Identification and characterization of DNA sequences that restrict genomic binding of the glucocorticoid receptor

The glucocorticoid receptor (GR), is a hormone-activated transcription factor which binds to GR binding sequences (GBS) encoded in the genome. Interestingly, of the many genomic sequences matching the GR consensus sequence only a small subset is actually bound. This indicates that the presence of a GBS alone is insufficient to specify where in the genome GR binds. We identified sequences that can locally prevent GR binding and mass-spec analysis was used to identify proteins that bind to these sequences.