Direct interaction of the τ1 transactivation domain of the human glucocorticoid receptor with the basal transcriptional machinery

摘要: We have used a yeast (Saccharomyces cerevisiae) cell free transcription system to study protein-protein interactions involving theτ 1 transactivation domain of the human glucocorticoid receptor that are important for transcriptional transactivation by the receptor. Purifiedτ 1 specifically inhibited transcription from a basal promoter derived from the CYC1 gene and from the adenovirus 2 major late core promoter in a concentration-dependent manner. This inhibition or squelching was correlated with the transactivation activity ofτ 1. Recombinant yeast TATA-binding protein (yTFIID), although active in vitro, did not specifically reverse the inhibitory effect ofτ1. In addition, no specific interaction betweenτ 1 and yTFIID could be shown in vitro by affinity chromatography. Taken together, these results indicate that theτ 1 transactivation domain of the human glucocorticoid receptor interacts directly with the general transcriptional …