Transcriptional coregulators of the nuclear receptor superfamily: coactivators and corepressors

Nuclear receptors, many of which undergo a major conformational change upon binding specific ligand, belong to a superfamily of proteins that bind to specific DNA sequences and control gene transcription. They regulate the as sembly of a transcriptional preinitiation complex at the promoter of target genes and modulate their expression in response to ligand. In particular, nuclear receptors repress or stimulate transcription by recruiting corepres sor or co-activator proteins, in addition to directly contacting the basal transcription machinery. In this review, we discuss recent progress in stud ies of these transcriptional coregulators of nuclear receptors.