Interaction of steroid hormone receptors with transcription factors involves chromatin remodelling.

摘要: The mechanism by which steroid hormones modulate promoter utilization is not clear. Evidence from transfection studies and cell-free assays points to an interaction of the hormone receptors with general transcription factors, as well sequence-specific factors. Moreover co-activators or intermediary have been identified could mediate some transcriptional effects hormone-receptor complex. However, in addition this proteins directly involved transcription, a participation chromatin structure gene regulation becoming increasingly evident. In case MMTV promoter, nucleosomal organization seems be responsible for repression prior hormonal stimulation. This effect due occlusion nucleosome positioned on sequences such way that essential factors cannot access their recognition sites. Following induction, remodelling takes place enables whole complement sequence specific assemble promoter. Since complete occupancy binding sites does take when present naked DNA, appears required proper synergism between following induction. According model, positioning sets stage constitutive induction