Table 1.
Summary of binding data and cAMP activity results for RXFP1/2 chimeric constructs
| Receptor construct | pIC50 |
n | pEC50 |
n | ||
|---|---|---|---|---|---|---|
| H2 relaxin | INSL3 | H2 relaxin | INSL3 | |||
| RXFP1 | 8.85 ± 0.05 | 5.55 ± 0.27 | 3 | 10.7 ± 0.04 | No activity | 3 |
| RXFP12TMD | ND | ND | 10.2 ± 0.08 | No activity | 3 | |
| RXFP12&β1 | 8.82 ± 0.34 | 6.44 ± 0.12 | 3 | 10.7 ± 0.17 | <6 | 3 |
| RXFP12&β1&TMD | 8.96 ± 0.13 | 6.53 ± 0.17 | 3 | 10.2 ± 0.03 | No activity | 3 |
| RXFP2&βN2 | 8.54 ± 0.29 | 6.26 ± 0.19 | 4 | 10.6 ± 0.14 | <6 | 3 |
| RXFP12&βN2&TMD | 8.31 ± 0.19 | 6.19 ± 0.09 | 4 | 9.59 ± 0.20a | No activity | 3 |
| RXFP12&β3 | 8.42 ± 0.25 | 6.57 ± 0.27 | 4 | 9.63 ± 0.05a | 7.52 ± 0.06 | 3 |
| RXFP12&β5 | 8.45 ± 0.30 | 7.09 ± 0.63b | 4 | 10.56 ± 0.12 | 6.72 ± 0.05 | 3 |
| Eu-INSL3 binding | ||||||
| RXFP12(N-LRR6) | 7.58 ± 0.79 | 9.14 ± 0.08 | 3 | 7.17 ± 0.07c | No activity | 3 |
| RXFP2 | 7.73 ± 0.06 | 9.14 ± 0.11 | 3 | 9.13 ± 0.06 | 10.2 ± 0.12 | 3 |
| ECD-12&β1 | ND | 8.94 ± 0.19 | ||||
| ECD-1 | ND | 8.19 ± 0.20d,e | ||||
ND, not determined
a
P < 0.01 vs. RXFP1;
b
, P < 0.05 vs. RXFP1;
c
, P < 0.001 vs. all;
d
, P < 0.01 vs. RXFP2;
e
, P < 0.01 vs. RXFP12&β1.