TABLE 1.
Functional characterization of the constitutively activating TSHR mutations
| Location | Transfected construct | Ballesteros/Weinstein numbering | Cell surface expression: FACS (% TSHR wt) | cAMP accumulation |
|
|---|---|---|---|---|---|
| Basal (fold wt) | TSH stimulated (% TSHR) | ||||
| pcDNA3 | 0 | 0.3 ± 0.1 | ND | ||
| wt TSHR | 100 | 1 | 100 | ||
| TMH1 | V421I | 1.39 | 105.8 ± 8.1 | 2.1 ± 0.4 | 85.4 ± 3.1 |
| TMH2 | Y466A | 2.56 | 102.3 ± 8.0 | 2.8 ± 0.5 | 49.7 ± 7.7 |
| TMH3 | T501A | 3.32 | 142.2 ± 9.0 | 3.4 ± 0.6 | 128.7 ± 12.8 |
| TMH6 | L587V | 5.44 | 89.5 ± 11.0 | 1.7 ± 0.4 | 96.6 ± 2.4 |
| TMH6 | M637C | 6.48 | 96.1 ± 7.7 | 2.4 ± 0.6 | 112.5 ± 24.0 |
| M637W | 73.2 ± 6,0 | 4.8 ± 1.2 | 101.3 ± 13.1 | ||
| TMH6 | S641A | 6.52 | 74.4 ± 1.8 | 3.1 ± 0.2 | 96.8 ± 3.5 |
| TMH6 | Y643F | 6.54 | 117.1 ± 10.7 | 2.1 ± 0.3 | 88.9 ± 0.1 |
| TMH6 | L645V | 6.56 | 82.0 ± 7.2 | 2.1 ± 0.3 | 100.4 ± 11.8 |
| TMH7 | Y667A | 7.42 | 74.9 ± 3.3 | 1.7 ± 0.4 | 85.4 ± 6.9 |
HEK 293 cells were transfected with the wt TSHR or mutated TSHRs. TSHR cell surface expression level was quantified on a FACS flow cytometer. Receptor expression was determined by the mean fluorescence intensity by comparison to wt TSHR. Data are means ± se of 2 independent experiments, each carried out in duplicate. pcDNA3 vector was used as a control. ND, not determined.