were linear (continuous lines). Symbols refer to constructs as indicated in (B).