Figure 3.
M-protein promoter is responsive to T3. A, The rat M-protein promoter driving the firefly luciferase (LUC) reporter construct was cotransfected into C2C12 cells with either TRα, TRβ, or empty expression vector (pCMX). Cells were treated with progressive doses of T3 (0.01, 0.1, 1, and 100 nM) or vehicle (V). *, P < .001 vs V. B, Mean ± SD of transcriptional activity of 3×TRE D1 (positive control), −2298 to +228 bp and −158 to +228 bp promoter, and proximal regions of M-protein gene and promoter less pGL3 plasmid (negative control) transfected in C2C12 cells treated (+T3) or nontreated (−T3) with 50 nM T3. Promoter activity was arbitrarily set as 1 in all nontreated groups, and T3 effect was expressed as fold change. *, P < .01; and **, P < .001 vs respective untreated group. n = 3.