Related Experiment Video
Updated: Jul 1, 2026

Biochemical Reconstitution of Steroid Receptor•Hsp90 Protein Complexes and Reactivation of Ligand Binding
Published on: September 21, 2011
The CYP2B2 5' flank contains a complex glucocorticoid response unit
Etienne Audet-Walsh1, Antoine Amaury Lachaud, Alan Anderson
1Centre de recherche en cancérologie de l'Université Laval, L'Hôtel-Dieu de Québec, CHUQ, Québec, Canada.
Dexamethasone induces CYP2B genes through a complex glucocorticoid response unit. Constitutive androstane receptor (CAR) acts as an accessory factor in this dexamethasone response, enhancing both basal and induced levels.
Area of Science:
- Pharmacology
- Molecular Biology
- Genetics
Background:
- CYP2B enzymes are crucial for drug metabolism and are induced by various compounds.
- Phenobarbital (PB) and dexamethasone are known inducers of CYP2B genes in rodents.
- Constitutive androstane receptor (CAR) is essential for PB-induced CYP2B expression.
Purpose of the Study:
- To identify novel regulatory elements involved in dexamethasone-induced CYP2B gene expression.
- To elucidate the role of CAR in the dexamethasone response of CYP2B genes in vivo.
Main Methods:
- Deletion analysis of the CYP2B2 5' flanking region in reporter constructs.
- In vivo studies in mice to assess the effect of CAR on CYP2B10 protein levels after dexamethasone treatment.
Main Results:
- Identification of new glucocorticoid response elements (GREs) or accessory factor sites within the CYP2B2 5' flank.
- Demonstration that CAR enhances both basal and dexamethasone-induced CYP2B10 protein levels in mice.
- Evidence supporting a complex glucocorticoid response unit mediating CYP2B2 gene induction.
Conclusions:
- Dexamethasone-mediated induction of CYP2B genes involves a complex interplay of multiple regulatory elements.
- CAR plays a significant accessory role in the dexamethasone response of CYP2B genes, impacting both basal and induced expression.
- A model of a complex glucocorticoid response unit is proposed to explain CYP2B gene regulation by dexamethasone.
More Related Videos
10:51Reverse Yeast Two-hybrid System to Identify Mammalian Nuclear Receptor Residues that Interact with Ligands and/or Antagonists
Published on: November 15, 2013
13:22A Chemical Screening Procedure for Glucocorticoid Signaling with a Zebrafish Larva Luciferase Reporter System
Published on: September 10, 2013
Related Concept Videos
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Target Cell Response to Hormones
Notably, the cellular response can be regulated by altering the number of receptors expressed in the cell. For example, prolonged exposure to elevated hormone levels results in a gradual decline or down-regulation in the number of receptors for that specific hormone on the cell surface. Conversely, in response to low hormone levels, cells may use up-regulation, producing an...
Cushing Syndrome II: Pathophysiology
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Transducer Mechanism: G Protein–Coupled Receptors
GPCRs are also called heptahelical, 7TM, or...
GPCRs Regulate Adenylyl Cylase Activity
Two...