Diacylglycerol Lipase Beta (DAGLβ)

Diacylglycerol Lipase Beta (DAGLβ)

Overview

<table class="infobox infobox-protein">
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<th class="infobox-header" colspan="2">Diacylglycerol Lipase Beta (DAGLβ)</th>
</tr>
<tr>
<td class="label">Symbol</td>
<td><strong>DAGLB</strong></td>
</tr>
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<td class="label">Full Name</td>
<td>Diacylglycerol Lipase Beta (DAGLβ)</td>
</tr>
<tr>
<td class="label">Type</td>
<td>Protein</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/?query=DAGLB" target="_blank">Search UniProt</a></td>
</tr>
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<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
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</table>

Diacylglycerol lipase beta (DAGLβ) is a member of the serine hydrolase family of enzymes that catalyzes the hydrolysis of diacylglycerol (DAG) to produce 2-arachidonoylglycerol (2-AG), one of the most abundant endocannabinoid neurotransmitters in the brain [1][2]. While DAGLβ is primarily expressed in peripheral tissues including the liver, kidney, and immune cells, it is also expressed in glial cells and certain neuronal populations where it plays important roles in neuroinflammation, synaptic signaling, and has been implicated in neurodegenerative diseases [3][4]. [@diacylglycerol2011]

Diacylglycerol Lipase Beta (DAGLβ)

Overview

<table class="infobox infobox-protein">
<tr>
<th class="infobox-header" colspan="2">Diacylglycerol Lipase Beta (DAGLβ)</th>
</tr>
<tr>
<td class="label">Symbol</td>
<td><strong>DAGLB</strong></td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Diacylglycerol Lipase Beta (DAGLβ)</td>
</tr>
<tr>
<td class="label">Type</td>
<td>Protein</td>
</tr>
<tr>
<td class="label">UniProt</td>
<td><a href="https://www.uniprot.org/uniprot/?query=DAGLB" target="_blank">Search UniProt</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">1 edges</a></td>
</tr>
</table>

Diacylglycerol lipase beta (DAGLβ) is a member of the serine hydrolase family of enzymes that catalyzes the hydrolysis of diacylglycerol (DAG) to produce 2-arachidonoylglycerol (2-AG), one of the most abundant endocannabinoid neurotransmitters in the brain [1][2]. While DAGLβ is primarily expressed in peripheral tissues including the liver, kidney, and immune cells, it is also expressed in glial cells and certain neuronal populations where it plays important roles in neuroinflammation, synaptic signaling, and has been implicated in neurodegenerative diseases [3][4]. [@diacylglycerol2011]

The endocannabinoid system, including 2-AG signaling through CB1 and CB2 receptors, has emerged as an important modulator of neuroinflammation, a key pathological feature of Alzheimer's disease (AD), Parkinson's disease (PD), and other neurodegenerative conditions [5]. [@endocannabinoid2005]

Enzyme Function and Biochemistry

Catalytic Activity

DAGLβ catalyzes the following reaction: [@dagl2014]

Diacylglycerol (DAG) + H₂O → 2-Arachidonoylglycerol (2-AG) + fatty acid [@endocannabinoid2019]

This hydrolysis reaction: [@neuroinflammation2018]

• Selectivity: Prefers DAG species containing arachidonic acid at the sn-1 position
• Substrate specificity: Acts on various DAG species, with preference for 2-AG precursors
• Cellular location: Active in cytosol and associated with endoplasmic reticulum membranes [6]

Enzymatic Properties

• Molecular weight: ~100 kDa
• Optimal pH: Neutral to slightly basic (pH 7-8)
• Catalytic mechanism: Serine hydrolase with classic catalytic triad
• Inhibition: Targetable by covalent inhibitors like THL (tetrahydrolipstatin) [7]

Gene and Protein Structure

Gene Organization

The DAGLB gene is located on chromosome 7p13 in humans and encodes a protein of approximately 90-100 kDa. The gene contains multiple exons and produces alternatively spliced variants [8]. [@dagl2012]

Protein Domain Architecture

DAGLβ contains several structural features: [@thl2010]

• Signal peptide: Directs secretion/transmembrane localization
• Serine hydrolase catalytic domain: Contains the active site serine
• Lipase motifs: GXSXG consensus sequences typical of serine lipases
• Membrane-binding regions: Hydrophobic domains for ER association [9]

Normal Physiological Functions

Endocannabinoid Synthesis

DAGLβ is a major source of 2-AG: [@daglb2009]

• 2-AG production: Responsible for bulk 2-AG synthesis in peripheral tissues
• Activity-dependent release: 2-AG is released in response to neuronal activity
• Retrograde signaling: 2-AG acts as a retrograde messenger at synapses [10]

Immune Function

In immune cells, DAGLβ regulates: [@dagl2013]

• T cell activation: 2-AG modulates T cell receptor signaling
• Macrophage function: Affects cytokine production and phagocytosis
• Immune cell migration: 2-AG gradients guide immune cell chemotaxis [11]

Metabolic Regulation

DAGLβ participates in lipid metabolism: [@retrograde2008]

