Chromatin architecture and the regulation of nuclear receptor inducible transcription.

Epigenetic mechanisms alter the structure of local chromosome domains to dynamically regulate gene expression by signalling and propagating transcriptional states. Nuclear receptors, a stimulus-inducible class of transcription factors, interact with chromatin to regulate transcription. To promote transcription, nuclear receptors interact with genomic regulatory elements that are epigenetically marked by modified histone tails, DNA methylation status, histone variants, chromatin accessibility and long-range interactions. Advances in throughput have allowed the profiling of regulatory factor activity on a genome-wide scale, with recent evidence from genomic analyses highlighting novel aspects of DNA-binding factor actions on chromatin. In the present review, the current knowledge of the mechanisms regulating nuclear receptor occupancy at cis-regulatory elements is discussed, with particular emphasis on the glucocorticoid, oestrogen and androgen receptors. Epigenetic regulation of genomic elements direct cell-specific regulatory factor binding and contribute to human variation in factor occupancy. Through regulating nuclear receptor activity, the epigenome is a critical checkpoint in nuclear receptor induced gene expression in health and disease.