Most transcription factors, including nuclear receptors, are widely modeled as binding regulatory elements as monomers, homodimers, or heterodimers.  Recent findings in live cells show that the glucocorticoid receptor (GR) forms tetramers on enhancers, due to an allosteric alteration induced by DNA binding, and suggest that higher oligomerization states are important for the gene regulatory responses of GR. Using a variant (GRtetra) that mimics this allosteric transition, we performed genome-wide studies using a GR knock-out cell line with reintroduced wild-type GR or reintroduced GRtetra. GRtetra acts as a super receptor by binding to response elements not accessible to wild-type receptor, and both induces and represses more genes than GRwt. These results argue that DNA binding induces a structural transition to the tetrameric state, forming a transient higher order structure that drives both the activating and repressive actions of glucocorticoids. SOURCE: Ville Paakinaho (villepaakinaho@gmail.com) - Biomedicine University of Eastern Finland

Pluto Bioinformatics

GSE108634: Glucocorticoid Receptor Quaternary Structure Drives Chromatin Occupancy and Transcriptional Outcome