Fig. 4.

The cAMP-dependent signaling pathway is responsible for the increases in protein and mRNA levels of transport factors. (A) Western blot of lysates from FRTL-5 cells grown under basal conditions (−FSK/−TSH, control) or treated either with FSK (+FSK, 10 μM) or TSH (+TSH, 1 mlU/ml) for 24 h. NIS and GAPDH were used as controls for TSH induction and loading, respectively. (B) Densitometric quantification of proteins in A normalized to the levels of GAPDH. Values indicate the fold change relative to protein levels in untreated cells. Results are mean±s.e.m. of three independent experiments (^•P<0.05; ^••P<0.01; ^•••P<0.001). (C) The CREB3L1 consensus motif identified upstream of 36 genes selected as described in the Results (listed in Table 1) as determined by Pscan.