Related Experiment Video
Updated: Jun 14, 2026

Reverse Yeast Two-hybrid System to Identify Mammalian Nuclear Receptor Residues that Interact with Ligands and/or Antagonists
Published on: November 15, 2013
Evolution of 11beta-hydroxysteroid dehydrogenase-type 1 and 11beta-hydroxysteroid dehydrogenase-type 3
1Department of Medicine, University of California, San Diego, La Jolla, CA 92093-0693, USA. mbaker@ucsd.edu
Abstract:
A key regulator of glucocorticoid action is 11beta-hydroxysteroid dehydrogenase-type 1 (11beta-HSD1), which catalyzes the conversion of cortisone to cortisol, the biologically active glucocorticoid. 11beta-HSD1 is a paralog of 11beta-HSD3, whose physiological function remains unclear. As reported here, 11beta-HSD3 has orthologs in sea urchin, amphioxus and Ciona, while 11beta-HSD1 first appears in sharks. Thus, 11beta-HSD3 arose before the evolution of glucocorticoid signaling, suggesting different ancestral function(s) for 11beta-HSD3. Four perplexing findings arise from this evolutionary analysis: (1) 11beta-HSD1 is not present in a ray-finned fish genome, (2) zebrafish and fathead minnow contain two isoforms of 11beta-HSD3; (3) neither rat nor mouse contain 11beta-HSD3 and (4) amphioxus contains 16 11beta-HSD3 paralogs.
Related Concept Videos
Exon Recombination
Exon shuffling follows “splice frame rules.” Each exon has three reading...
Pharmacogenetics of Drug Targets: β₂-Adrenergic Receptors, Apo E, Thymidylate Synthase
Pharmacogenetics of Phase I Enzymes: Cytochrome P450 Isozymes
Adrenergic Receptors: β Subtype
Isoprenaline > Adrenaline > Noradrenaline
Neurotransmitter binding to these receptors causes activation of adenylyl cyclase resulting in increased concentrations of cAMP and modulation of calcium ion channels within the cell. They are further classified into β1, β2, and β3 subtypes.
β1-adrenoceptors: β1-adrenoceptors have equal affinities for...
Intracellular Hormone Receptors
Transducer Mechanism: Nuclear Receptors
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes: