Browse
Submit Data
Databases
API
Help

Dataset Information

19 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

A common molecular basis for exogenous and endogenous cannabinoid potentiation of glycine receptors.

ABSTRACT: Both exogenous and endogenous cannabinoids can allosterically modulate glycine receptors (GlyRs). However, little is known about the molecular basis of cannabinoid-GlyR interactions. Here we report that sustained incubation with the endocannabinoid anandamide (AEA) substantially increased the amplitude of glycine-activated current in both rat cultured spinal neurons and in HEK-293 cells expressing human α1, rat α2 and α3 GlyRs. While the α1 and α3 subunits were highly sensitive to AEA-induced potentiation, the α2 subunit was relatively insensitive to AEA. Switching a serine at 296 and 307 in the TM3 (transmembrane domain 3) of the α1 and α3 subunits with an alanine (A) at the equivalent position in the α2 subunit converted the α1/α3 AEA-sensitive receptors to sensitivity resembling that of α2. The S296 residue is also critical for exogenous cannabinoid-induced potentiation of I(Gly). The magnitude of AEA potentiation decreased with removal of either the hydroxyl or oxygen groups on AEA. While desoxy-AEA was significantly less efficacious in potentiating I(Gly), desoxy-AEA inhibited potentiation produced by both Δ(9)-tetrahydrocannabinol (THC), a major psychoactive component of marijuana, and AEA. Similarly, didesoxy-THC, a modified THC with removal of both hydroxyl/oxygen groups, did not affect I(Gly) when applied alone but inhibited the potentiation of I(Gly) induced by AEA and THC. These findings suggest that exogenous and endogenous cannabinoids potentiate GlyRs via a hydrogen bonding-like interaction. Such a specific interaction likely stems from a common molecular basis involving the S296 residue in the TM3 of the α1 and α3 subunits.

SUBMITTER: Xiong W

PROVIDER: S-EPMC3334839 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Structural basis for cannabinoid-induced potentiation of alpha1-glycine receptors in lipid nanodiscs.

Project description:Nociception and motor coordination are critically governed by glycine receptor (GlyR) function at inhibitory synapses. Consequentially, GlyRs are attractive targets in the management of chronic pain and in the treatment of several neurological disorders. High-resolution mechanistic details of GlyR function and its modulation are just emerging. While it has been known that cannabinoids such as Δ9-tetrahydrocannabinol (THC), the principal psychoactive constituent in marijuana, potentiate GlyR in the therapeutically relevant concentration range, the molecular mechanism underlying this effect is still not understood. Here, we present Cryo-EM structures of full-length GlyR reconstituted into lipid nanodisc in complex with THC under varying concentrations of glycine. The GlyR-THC complexes are captured in multiple conformational states that reveal the basis for THC-mediated potentiation, manifested as different extents of opening at the level of the channel pore. Taken together, these structural findings, combined with molecular dynamics simulations and functional analysis, provide insights into the potential THC binding site and the allosteric coupling to the channel pore.

| S-EPMC9388682 | biostudies-literature

Cannabinoid potentiation of glycine receptors contributes to cannabis-induced analgesia.

Project description:Cannabinoids enhance the function of glycine receptors (GlyRs). However, little is known about the mechanisms and behavioral implication of cannabinoid-GlyR interaction. Using mutagenesis and NMR analysis, we have identified a serine at 296 in the GlyR protein critical for the potentiation of I(Gly) by ?(9)-tetrahydrocannabinol (THC), a major psychoactive component of marijuana. The polarity of the amino acid residue at 296 and the hydroxyl groups of THC are critical for THC potentiation. Removal of the hydroxyl groups of THC results in a compound that does not affect I(Gly) when applied alone but selectively antagonizes cannabinoid-induced potentiating effect on I(Gly) and analgesic effect in a tail-flick test in mice. The cannabinoid-induced analgesia is absent in mice lacking ?3GlyRs but not in those lacking CB1 and CB2 receptors. These findings reveal a new mechanism underlying cannabinoid potentiation of GlyRs, which could contribute to some of the cannabis-induced analgesic and therapeutic effects.

| S-EPMC3388539 | biostudies-literature

Selective potentiation of alpha 1 glycine receptors by ginkgolic acid.

Project description:Glycine receptors (GlyRs) belong to the superfamily of pentameric cys-loop receptor-operated channels and are involved in numerous physiological functions, including movement, vision, and pain. In search for compounds performing subunit-specific modulation of GlyRs we studied action of ginkgolic acid, an abundant Ginkgo biloba product. Using patch-clamp recordings, we analyzed the effects of ginkgolic acid in concentrations from 30 nM to 25 ?M on ?1-?3 and ?1/?, ?2/? configurations of GlyR and on GABAARs expressed in cultured CHO-K1 cells and mouse neuroblastoma (N2a) cells. Ginkgolic acid caused an increase in the amplitude of currents mediated by homomeric ?1 and heteromeric ?1/? GlyRs and provoked a left-shift of the concentration-dependent curves for glycine. Even at high concentrations (10-25 ?M) ginkgolic acid was not able to augment ionic currents mediated by ?2, ?2/?, and ?3 GlyRs, or by GABAAR consisting of ?1/?2/?2 subunits. Mutation of three residues (T59A/A261G/A303S) in the ?2 GlyR subunit to the corresponding ones from the ?1 converted the action of ginkgolic acid to potentiation with a distinct decrease in EC50 for glycine, suggesting an important role for these residues in modulation by ginkgolic acid. Our results suggest that ginkgolic acid is a novel selective enhancer of ?1 GlyRs.

| S-EPMC4624854 | biostudies-literature

Identification of a stereotypic molecular arrangement of endogenous glycine receptors at spinal cord synapses.

