A Pit-1 binding site 3' to the transcription start site inhibits transcription elongation in vitro

The transcription factor Pit-1 can autoregulate its own expression by interacting with binding sites associated with the Pit-1 gene. One of these binding sites is located within the transcribed region of the gene and appears to be responsible for negatively regulating Pit-1 transcription. Using unique constructions in an in vitro transcription system, we show here that binding of Pit-1 to its recognition element can impede the progress of transcription elongation through the occupied site. We propose that this is a viable mechanism for Pit-1 autoregulation.