Tuyển tập các báo cáo nghiên cứu khoa học quốc tế về bệnh thú y đề tài: Functional Role of Serine Residues of Transmembrane Dopamin VII in Signal Transduction of CB2 Cannabinoid Receptor | J. Vet. Sci. 2002 3 3 185-191 JOURNAL OF Veterinary Science Functional Role of Serine Residues of Transmembrane Dopamin VII in Signal Transduction of CB2 Cannabinoid Receptor Man-Hee Rhee Department of Cell Biology Physiology Washington University School of Medicine St. Louis MO 63110 USA Received June 7 2002 Accepted August 17 2002 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 amino-alkylindoles 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. Key Words Cannabinoids CB2 Serine G protein Adenylyl cyclase Site-directed mutagenesis Introduction Two subtypes of cannabinoid CB receptors have been cloned so far CB1 and CB2 Matsuda et al. 1990 Munro et al. 1993 . Both CB1 and CB2 are members of the seven transmembrane TM domain G protein-coupled receptor Corresponding author Man-Hee Rhee Dept. of Cell Biology Physiology Washington University School of Medicine St .
