Cannabinoid Receptor Subtypes - Biochemistry - Lecture Slides, Slides of Biochemistry

Download Cannabinoid Receptor Subtypes - Biochemistry - Lecture Slides and more Slides Biochemistry in PDF only on Docsity! Efficacy in CB1 Cannabinoid Receptor Signal Transduction . Docsity.com Cannabinoid Receptor Subtypes • CB1 – Found in neuronal cells and brain; other non-innervated tissue? – Regulates neurotransmitter release • CB1(A) – Splice variant mRNA found in human brain, but not predicted in rodent gene (Sanofi Recherche) – Similar pharmacology and signal transduction as CB1 • CB2 – Found in immune tissue (B cells, macrophages, T cells) – Activity not fully characterized • CB?? or CB? – ? Antinociceptive effects of anandamide in CB1 (-/-) mice (Martin) – ? Vascular effects of anandamide not reproduced by other agonists (Kunos) Docsity.com Homology Model of the CB1 Receptor Biopolymers (Peptide Sciences), 2003, 71, 169-189 E2 loop as a part of binding site extracellular intracellular Docsity.com Cannabinoid Receptor Agonists • Classical Cannabinoid (ABC-tricyclic) • Nonclassical Cannabinoid (AC-bicyclic; ACD-tricyclic) – CP55940; CP55244 (Pfizer) • Aminoalkylindole – WIN55212-2 (Sterling Research Inst.) • Eicosanoid – Arachidonylethanolamide (anandamide) – 2-Arachidonoylglycerol • Aryl Pyrazole analogs – Organon analogs (Razdan and Martin) OH OH HO CP55940 A C 1 2 3 4 5 6 7 8 9 10 11 12 1"2" 3" 1' 2' 3' 4' 5' 6' 7' 8' 9' OH OH HO CP55244 A C 1 2 3 4 5 6 7 8 9 10 12 1513 14 1' 2' 3' 4' 5' 6' 7' 8' 9'17 D OH O THC B C A 1 2 3 45 7 8 9 1' 2' 3' 4' 5' 10 11 WIN55212-2 N O O N O 1 3 5 8 10 Anandamide N H O OH Docsity.com 2-Arachidonylglyceryl ether (noladin ether) Some Other EndoCannabinoids O-Arachidonoyl ethanol ester (Virodhamine) 2-Arachidonoylglycerol (2-AG) O OH OH O 2.5 >141 O OH OH Devane et al. (1992) Science 258: 1946 Mechoulam et al. (1995) Biochem. Pharmacol. 50: 83 Hanus et al. (2001) PNAS 98: 3662 Porter et al. (2002) J. Pharmacol. Exp. Ther. 301: 1020 CB1/CB2 Affiniy Ratio O OH O ??? Docsity.com Cannabinoid receptor agonists inhibit N-type Ca2+ currents in differentiated N18 neuroblastoma cells Mackie et al., Mol.Phm.44:498’93 Docsity.com - + Serum WIN55212 C6 Glioma Cells Methanan- damide CP55940 Cannabinoid Agonist-induced MAPK Phosphorylation Signal Transduction via Gi/o + - + - + - Pertussis Toxin N18TG2 Neuroblastoma Cells - - - + + + Pertussis Toxin - + Serum MA WIN CP MA WIN CP Docsity.com CP55940 and Methanandamide induce Nitric Oxide (NO) production in N18TG2 neuroblastoma cells Control CP55940 Methanandamide L-NNA + Methanandamide Docsity.com Peptide CB1401 Disrupts the Association Between CB1 Receptor and Gi3 but not Gi1 or Gi2 in Rat Brain Membrane Extracts Peptide 401: - + - + - + Gi1 Gi2 Gi3 Docsity.com Peptide CB1401 Disrupts the CB1 Receptor Association with Go but not Gi1/2 in Rat Brain Membrane Extracts Docsity.com Peptide CB1401 Disrupts the Association Between CB1 Receptor and Gi3 but not Gi1 or Gi2 in Rat Brain Membrane Extracts Peptide 401: - + - + - + Gi1 Gi2 Gi3 Docsity.com Conformational changes in the intracellular surface may direct interaction with selective G proteins Docsity.com 0 20 40 60 80 100 10 100 1000  i1 Log [WIN 55212-2] (nM) R e la ti v e D e n s it y G  i/ C B 1 R  i3  i2 0 20 40 60 80 100 10 100 1000  i2  i1  i3 Log [DALN] (nM) R e la ti v e D e n s it y G  i/ C B 1 R 0 20 40 60 80 100 10 100 1000  i3  i2  i1 Log [Methanandamide] (nM) R e la ti v e D e n s it y G  i/ C B 1 R Agonist Regulation of Gi/CB1R Association Docsity.com CB1 Receptor Signaling via G-proteins • The domains of the CB1 receptor selective for interaction with G-proteins • Agonists can affect CB1 receptor – G-protein association differentially • Speculation on conformational induction & G-protein activation Docsity.com WIN55212-2 and CP55244 Binding to CB1 Receptor F5.42(278) V3.32(196) E(258) K3.28(192) CP55244 WIN55212-2 H-bonding: Y5.39(275) T5.38(274) Docsity.com G-protein Activation Mechanism by Receptor Conformational Change By breaking H-bonding network By breaking hydrophobic interaction By breaking H-bonding network CP55244 WIN55212-2 Docsity.com Response Phosphorylation by GRK Arrestin association Internalization Conformational Induction of R-G Complex by A Docsity.com