Table 1.
RNA injected |
K1/2, μM
|
||||||||
---|---|---|---|---|---|---|---|---|---|
cAMP
|
cGMP
|
n (60 mV)
|
I−60mV/I60 mV
|
Desensitization | |||||
60 mV | −60 mV | 60 mV | −60 mV | cAMP | cGMP | cAMP | cGMP | ||
αwt mono | 83 ± 3 | 89 ± 3 | 2.77 ± 0.13 | 2.85 ± 0.11 | 2.33 ± 0.06 | 2.56 ± 0.07 | 0.79 ± 0.01 | 0.81 ± 0.02 | No |
n = 26 | n = 26 | n = 10 | n = 10 | n = 25 | n = 10 | n = 28 | n = 12 | ||
αm mono | 715 ± 51 | ND | ND | ND | 1.77 ± 0.14 | ND | ND | ND | No |
n = 5 | n = 3 | ||||||||
αwt + β mono | 10.5 ± 0.8 | 16.9 ± 1.0 | 5.2 ± 1.2 | 12.8 ± 1.6 | 1.5 ± 0.1 | 1.3 ± 0.1 | 0.51 ± 0.01 | 0.49 ± 0.02 | Yes |
n = 20 | n = 20 | n = 4 | n = 4 | n = 20 | n = 4 | n = 44 | n = 29 | ||
αm + β mono | 53 ± 3 | 82 ± 10 | 12 ± 1 | 21 ± 1 | 1.46 ± 0.05 | 1.36 ± 0.07 | 0.60 ± 0.02 | 0.54 ± 0.02 | Yes |
n = 5 | n = 5 | n = 2 | n = 2 | n = 5 | n = 5 | n = 4 | n = 2 | ||
αwtαwt | 65 ± 2 | 76 ± 5 | 2.3 ± 0.2 | 2.4 ± 0.2 | 2.06 ± 0.07 | 2.56 ± 0.08 | 0.78 ± 0.1 | 0.81 ± 0.01 | No |
n = 7 | n = 7 | n = 7 | n = 7 | n = 7 | n = 7 | n = 7 | n = 7 | ||
αwtαm | 257 ± 8 | 274 ± 8 | 8.9 ± 0.3 | 9.5 ± 0.4 | 2.30 ± 0.04 | 2.79 ± 0.04 | 0.77 ± 0.01 | 0.79 ± 0.01 | No |
n = 16 | n = 16 | n = 15 | n = 15 | n = 16 | n = 15 | n = 15 | n = 15 | ||
αwtαwt + ββ | 8.5 ± 0.4 | 18.5 ± 1.5 | 5.6 ± 0.3 | 9.9 ± 1.2 | 1.36 ± 0.05 | 1.19 ± 0.06 | 0.57 ± 0.01 | 0.52 ± 0.02 | Yes |
n = 14 | n = 14 | n = 11 | n = 10 | n = 14 | n = 14 | n = 13 | n = 9 | ||
αwtαm + ββ | 28.4 ± 3.7 | 47.6 ± 4.4 | 9.1 ± 1.1 | 9.3 ± 1.1 | 1.21 ± 0.07 | 1.61 ± 0.10 | 0.62 ± 0.02 | 0.57 ± 0.04 | Yes |
n = 14 | n = 14 | n = 10 | n = 9 | n = 14 | n = 10 | n = 14 | n = 9 | ||
αwtαwt + βαwt | 15.3 ± 1.7 | 21.4 ± 1.9 | 3.5 ± 0.5 | 4.4 ± 0.5 | 1.26 ± 0.11 | 1.16 ± 0.06 | 0.55 ± 0.02 | 0.60 ± 0.02 | Yes |
n = 7 | n = 5 | n = 5 | n = 4 | n = 7 | n = 5 | n = 5 | n = 4 | ||
αwtαwt + βαm | 11.8 ± 1.3 | 19.6 ± 2.2 | 4.6 ± 0.5 | 8.1 ± 1.1 | 1.41 ± 0.07 | 1.50 ± 0.08 | 0.54 ± 0.02 | 0.54 ± 0.03 | Yes |
n = 10 | n = 7 | n = 4 | n = 5 | n = 8 | n = 4 | n = 7 | n = 4 | ||
αwtαm + βαm | 33.6 ± 5.2 | 46.9 ± 3.6 | 7.4 ± 0.3 | 8.4 ± 0.6 | 1.25 ± 0.04 | 1.18 ± 0.04 | 0.64 ± 0.01 | 0.62 ± 0.02 | Yes |
n = 10 | n = 10 | n = 9 | n = 9 | n = 10 | n = 10 | n = 10 | n = 9 |
The first six paramaters are from fits of the data to Hill equations of the form in Fig. 1. The current ratios are ratios of the Imax from the Hill equations fits, and are thus saturating currents elicited by cAMP or cGMP. Desensitization was measured by observing any current decline during successive brief depolarizations to 60 mV, applied 1/sec. Injections of αwtβ, βαwt, βαm, ββ, and coinjections of αwtβ and βαwt, and αwtβ and βαm dimers failed to elicit CNG currents, with a minimum of 10 oocytes tested for each. ND, not done.