Table 1.
Properties of WT and variant channels
ND, not determined. Numbers in parentheses indicate the number of independent determinations.
| Immunoblot intensity | Caffeine-induced Ca2+ release | Single-channel properties |
||||
|---|---|---|---|---|---|---|
| Po at 0.01 μm Ca2+ | Po at 2 μm Ca2+ | γK+ | PCa/PK | |||
| % WTa | % WTb | pS | ||||
| WT | 100 | 100 | 0.0003 ± 0.0001 (7) | 0.10 ± 0.03 (10) | 766 ± 11 (12)c | 6.6 ± 0.2 (8)c |
| E3893Q | 540 ± 218 (9) | 119.0 ± 7.2 (4) | 0.0019 ± 0.0008 (4) | 0.0015 ± 0.0003 (4) | 810 ± 22 (4) | ND |
| E3893V | 772 ± 265 (9) | 101.2 ± 11.2 (3) | 0.0009 ± 0.0007 (4) | 0.0007 ± 0.0005 (4)d | 809 ± 13 (4) | ND |
| E3967Q | 298 ± 76 (8) | 77.6 ± 9.9 (4) | 0.0005 ± 0.0003 (3) | 0.0017 ± 0.0011 (4) | 780 ± 10 (4) | ND |
| E3967V | 494 ± 212 (9) | 46.5 ± 5.9 (5)e | 0.0005 ± 0.0003 (4) | 0.0011 ± 0.0004 (4) | 746 ± 18 (4) | ND |
| E3893Q/E3967Q | 207 ± 70 (10) | 105.6 ± 11.0 (4) | 0.020 ± 0.008 (10) | 0.016 ± 0.006 (10) | 790 ± 7 (5) | 6.2 ± 0.3 (4) |
| E3893V/E3967V | 728 ± 372 (9) | 48.9 ± 11.2 (4) | 0.0004 ± 0.0002 (7) | 0.0004 ± 0.0001 (8)d,f | 774 ± 24 (3) | ND |
| T5001A | 103 ± 40 (5) | 73.5 ± 11.5 (8) | 0.0004 ± 0.0003 (3) | 0.009 ± 0.007 (9) | 788 ± 14 (4) | 6.1 ± 0.3 (4) |
a Intensities of RyR1 variant bands on immunoblots were normalized to RyR1-WT intensities.
b Numbers of variant cells responding to 8 mm caffeine were normalized to WT cells showing a caffeine response; for each determination, 30–50 cells were examined.
c From Xu et al. (30).
d p < 0.05 compared with WT by Kruskal–Wallis one-way ANOVA followed by Dunn's method.
e p < 0.05 compared with E3893Q by Kruskal–Wallis one-way ANOVA followed by Dunn's method.
f p < 0.05 compared with E3893Q/E3967Q by Kruskal–Wallis one-way ANOVA followed by Dunn's method.