The CB1 cannabinoid receptor is a target for pharmaceutical drug design for neuroprotection in stroke, muscle relaxation in spastic disorders, analgesia, metabolic energy balance, and substance abuse disorders. However, unwanted side effects, such as cognitive and memory dysfunction, emotional disorders, and sedation, have curtailed development of CB1 ligands for therapeutic purposes. CB1 receptors regulate signal transduction pathways that modulate neuronal functions intrinsic to neuroprotection, synaptic plasticity, and neurotransmitter release. The working hypothesis is that CB1 receptor agonist and antagonist ligands exert their influence on the juxtamembrane C-terminal domain to initiate key signal transduction pathways in neuronal cells;and that this signaling can be modulated by palmitoylation, phosphorylation, and protein association at the juxtamembrane C-terminal domain. The proposed research will elucidate mechanisms by which CB1 ligands trigger receptor-Gi/o protein activation of signal transduction via the effectors adenylyl cyclase and mitogen activated protein kinase (MAPK), leading to phosphorylation pathways regulated by protein kinase A (PKA) and ERK1/2.
The aims are to: 1. Characterize the signal transduction dependence on the juxtamembrane C-terminal domain. The cAMP/PKA and ERK responses to CB1 agonists having diverse structure and efficacy will be investigated in CB1 (L7.60(404)I,F) mutants stably expressed in HEK293 fibroblast and SH-SY5Y neuronal cells. 2. Characterize the effects of palmitoylation at the juxtamembrane C-terminal on CB1 receptor function by determining agonist-evoked responses in a C7.71(415)S CB1 mutant stably expressed in HEK293 and SH- SY5Y cells. 3. Characterize the effects of phosphorylation at the juxtamembrane C-terminal Ser/Thr on CB1 receptor function by determining agonist-evoked responses in phosphorylation-deficient (S401A, S410A, S414A) and phosphorylation-mimics (S401D, S410D, S414D) CB1 mutants stably expressed in SH-SY5Y cells. 4. Characterize the regulation of signal transduction via GASP1 interaction with the juxtamembrane C-terminal H8 domain of the CB1 receptor by examining the influence of juxtamembrane C-terminal disruption (L7.60(404)I,F), palmitoylation, and phosphorylation on CB1-GASP1a protein associations will be examined. The results of the proposed research will advance our understanding of biochemical mechanisms by which CB1 orthosteric ligands activate neuronal signaling responses. This understanding is critical to the design of drugs targeting the beneficial clinical responses with minimal undesirable effects.
The CB1 cannabinoid receptor is a target for pharmaceutical drug design for neuroprotection in stroke, muscle relaxation in spastic disorders, analgesia, metabolic energy balance, and substance abuse disorders. Unwanted side effects (cognitive and memory dysfunction, emotional disorders, and sedation) have curtailed development of CB1 ligands for therapeutic purposes. The proposed research will elucidate biochemical mechanisms by which ligands regulate CB1 receptors at a domain that is key for initiation of cellular signaling processes. This information is critical for the design of drugs that can stimulate the therapeutic responses but diminish the undesirable effects. Development of legitimate CB1 medicines can dispel myths associated with the notion of medical marihuana.
|Blume, Lawrence C; Patten, Theresa; Eldeeb, Khalil et al. (2017) Cannabinoid Receptor Interacting Protein 1a Competition with ?-Arrestin for CB1 Receptor Binding Sites. Mol Pharmacol 91:75-86|
|Blume, Lawrence C; Leone-Kabler, Sandra; Luessen, Deborah J et al. (2016) Cannabinoid receptor interacting protein suppresses agonist-driven CB1 receptor internalization and regulates receptor replenishment in an agonist-biased manner. J Neurochem 139:396-407|
|Eldeeb, Khalil; Leone-Kabler, Sandra; Howlett, Allyn C (2016) CB1 cannabinoid receptor-mediated increases in cyclic AMP accumulation are correlated with reduced Gi/o function. J Basic Clin Physiol Pharmacol 27:311-22|
|Luessen, Deborah J; Hinshaw, Tyler P; Sun, Haiguo et al. (2016) RGS2 modulates the activity and internalization of dopamine D2 receptors in neuroblastoma N2A cells. Neuropharmacology 110:297-307|
|Conner-Kerr, Teresa; Malpass, Gloria; Steele, Arhalia et al. (2015) Effects of 35 kHz, low-frequency ultrasound application in vitro on human fibroblast morphology and migration patterns. Ostomy Wound Manage 61:34-41|
|Blume, Lawrence C; Eldeeb, Khalil; Bass, Caroline E et al. (2015) Cannabinoid receptor interacting protein (CRIP1a) attenuates CB1R signaling in neuronal cells. Cell Signal 27:716-726|
|Sesay, John S; Gyapong, Reginald N K; Najafi, Leila T et al. (2015) G?i/o-dependent Ca(2+) mobilization and G?q-dependent PKC? regulation of Ca(2+)-sensing receptor-mediated responses in N18TG2 neuroblastoma cells. Neurochem Int 90:142-51|
|Smith, Tricia H; Blume, Lawrence C; Straiker, Alex et al. (2015) Cannabinoid receptor-interacting protein 1a modulates CB1 receptor signaling and regulation. Mol Pharmacol 87:747-65|
|Schaich, Chris L; Shaltout, Hossam A; Grabenauer, Megan et al. (2015) Alterations in the Medullary Endocannabinoid System Contribute to Age-related Impairment of Baroreflex Sensitivity. J Cardiovasc Pharmacol 65:473-9|
|Keegan, Bradley M T; Beveridge, Thomas J R; Pezor, Jeffrey J et al. (2015) Chronic baclofen desensitizes GABA(B)-mediated G-protein activation and stimulates phosphorylation of kinases in mesocorticolimbic rat brain. Neuropharmacology 95:492-502|
Showing the most recent 10 out of 95 publications