[Nuclear receptor-mediated signaling pathway]

Nuclear receptors for steroid/thyroid hormones, vitamins A and D, and fat-soluble ligands form a gene superfamily of ligand-inducible transaction factors, which plays important roles in a wide spectrum of biological events by regulating the expression of a set of target genes. DNA-bound nuclear receptors control transcription in a ligand-binding dependent way in cooperation with a multiprotein complex containing RNA polymerase II and a series of auxillary factors, TFIIA, B, D, E, F and H. During the process of ligand-induced transactivation by nuclear receptors, nuclear cofactors interacting with AF-1 and AF-2 seem to be involved. Several transcriptional co-activators and co-repressors forming coactivator complexes have been recently identified, and their function is discussed.