5va0
Glucocorticoid Receptor DNA Binding Domain in complex with AP-1 response element from VCAM-1 Promoter
Structural highlights
DiseaseGCR_HUMAN Defects in NR3C1 are a cause of glucocorticoid resistance (GCRES) [MIM:138040; also known as cortisol resistance. It is a hypertensive, hyperandrogenic disorder characterized by increased serum cortisol concentrations. Inheritance is autosomal dominant.[1] [2] [3] [4] [5] FunctionGCR_HUMAN Receptor for glucocorticoids (GC). Has a dual mode of action: as a transcription factor that binds to glucocorticoid response elements (GRE), both for nuclear and mitochondrial DNA, and as a modulator of other transcription factors. Affects inflammatory responses, cellular proliferation and differentiation in target tissues. Could act as a coactivator for STAT5-dependent transcription upon growth hormone (GH) stimulation and could reveal an essential role of hepatic GR in the control of body growth. Involved in chromatin remodeling. Plays a significant role in transactivation.[6] Publication Abstract from PubMedThe glucocorticoid receptor (GR) is a ligand-regulated transcription factor that controls the expression of extensive gene networks, driving both up- and down-regulation. GR utilizes multiple DNA-binding-dependent and -independent mechanisms to achieve context-specific transcriptional outcomes. The DNA-binding-independent mechanism involves tethering of GR to the pro-inflammatory transcription factor activator protein-1 (AP-1) through protein-protein interactions. This mechanism has served as the predominant model of GR-mediated transrepression of inflammatory genes. However, ChIP-seq data have consistently shown GR to occupy AP-1 response elements (TREs), even in the absence of AP-1. Therefore, the current model is insufficient to explain GR action at these sites. Here, we show that GR regulates a subset of inflammatory genes in a DNA-binding-dependent manner. Using structural biology and biochemical approaches, we show that GR binds directly to TREs via sequence-specific contacts to a GR-binding sequence (GBS) half-site found embedded within the TRE motif. Furthermore, we show that GR-mediated transrepression observed at TRE sites to be DNA-binding-dependent. This represents a paradigm shift in the field, showing that GR uses multiple mechanisms to suppress inflammatory gene expression. This work further expands our understanding of this complex multifaceted transcription factor. Tethering not required: the glucocorticoid receptor binds directly to activator protein-1 recognition motifs to repress inflammatory genes.,Weikum ER, de Vera IMS, Nwachukwu JC, Hudson WH, Nettles KW, Kojetin DJ, Ortlund EA Nucleic Acids Res. 2017 Jun 7. doi: 10.1093/nar/gkx509. PMID:28591827[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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