FIGURE 4.

Sumoylation is important for T3-dependent induction and repression of gene expression. GH3 cells were transfected with siRNA SUMO (1, 2, or 3) or siRNA control using Nucleofactor V, program T-28 (Lonza, Inc.) and plated onto 24-well plates. After 48 h, cells were tested for knockdown efficiency and then cotransfected with expression vectors (TRα or TRβ) and reporter construct rGH-TRE-Luc (A) or rTHSβ-TRE (B) using Effectene transfection reagent (Qiagen). T3 (50 nm) was added, and a reporter assay performed after 6 h. C, RT-PCR analysis of SUMO mRNA after siRNA SUMO knockdown and TR mRNA expression in transfected cells. *, T3 induction compared with basal (p < 0.05); **, basal compared with expression without transfected TR and T3 (p < 0.05). C, confirmation of specificity of siRNA is shown with mRNA detection by q-PCR for each SUMO condition and an absence of effect of siRNA on other SUMOs, TRs, or GAPDH.