Fig. 5
TSHR internalization is associated with a late cAMP/PKA response at the Golgi/TGN. Primary thyroid cells isolated from Epac1-camps transgenic mice or from wild-type mice and transfected with various FRET-based sensors were used to monitor cAMP and PKA responses in real time. Cells were pretreated with or without (control) dynasore for 30 min, followed by TSH stimulation. Data were normalized to the basal value (set to 0) and the maximal response to forskolin at the end of each experiment (set to 1). Differences at individual time points were compared using the Holm-Šídák test for multiple comparisons (black dots, P values). a cAMP FRET responses (mean ± s.e.m.; n = 8/10) in primary thyroid cells isolated from Epac1-camps mice. b PKA FRET responses (mean ± s.e.m.; n = 11/7) in primary thyroid cells transfected with the ubiquitous AKAR2 sensor. Data were fitted with a three phase exponential model with delay (see Methods). c cAMP FRET responses (mean ± s.e.m.; n = 4/5) in primary thyroid cells transfected with the Epac1-camps sensor targeted to the plasma membrane (Epac1-CAAX). d PKA FRET responses (mean ± s.e.m.; n = 11/10) in primary thyroid cells transfected with the AKAR2 sensor targeted to the plasma membrane (AKAR2-CAAX). e cAMP FRET responses (mean ± s.e.m.; n = 8/4) in primary thyroid cells transfected with the Epac1-camps sensor targeted to the Golgi/TGN (Epac1-GRIP). f PKA FRET responses (mean ± s.e.m.; n = 5/4) in primary thyroid cells transfected with the AKAR2 sensor targeted to the Golgi/TGN (AKAR2-GRIP)
