FIG. 4.

T3-dependent recruitment of CDK8-Mediator to the DioI promoter in vivo coincides with active transcription. (A) Schematic representation of the human DioI promoter. TREs and the specific location of the PCR primers are indicated. (B) T3-dependent recruitment of CDK8-Mediator to the DioI promoter in T3-responsive cells. Chromatin was prepared from α-2 cells cultured with or without T3 (10⁻⁷ M) for 1 h and then immunoprecipitated using the specific antibodies indicated on the right. The immunoprecipitates were subjected to semiquantitative PCR using specific primers spanning the TREs in the promoter region (shown in panel A). (C and D) T3-dependent activation of DioI mRNA expression. Total RNA was extracted from α-2 cells cultured with or without T3 (10⁻⁷ M) for 1 h and then assayed by RT-PCR semiquantitatively (C) or in real time (D) using primers specific for DioI or for β-actin as a control.