Transcriptional repression by nuclear hormone receptors.

Repression by nuclear receptors plays important roles in acute promyelocytic leukemia and other diseases. Nuclear receptor corepressor (N-CoR) and SMRT (silencing mediator of retinoic acid and thyroid hormone receptor) are corepressor proteins whose modular structure facilitates receptor interaction as well as transduction of repression signals involving histone deacetylation, alterations in chromatin structure and direct interactions with the basal transcription machinery. Interactions between nuclear receptors and corepressor complexes have multiple determinants. This allows regulation, and potentially therapeutic manipulation, of receptor, corepressor, cell-type and target-gene specificity.