• DAG catabolism: Removes DAG species that could accumulate
• Lipid signaling: Produces bioactive 2-AG from membrane phospholipids
• Energy homeostasis: Links lipid metabolism to endocannabinoid signaling [12]

Role in Neurodegenerative Diseases

Alzheimer's Disease

DAGLβ and 2-AG signaling are altered in AD: [@dagl2015]

• Neuroinflammation: 2-AG has complex pro- and anti-inflammatory effects in the brain. CB2 receptor activation on [microglia](/cell-types/microglia-neuroinflammation) can reduce neuroinflammation [13].
• [Amyloid-beta](/proteins/amyloid-beta) effects: Aβ exposure alters DAGLβ expression in glial cells
• Synaptic dysfunction: 2-AG signaling modulates synaptic plasticity, which is impaired in AD [14]
• Therapeutic potential: Modulating DAGLβ/2-AG axis may reduce neuroinflammation [15]

Parkinson's Disease

• Dopaminergic signaling: 2-AG modulates dopamine release and receptor signaling
• Neuroinflammation: CB2 receptor activation reduces microglial activation in PD models [16]
• Motor control: Endocannabinoid signaling affects basal ganglia function
• Therapeutic targeting: DAGL inhibitors and CB2 agonists have shown promise [17]

Multiple Sclerosis

• Demyelination: DAGLβ activity affects oligodendrocyte function
• Neuroinflammation: 2-AG is elevated in MS lesions and may be compensatory
• Remyelination: CB2 receptor activation promotes oligodendrocyte precursor differentiation [18]

Neuroinflammation

DAGLβ in glial cells regulates neuroinflammation: [@endocannabinoid2016]

• Microglial activation: 2-AG/CB2 signaling modulates microglial phenotype
• Cytokine production: Affects production of pro- and anti-inflammatory cytokines
• Neurotoxicity: Chronic inflammation contributes to neurodegeneration [19]

Therapeutic Implications

DAGL Inhibitors

Pharmacological inhibition of DAGL has been explored: [@alzheimers2020]

• THL (tetrahydrolipstatin): Irreversible inhibitor of DAGL activity
• Selective DAGLβ inhibitors: Development of isoform-selective compounds
• Clinical challenges: Broad serine hydrolase inhibition can cause side effects [20]

CB2 Receptor Agonists

Targeting the downstream 2-AG receptor: [@endocannabinoids2017]

• Anti-inflammatory effects: CB2 activation reduces microglial activation
• Neuroprotection: CB2 agonists have shown benefits in neurodegeneration models
• Peripheral immunity: CB2 modulates peripheral immune cell infiltration [21]

Modulating 2-AG Levels

Direct targeting of 2-AG metabolism: [@targeting2021]

• MAGL inhibitors: Monoacylglycerol lipase (MAGL) inhibitors increase 2-AG by preventing its breakdown
• Combined approaches: DAGL activation plus MAGL inhibition
• Selective targeting: Avoiding CB1-mediated psychoactive effects [22]

Signaling Pathways

Endocannabinoid System

2-AG signals through multiple receptors: [@parkinsons2019]

• CB1 receptors: Predominant in CNS, modulate neurotransmitter release
• CB2 receptors: Primarily in immune cells, mediate anti-inflammatory effects
• TRPV1 channels: Some 2-AG effects are mediated through TRPV1 [23]

Downstream Signaling

2-AG binding triggers: [@endocannabinoids2018]

• G-protein signaling: Gi/o protein-coupled receptor signaling
• cAMP modulation: Reduces cAMP production
• MAPK activation: Can activate ERK, p38, and JNK pathways
• Calcium signaling: Modulates voltage-gated calcium channels [24]

Cross-Talk

DAGLβ/2-AG interacts with other systems: [@endocannabinoids2017a]

• Dopamine signaling: Bidirectional interaction in basal ganglia
• Glutamate signaling: Modulates NMDA and AMPA receptor function
• GABA signaling: Affects inhibitory neurotransmission [25]

Cellular Distribution

Brain Expression

• Neuronal expression: Lower levels in [neurons](/entities/neurons) compared to glia
• [Astrocytes](/entities/astrocytes): Primary source of 2-AG in brain parenchyma
• Microglia: Induced expression under inflammatory conditions
• Oligodendrocytes: Expression increases during differentiation [26]

Peripheral Distribution

• Liver: High expression in hepatocytes
• Kidney: Tubular epithelial cells
• Immune system: T cells, B cells, macrophages
• Adipose tissue: Regulates lipolysis [27]

See Also

• [DAGLB Gene](/genes/daglb)
• [Endocannabinoid Signaling](/mechanisms/endocannabinoid-signaling)
• [2-Arachidonoylglycerol](/compounds/2-arachidonoylglycerol)
• [CB2 Receptor](/proteins/cnr2-protein)
• [Neuroinflammation](/mechanisms/neuroinflammation)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)

External Links

• [PubMed](https://pubmed.ncbi.nlm.nih.gov/)
• [KEGG Pathways](https://www.genome.jp/kegg/pathway.html)

References