Project description:Precise quantitative information about the molecular architecture of synapses is essential to understanding the functional specificity and downstream signaling processes at specific populations of synapses. Glycine receptors (GlyRs) are the primary fast inhibitory neurotransmitter receptors in the spinal cord and brainstem. These inhibitory glycinergic networks crucially regulate motor and sensory processes. Thus far, the nanoscale organization of GlyRs underlying the different network specificities has not been defined. Here, we have quantitatively characterized the molecular arrangement and ultra-structure of glycinergic synapses in spinal cord tissue using quantitative super-resolution correlative light and electron microscopy. We show that endogenous GlyRs exhibit equal receptor-scaffold occupancy and constant packing densities of about 2000 GlyRs µm-2 at synapses across the spinal cord and throughout adulthood, even though ventral horn synapses have twice the total copy numbers, larger postsynaptic domains, and more convoluted morphologies than dorsal horn synapses. We demonstrate that this stereotypic molecular arrangement is maintained at glycinergic synapses in the oscillator mouse model of the neuromotor disease hyperekplexia despite a decrease in synapse size, indicating that the molecular organization of GlyRs is preserved in this hypomorph. We thus conclude that the morphology and size of inhibitory postsynaptic specializations rather than differences in GlyR packing determine the postsynaptic strength of glycinergic neurotransmission in motor and sensory spinal cord networks.

| S-EPMC8752092 | biostudies-literature

Investigating the Effects of Exogenous and Endogenous 2-Arachidonoylglycerol on Retinal CB1 Cannabinoid Receptors and Reactive Microglia in Naive and Diseased Retina.

Project description:The endocannabinoid system (ECS) is a new target for the development of retinal disease therapeutics, whose pathophysiology involves neurodegeneration and neuroinflammation. The endocannabinoid 2-arachidonoylglycerol (2-AG) affects neurons and microglia by activating CB1/CB2 cannabinoid receptors (Rs). The aim of this study was to investigate the effects of 2-AG on the CB1R expression/downregulation and retinal neurons/reactive microglia, when administered repeatedly (4 d), in three different paradigms. These involved the 2-AG exogenous administration (a) intraperitoneally (i.p.) and (b) topically and (c) by enhancing the 2-AG endogenous levels via the inhibition (AM11920, i.p.) of its metabolic enzymes (MAGL/ABHD6). Sprague Dawley rats were treated as mentioned above in the presence or absence of CB1/CB2R antagonists and the excitatory amino acid, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA). Immunohistochemistry, Western blot and a 2-AG level analyses were performed. The 2-AG repeated treatment (i.p.) induced the CB1R downregulation, abolishing its neuroprotective actions. However, 2-AG attenuated the AMPA-induced activation of microglia via the CB2R, as concurred by the AM630 antagonist effect. Topically administered 2-AG was efficacious as a neuroprotectant/antiapoptotic and anti-inflammatory agent. AM11920 increased the 2-AG levels providing neuroprotection against excitotoxicity and reduced microglial activation without affecting the CB1R expression. Our findings show that 2-AG, in the three paradigms studied, displays differential pharmacological profiles in terms of the downregulation of the CB1R and neuroprotection. All treatments, however, attenuated the activation of microglia via the CB2R activation, supporting the anti-inflammatory role of 2-AG in the retina.

| S-EPMC10650178 | biostudies-literature

Supralinear potentiation of NR1/NR3A excitatory glycine receptors by Zn2+ and NR1 antagonist.

Project description:Coassembly of the glycine-binding NMDA receptor subunits NR1 and NR3A results in excitatory glycine receptors of low efficacy. Here, we report that micromolar concentrations of the divalent cation Zn(2+) produce a 10-fold potentiation of NR1/NR3A receptor responses, which resembles that seen upon antagonizing glycine binding to the NR1 subunit. Coapplication of both Zn(2+) and NR1 antagonist caused a supralinear potentiation, resulting in a >120-fold increase of glycine-activated currents. At concentrations >50 microM, Zn(2+) alone generated receptor currents with similar efficacy as glycine, implying that NR1/NR3A receptors can be activated by different agonists. Point mutations in the NR1 and NR3A glycine-binding sites revealed that both the potentiating and agonistic effects of Zn(2+) are mediated by the ligand-binding domain of the NR1 subunit. In conclusion, Zn(2+) acts as a potent positive modulator and agonist at the NR1 subunit of NR1/NR3A receptors. Our results suggest that this unconventional member of the NMDA receptor family may in vivo be gated by the combined action of glycine and Zn(2+) or a yet unknown second ligand.

| S-EPMC2527951 | biostudies-literature

Frequency-Dependent Cannabinoid Receptor-Independent Modulation of Glycine Receptors by Endocannabinoid 2-AG.

