The long-term goal of this research proposal is to identify the molecular basis underlying the functions of the CB2 cannabinoid receptor. To achieve this purpose, the following steps will be taken.
In Aim 1 and 2, the interactive mutagenesis, molecular modeling and new compound testing studies will be carried out. This combined approach has advanced our understanding, and should continue to reveal new insights on how cannabinoid ligands are recognized by their receptors, the origin of receptor subtype-selectivity, and how these receptors are activated/inactivated. Cannabinoid receptors share many of the conserved sequence motifs seen in other well-studied G protein-coupled receptors (GPCRs), such as rhodopsin and biogenic amine receptors. However, several helix-bending residues and motifs, and a key disulfide bridge present in many other GPCRs are missing in cannabinoid receptors.
In Aim 3, Ligand binding crevice exposure of two transmembrane domains of CB2 cannabinoid receptor will be mapped using substituted-cysteine accessibility method. This approach should elucidate structural and functional consequences of the sequence divergence in these trasmembrane domains of cannabinoid receptors.
In Aim 4, Disulfide bond formation of CB2 receptor will be determined directly by the state-of-art methodologies of mass spectrometry. Investigating the unique disulfide bond or absence of a disulfide bond should provide important helix folding information of CB2 receptor, and this will have important implications regarding ligand binding crevice and activation mechanisms of this receptor. Finally, in Aim 5, effort will be devoted to over-express and purify large amounts of functional CB2 receptor. This challenging task, if successfully completed, should have a significant impact by providing the badly needed pure receptor proteins for future high-resolution biophysical studies. Overall, This study should help us to understand in more molecular detail the structure and function of CB2 receptor. CB2 is primarily distributed in the immune system. It is very important for the immune-modulatory effects of marijuana. In the long run, this study should also help us to develop better cannabinoid mimetics for the treatment of immune system illnesses, such as inflammation and autoimmune diseases. The drugs that specifically targeted at CB2 should be devoid of psvchoactive side effects of marijuana.

Agency
National Institute of Health (NIH)
Institute
National Institute on Drug Abuse (NIDA)
Type
Research Project (R01)
Project #
5R01DA011551-07
Application #
6886758
Study Section
Molecular, Cellular and Developmental Neurosciences 2 (MDCN)
Program Officer
Hillery, Paul
Project Start
1998-09-30
Project End
2009-04-30
Budget Start
2005-05-01
Budget End
2006-04-30
Support Year
7
Fiscal Year
2005
Total Cost
$257,250
Indirect Cost
Name
University of Louisville
Department
Pharmacology
Type
Schools of Medicine
DUNS #
057588857
City
Louisville
State
KY
Country
United States
Zip Code
40292
Brown, Kevin J; Laun, Alyssa S; Song, Zhao-Hui (2017) Cannabidiol, a novel inverse agonist for GPR12. Biochem Biophys Res Commun 493:451-454
Laun, Alyssa S; Song, Zhao-Hui (2017) GPR3 and GPR6, novel molecular targets for cannabidiol. Biochem Biophys Res Commun 490:17-21
Kumar, Pritesh; Carrasquer, Carl A; Carter, Arren et al. (2014) A categorical structure-activity relationship analysis of GPR119 ligands. SAR QSAR Environ Res 25:891-903
Kumar, Pritesh; Song, Zhao-Hui (2014) CB2 cannabinoid receptor is a novel target for third-generation selective estrogen receptor modulators bazedoxifene and lasofoxifene. Biochem Biophys Res Commun 443:144-9
Mnpotra, Jagjeet S; Qiao, Zhuanhong; Cai, Jian et al. (2014) Structural basis of G protein-coupled receptor-Gi protein interaction: formation of the cannabinoid CB2 receptor-Gi protein complex. J Biol Chem 289:20259-72
Kumar, Pritesh; Kumar, Akhilesh; Song, Zhao-Hui (2014) Structure-activity relationships of fatty acid amide ligands in activating and desensitizing G protein-coupled receptor 119. Eur J Pharmacol 723:465-72
Kumar, Pritesh; Song, Zhao-Hui (2013) Identification of raloxifene as a novel CB2 inverse agonist. Biochem Biophys Res Commun 435:76-81
Qiao, Zhuanhong; Kumar, Akhilesh; Kumar, Pritesh et al. (2012) Involvement of a non-CB1/CB2 cannabinoid receptor in the aqueous humor outflow-enhancing effects of abnormal-cannabidiol. Exp Eye Res 100:59-64
Kumar, Akhilesh; Qiao, Zhuanhong; Kumar, Pritesh et al. (2012) Effects of palmitoylethanolamide on aqueous humor outflow. Invest Ophthalmol Vis Sci 53:4416-25
He, Fang; Kumar, Akhilesh; Song, Zhao-Hui (2012) Heat shock protein 90 is an essential molecular chaperone for CB2 cannabinoid receptor-mediated signaling in trabecular meshwork cells. Mol Vis 18:2839-46

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