Related Experiment Video
Updated: Aug 19, 2026

A Phenotyping Regimen for Genetically Modified Mice Used to Study Genes Implicated in Human Diseases of Aging
Published on: July 14, 2016
On the control of the hCYP11B2 gene expressing cytochrome P450 aldosterone synthase
Jean-Guy LeHoux1, Andrée Lefebvre
1Department of Biochemistry, Faculty of Medicine, University of Sherbrooke, Sherbrooke, Quebec, Canada. jean-guy.lehoux@usherbrooke.ca
Abstract:
We have previously reported that the protein kinase C ligand 12-O-tetradecanoyphorbol-13-acetate (TPA) inhibited the angiotensin II (AII) stimulated CYP11B2 gene expression in the adrenocortical H295R cell line. Here we report that TPA increased the level of phospho-p44/42 MAPK but AII did not. The MEK1 inhibitor PD98059 was found to increase the level of aldosterone synthase mRNA and the activity of a human CYP11B2(-2023 bp)-promoter construct. The cotransfection of H295R with ERK 1 and the hCYP11B2 promoter resulted in the inhibition of the promoter activity. TPA but not AII increased the level of the transcription factor JunB in nuclear extracts and the increase was partially abolished by the MEK1 inhibitor PD98059. The cotransfection of H295R with JunB and the hCYP11B2 promoter abolished the AII stimulating effect. Taken together these results suggest that TPA inhibits the AII-dependent activation of CYP11B2 via the p44/42 MAPK signaling pathway leading to an increase of the level of nuclear JunB.
Related Concept Videos
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Allosteric Proteins-ATCase
Aspartate transcarbamoylase (ATCase) is a cytosolic enzyme that catalyzes the condensation of L-aspartate and carbamoyl phosphate to N-carbamoyl-L-aspartate. This reaction is the first step in pyrimidine biosynthesis. UTP and CTP, the end products of the pyrimidine synthesis pathway,...
Cell Specific Gene Expression
Pharmacogenetics of Drug Transporters: P-Glycoprotein and Solute Carrier Transporters
GPCRs Regulate Adenylyl Cylase Activity
Two...
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
