甲状腺激素受体 (TR)为配体依赖性转录因子。未结合T3 的TR与辅阻遏因子等形成复合物 ,此复合物通过使局部的组蛋白去乙酰化而使局部染色质变得紧密 ,进而抑制靶基因的基础转录。结合了T3 的TR与辅阻遏因子解离 ,转录恢复到基础水平。随后辅激活因子与结合了T3 的TR形成复合物 ,此复合物通过使组蛋白乙酰化而使局部染色质变得松弛 ,进而激活靶基因的转录。辅激活因子复合物还能使RNA聚合酶稳定 ,从而促进转录 Thyroid hormone receptor (TR) is a ligand-dependent transcription factor. Tregs not associated with T3 form complexes with co-repressors and the like, which deactivate local histones by deacetylation of localized histones, thereby inhibiting basal transcription of target genes. TR, which binds to T3, dissociates from the cofactor and transcribes to the basal level. The coactivator then forms a complex with the T3-bound TR, which causes local chromatin relaxation by acetylation of histones, thereby activating the transcription of the target gene. Coactivator complexes also stabilize RNA polymerase and promote transcription