A model for gene regulation by TR. T3 functions by regulating gene transcription through T3 receptors (TRs). In the absence of T3, TR/RXR heterodimer binds to TREs in the target genes and recruits corepressor complexes such as the N-CoR-HDAC3 complex. This leads to the establishment of a repressed chromatin state with ordered nucleosomal arrays and abundant repression marks. When T3 is present, TR/RXR recruits coactivator complexes such as those containing SRC, p300, and PRMT1. This leads to the loss of nucleosomes and modifications of the histone tails, leading to gene activation. See  for details.