Table 2. Comparison of the functional effects of S6 mutations.

Channel	BTXresistant?	Activation shift? ΔV1/2 act(mV)	Inactivation shift? ΔV1/2 inact(mV)	Decrease in current density? (fold change)
Pum NaV1.4 N432T (DI)	No	No	No	No
Pum NaV1.4 N830T (DII)	No	No	Yes; −10.8 ± 1.6	Yes; 14.8
Pum NaV1.4 N1306T (DIII)	No	No	No	No
Pum NaV1.4 N1609T (DIV)	Yes	Yes; +20.5 ± 1.5	Yes; −10.3 ± 2.1	Yes; 4.9
Pum NaV1.4 N1609A (DIV)	No	Yes; +19.6 ± 1.6	Yes; −13.4 ± 1.6	Yes; 4.1
Hs NaV1.4 N1591T (DIV)	Yes	Yes; +16.9 ± 2.7	Yes; −9.8 ± 1.2	Yes; 2.2
Rn NaV1.4 N1584T (DIV)	Yes	Yes; +18.0 ± 0.6	Yes; −27.0 ± 0.4	Yes; 10.3
Pt NaV1.4 (N1600T) (DIV)	No	No	Yes; −7.7 ± 0.9	No*
Dt NaV1.4 (N1600T) (DIV)	No	No	Yes; −9.8 ± 1.9	No*

Data represent measurements in transfected HEK293 cells. *, substantial current density loss in Xenopus oocytes. ΔV_1/2 act = V_{1/2, act mutant} -V_{1/2, act WT}. ΔV_{1/2 inact =} V_{1/2, inact mutant} -V_{1/2, inact WT.}