Project description:Endocannabinoids are known as retrograde messengers, being released from the postsynaptic neuron and acting on specific presynaptic G-protein-coupled cannabinoid (CB) receptors to decrease neurotransmitter release. Also, at physiologically relevant concentrations cannabinoids can directly modulate the function of voltage-gated and receptor-operated ion channels. Using patch-clamp recording we analyzed the consequences of the direct action of an endocannabinoid, 2-arachidonoylglycerol (2-AG), on the functional properties of glycine receptor channels (GlyRs) and ionic currents in glycinergic synapses. At physiologically relevant concentrations (0.1-1 μM), 2-AG directly affected the functions of recombinant homomeric α1H GlyR: it inhibited peak amplitude and dramatically enhanced desensitization. The action of 2-AG on GlyR-mediated currents developed rapidly, within ∼300 ms. Addition of 1 μM 2-AG strongly facilitated the depression of glycine-induced currents during repetitive (4-10 Hz) application of short (2 ms duration) pulses of glycine to outside-out patches. In brainstem slices from CB1 receptor knockout mice, 2-AG significantly decreased the extent of facilitation of synaptic currents in hypoglossal motoneurons during repetitive (10-20 Hz) stimulation. These observations suggest that endocannabinoids can modulate postsynaptic metaplasticity of glycinergic synaptic currents in a CB1 receptor-independent manner.

| S-EPMC3147161 | biostudies-literature

Blockade of ethanol-induced potentiation of glycine receptors by a peptide that interferes with Gbetagamma binding.

Project description:The large intracellular loop (IL) of the glycine receptor (GlyR) interacts with various signaling proteins and plays a fundamental role in trafficking and regulation of several receptor properties, including a direct interaction with Gbetagamma. In the present study, we found that mutation of basic residues in the N-terminal region of the IL reduced the binding of Gbetagamma to 21 +/- 10% of control. Two basic residues in the C-terminal region, on the other hand, contributed to a smaller extent to Gbetagamma binding. Using docking analysis, we found that both basic regions of the IL bind in nearby regions to the Gbetagamma dimer, within an area of high density of amino acids having an electronegative character. Thereafter, we generated a 17-amino acid peptide with the N-terminal sequence of the wild-type IL (RQH) that was able to inhibit the in vitro binding of Gbetagamma to GlyRs to 57 +/- 5% of control in glutathione S-transferase pull-down assays using purified proteins. More interestingly, when the peptide was intracellularly applied to human embryonic kidney 293 cells, it inhibited the Gbetagamma-mediated modulations of G protein-coupled inwardly rectifying potassium channel by baclofen (24 +/- 14% of control) and attenuated the GlyR potentiation by ethanol (51 +/- 10% versus 10 +/- 3%).

| S-EPMC2784719 | biostudies-literature

Glycine receptors

Project description: Not available

| S-EPMC2884578 | biostudies-literature

Positive selection in cathelicidin host defense peptides: adaptation to exogenous pathogens or endogenous receptors?

Project description:The cause of adaptive protein evolution includes internal (for example, co-evolution of ligand-receptor pairs) and external (for example, adaptation to different ecological niches) mechanisms. Host defense peptides (HDPs) are a class of vertebrate-specific cationic antimicrobial peptides evolving under positive selection. Besides their antibiotic activity, HDPs also exert an effect on multiple host immune cells, thus providing an ideal model to study selective agents driving their evolution. On the basis of a combination of computational and experimental approaches, we studied the evolution of LL-37-type HDPs in mammals, the mature peptide of cathelicidin CAP18 (herein termed CAP18-MP) and investigated the driving force behind the evolution. Using codon-substitution maximum likelihood models, we analyzed CAP18-MPs in 40 species belonging to nine mammalian Orders and identified four positively selected sites (PSSs) that all are located on two terminal unordered regions of CAP18-MPs. Grafting the two positively selected regions of human or whale CAP18-MP to the α-helical scaffold of a rabbit homolog (substituting its corresponding parts) led to no alterations in antibacterial activity, spectrum and action mode. Likewise, further deletion of the two terminal regions did not alter its functional features. Evolutionary conservation analysis of mammalian FPR2, a receptor known to interact with the C-terminal positively selected region of LL-37, revealed high evolutionary variability in its ligand-binding extracellular loop domains, matching sequence diversity of the unordered regions in CAP18-MPs. This is the first report describing that the signature of positive selection of cathelicidins is not associated with their direct bactericidal activity, but rather with the evolutionary variability of their endogenous receptors.

| S-EPMC5564380 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data