RIP140 and MED1 compete for association with TRα. A, In vitro competition assay of RIP140 and MED1 with regards to binding to TRα. In vitro pull down assay between GST-TRα and 35S-RIP140 WT, with titration of unlabeled MED1 in vitro transcribed and translated (TNT) protein (upper). In vitro pull down assay between GST-TRα and 35S-MED1, with titration of unlabeled RIP140 WT TNT protein (lower). B, In vitro pull down assay between GST-TRα and 35S-RIP140 CN, with titration of unlabeled MED1 TNT protein (upper). In vitro pull down assay between GST-TRα and 35S-RIP140 CP, with titration of unlabeled MED1 TNT protein (lower).