Figure 1.

Reduced sensitivity to bTSH stimulation of CHO cells stably expressing the mTSHR cDNA with six mutations. These mutations were corrected to generate a true wild-type mTSHR. Stably transfected CHO cells expressing either the mutated mTSHR or wild-type TSHR were incubated with the indicated concentrations of TSH for 1 h before assay of intracellular cAMP levels (see Materials and Methods). Each point is the mean ± range of values determined in duplicate wells of cells. This experiment is representative of four separate experiments (Fig. 3 depicts another experiment).