Figure 1.

Na_v1.5 constructs and K⁺ depolarization assay schematic. (a) Chemical structure of ANAP (left) and Na_v1.5 domain structure (right) are shown. (b) Na_v1.5(ANAP) constructs used in imaging and electrophysiology experiments are shown. Star = ANAP. (c) A schematic of K⁺ depolarization in cells expressing GFP-K_ir4.1 and Na_v1.5(ANAP) is shown. Net flux of K⁺ is zero at both membrane potentials. 5 mM [K⁺]_ext and 150 [K⁺]_int set the equilibrium potential at ∼ −80 mV, at which Na_v channels are expected to be closed. An increase to 150 mM [K⁺]_ext sets the equilibrium potential at ∼0 mV, at which a large population of Na_v channels is expected to be inactivated. To see this figure in color, go online.