Download Supplementary Figure Legends

Supplementary Figure Legends
Supplementary Figure 1. Statistic data indicating the average integrated I6.0 after
spermine (0.25 mM) treatment in cultured cortical neurons from WT and ASIC
knockout mice. Results are normalized to the integrals of I6.0 in the absence of
spermine (n = 4-6, **, p < 0.01, compared with the ratio of 1, paired t-test). The
dashed line indicates control values without SPM (the ratio of 1).
Supplementary Figure 2. Current-voltage relationship (I–V curve) of I6.0 without
(cycle) or with 0.25 mM SPM (triangle). Both datasets were fitted by linear
regression showing reversal potentials at approximately +40 mV, as shown by the
bar graph in inset (n = 5, NS, no statistical significance, paired t-test).
Supplementary Figure 3. In CHO cell transfected with human ASIC1a, extracellular
but not intracellular spermine altered I6.0. (A) Extracellular SPM ([SPM]o) at 0.25 mM
enhanced I6.0 regardless the absence (filled cycle) or presence (open cycle) of 0.25
mM SPM in the pipette. Data are mean ± SE (n = 6 for each group). (B)
Representative current traces and summary data (mean ± SE, n = 7) demonstrating
that SPM (0.25 mM) enhanced I6.0 in outside-out macro patch (**, P < 0.01, unpaired
t-test).
Supplementary Figure 4. In CHO cell transfected with human ASIC1a, SPM (0.25
mM) induced a rightward shift of the pH dependence of steady-state desensitization
of I6.0. For each point, n = 6-8. The holding pH varied from 7.6 to 6.6.
Supplementary Figure 5. Mutational analysis of SPM binding sites. (A) Typical
recording showing steady-state desensitization of WT and mutant ASIC1a channels
at two conditioning pH values indicated. (B) Statistic data indicating the % steadystate desensitization at pH 7.2 for WT (dashed line) and mutant ASIC1a channels (n
1
= 4-5, ***, p < 0.001, compared with WT channels, unpaired t-test). (C) Mutations
at E242 abolished the enhancing effect of 0.25 mM spermine. Results are
normalized to the relative peak amplitude of I6.0 in the absence of spermine (dashed
line) (NS, no statistical significance, n = 3-6, paired t-test). (D) In comparison with
the WT channels (see Supplementary Figure 4), SPM (0.25 mM) induced a less
significant rightward shift of the pH dependence of steady-state desensitization
under more acidic conditions in ASIC1aE219A mutant (n = 4-5). The holding pH
varied from 8.0 to 6.5.
2