TABLE 1.
WT | G4934A | G4934V | G4941A | G4941V | G4941I | |
---|---|---|---|---|---|---|
Immunoblots (% WT) | 100 | 64.3 ± 8.6 (10)a | 78.0 ± 7.7 (10) | 69.5 ± 12.8 (13)a | 34.4 ± 13.1 (10)a | 68.9 ± 14.9 (15)a |
Caffeine response (% WT) | 100 | 99.0 ± 5.9 (6) | 17.1 ± 6.8 (6)a | 86.9 ± 8.8 (10) | 69.4 ± 10.8 (9)a | 31.3 ± 16.3 (3)a |
Bmax of [3H]ryanodine binding (% WT) | 100 | 74.5 ± 11.4 (10)a | 14.5 ± 5.3 (10)a | 30.7 ± 6.1 (20)a | 51.1 ± 7.0 (12)a | 6.7 ± 4.0 (8)a |
Po (2 μm Ca2+) | 0.29 ± 0.04 (19) | 0.29 ± 0.06 (19) | 0.50 ± 0.13 (12) | 0.08 ± 0.03 (12)a | 0.53 ± 0.04 (13)a | 0.38 ± 0.11 (12) |
Po (0.1 μm Ca2+) | 0.01 ± 0.01 (19) | 0.01 ± 0.01 (7) | 0.52 ± 0.13 (12) | 0.01 ± 0.01 (4) | 0.01 ± 0.01 (5) | 0.22 ± 0.08 (11) |
γK+ (pS) | 801 ± 7 (17) | 676 ± 5 (25)a | 564 ± 63 (12) | 771 ± 7 (12) | 799 ± 3 (13) | 585 ± 98 (12) |
Ica (+10 mm trans Ca2+) (pA) | −2.5 ± 0.1 (12) | −1.6 ± 0.1 (7)a | 0.1 ± 0.1 (12) | 2.3 ± 0.1 (8) | −2.8 ± 0.1 (7) | 0.1 ± 0.1 (10) |
PCa/PK | 6.7 ± 0.2 (12) | 5.4 ± 0.3 (6)a | NDb | 6.6 ± 0.3 (8) | 6.9 ± 0.2 (6) | ND |
No. of events/min (2 μm Ca2+) | 23,821 ± 2001 (19) | 13,924 ± 1743 (19)a | ND | 3605 ± 800 (10)a | 6400 ± 818 (13)a | ND |
τo (ms) (2 μm Ca2+) | 0.68 ± 0.06 (19) | 0.92 ± 0.10 (19) | ND | 1.23 ± 0.21 (10)a | 4.98 ± 0.72 (13)a | ND |
τc (ms) (2 μm Ca2+) | 2.39 ± 0.37 (19) | 4.28 ± 0.81 (19)a | ND | 19.4 ± 3.4 (10)a | 3.94 ± 0.27 (13)a | ND |
a p < 0.05 compared with WT.
b ND, not determined.