J Vet Sci.  2002 Sep;3(3):185-191.

Functional Role of Serine Residues of Transmembrane Dopamin VII in Signal Transduction of CB2 Cannabinoid Receptor

• Rhee MH

Abstract

Using site-directed mutagenesis technique, I have replaced serine 285 and serine 292 with the alanine, and assessed the binding of agonist and signaling such as the inhibition of adenylyl cyclase activity.I have found that serine 292 has an important role in the signal transduction of cannabinoid agonists, HU-210 and CP55940, but not in that of aminoalkylindoles derivatives WIN55,212-2. All mutants express well in protein level determined by western blot using monoclonal antibody HA 11 as compared with the wild type receptor.Interestingly, binding affinity of S285A and S292A mutants with classical cannabinoid agonist HU-243 was somewhat decreased. In signaling assay, the inhibition of adenylyl cyclase by HU-210, CP55940 and WIN55, 212-2 is the same order in both wild type receptor and S285A mutant receptor. However, S292A have been shown that the inhibition curves of adenylyl cyclase activity moved to the right by HU-210 and CP55940, but those of adenylyl cyclase activity did not by aminoalkylindole WIN55,212-2, which is indicating that this residue is closely related to the binding site with HU-210 and CP55940. In addition, serine 292 might take more important role in CB2 receptor and G-protein signaling than serine 285.

Keyword

Cannabinoids; CB2; Serine; G protein; Adenylyl cyclase; Site-directed mutagenesis

MeSH Terms

Adenylate Cyclase/*metabolism
Animals
Binding, Competitive
Blotting, Western
COS Cells
Cannabinoids/metabolism
Cercopithecus aethiops
Cyclohexanols/metabolism
Excitatory Amino Acid Antagonists/metabolism
Mutagenesis, Site-Directed
Protein Conformation
Protein Structure, Tertiary
Receptors, Cannabinoid
Receptors, Drug/genetics/metabolism/*physiology
Serine/metabolism/*physiology
Signal Transduction/physiology
Tetrahydrocannabinol/*analogs&derivatives/metabolism
Transfection