Fig. 2

Na_v1.7^R1488* is a non-functional ion channel. a Representative current traces in response to activating voltage steps (lower panel). No inward currents were observed in any cells expressing Na_v1.7^R1488* (left panel, 0/20 cells) whereas prominent inactivating currents were observed in cells expressing Na_v1.7^WT (right panel, 16/20 cells). b Current-voltage relationship for cells expressing Na_v1.7^R1488* show no detectable current for the mutant whereas cells expressing Na_v1.7^WT exhibited a clear current-voltage relationship typical for voltage-gated sodium channels (− 13.0 ± 0.8 mV, n = 10). c Quantitative PCR shows that both Na_v1.7^R1488* and Na_v1.7^WT cells express comparable amount of mRNA demonstrating that the variant is likely to be non-functional at the protein level. No mRNA is detectable in a parental cell line