NT5E Gene

NT5E Gene

Introduction

NT5E (Ecto-5'-Nucleotidase), also known as CD73, is a glycosylphosphatidylinositol (GPI)-anchored cell surface enzyme that catalyzes the hydrolysis of extracellular nucleotides to adenosine. As the rate-limiting enzyme in adenosine production, CD73 plays pivotal roles in purinergic signaling, immune regulation, neuroprotection, and cellular energy balance. It is widely expressed on various cell types within the central nervous system (CNS), including [neurons](/cell-types/neurons), [astrocytes](/cell-types/astrocytes), [microglia](/cell-types/microglia), oligodendrocytes, and endothelial cells, where it modulates synaptic transmission, neuroinflammation, and [blood-brain barrier](/entities/blood-brain-barrier) (BBB) function.

--- [@atga]
title: NT5E Gene [@caspase]
description: Gene page for Ecto-5'-Nucleotidase (CD73) [@kir]

--- [@katp]

<div class="infobox infobox-gene"> [@adenosine]

| | | [@receptors]
|---|---| [@neuroinflammation]
| Gene Symbol | NT5E |
| Full Name | Ecto-5'-Nucleotidase |
| Chromosomal Location | 6q14.3 |
| NCBI Gene ID | [4904](https://www.ncbi.nlm.nih.gov/gene/4904) |
| OMIM | [602872](https://www.omim.org/entry/602872) |
| Ensembl ID | ENSG00000135318 |
| UniProt ID | [P21589](https://www.uniprot.org/uniprot/P21589) |

</div>

Overview

NT5E Gene

Introduction

NT5E (Ecto-5'-Nucleotidase), also known as CD73, is a glycosylphosphatidylinositol (GPI)-anchored cell surface enzyme that catalyzes the hydrolysis of extracellular nucleotides to adenosine. As the rate-limiting enzyme in adenosine production, CD73 plays pivotal roles in purinergic signaling, immune regulation, neuroprotection, and cellular energy balance. It is widely expressed on various cell types within the central nervous system (CNS), including [neurons](/cell-types/neurons), [astrocytes](/cell-types/astrocytes), [microglia](/cell-types/microglia), oligodendrocytes, and endothelial cells, where it modulates synaptic transmission, neuroinflammation, and [blood-brain barrier](/entities/blood-brain-barrier) (BBB) function.

--- [@atga]
title: NT5E Gene [@caspase]
description: Gene page for Ecto-5'-Nucleotidase (CD73) [@kir]

--- [@katp]

<div class="infobox infobox-gene"> [@adenosine]

| | | [@receptors]
|---|---| [@neuroinflammation]
| Gene Symbol | NT5E |
| Full Name | Ecto-5'-Nucleotidase |
| Chromosomal Location | 6q14.3 |
| NCBI Gene ID | [4904](https://www.ncbi.nlm.nih.gov/gene/4904) |
| OMIM | [602872](https://www.omim.org/entry/602872) |
| Ensembl ID | ENSG00000135318 |
| UniProt ID | [P21589](https://www.uniprot.org/uniprot/P21589) |

</div>

Overview

CD73 is a glycosylphosphatidylinositol (GPI)-anchored cell surface enzyme that hydrolyzes extracellular nucleotides to adenosine. It plays critical roles in adenosine production, purinergic signaling, immune regulation, and neuroprotection. CD73 is expressed on various cell types including [neurons](/entities/neurons), [astrocytes](/entities/astrocytes), [microglia](/entities/microglia), and endothelial cells, where it modulates synaptic transmission, neuroinflammation, and blood-brain barrier function.

Normal Function

Purinergic Signaling

NT5E/CD73 hydrolyzes extracellular AMP to adenosine, serving as the rate-limiting enzyme in adenosine production. This reaction regulates purinergic signaling through four adenosine receptor subtypes:

• A1 receptors: Widely distributed, inhibit adenylate cyclase
• A2A receptors: High density in striatum, promote adenylate cyclase
• A2B receptors: Low affinity, activated under high adenosine conditions
• A3 receptors: Distributed in various brain regions

Synaptic Transmission

In the CNS, CD73-derived adenosine modulates:

• Synaptic plasticity and [long-term potentiation](/mechanisms/long-term-potentiation) (LTP)
• Neurotransmitter release (glutamate, GABA, dopamine)
• Neuronal excitability and resting membrane potential
• Sleep-wake cycles and arousal

Neuroimmune Regulation

CD73 has immunomodulatory properties:

• Inhibits microglial activation and pro-inflammatory cytokine production
• Promotes regulatory T cell (Treg) function
• Modulates astrocyte reactivity
• Regulates blood-brain barrier permeability

Myelin Maintenance

Emerging evidence suggests CD73 participates in oligodendrocyte function and myelin maintenance, with implications for demyelinating diseases.

Protein Structure

CD73 is a homodimeric enzyme, with each subunit consisting of:

• N-terminal domain (~320 aa): Contains the catalytic site
• C-terminal domain (~280 aa): Stabilizes the dimer
• GPI anchor: Attaches protein to cell membrane

Disease Associations

Alzheimer's Disease

CD73 is implicated in [Alzheimer's disease](/diseases/alzheimers-disease) through multiple mechanisms:

• Reduced CD73 activity in AD brains contributes to adenosine deficiency
• [Amyloid-beta](/proteins/amyloid-beta) (Aβ) pathology affects CD73 expression on astrocytes and [microglia](/cell-types/microglia-neuroinflammation)
• Dysregulated adenosine signaling contributes to neuroinflammation and cognitive impairment
• Genetic variants in NT5E may modify AD risk

Parkinson's Disease

In [Parkinson's disease](/diseases/parkinsons-disease):

• CD73 modulates dopaminergic neuron survival through A2A receptor signaling
• A2A receptor antagonists (caffeine) are associated with reduced PD risk
• CD73 activity affects neuroinflammation in the substantia nigra
• Dysregulated purinergic signaling contributes to motor symptoms

Multiple Sclerosis

CD73 has complex roles in [multiple sclerosis](/diseases/multiple-sclerosis):

• Deficient CD73 on T cells correlates with MS disease activity
• CD73-generated adenosine promotes immune tolerance
• Potential therapeutic target for modulating CNS autoimmunity

Stroke and Ischemia

Following cerebral ischemia:

• CD73-derived adenosine provides neuroprotection through A1 and A2A receptors
• Exogenous CD73 administration reduces infarct size
• Adenosine signaling modulates post-ischemic inflammation

Cancer

NT5E is overexpressed in various cancers and promotes tumor progression through:

• Immunosuppressive adenosine production
• Angiogenesis
• Metastasis

Therapeutic Implications

A2A Receptor Antagonists

A2A receptor antagonists derived from caffeine have been investigated for:

• Parkinson's disease motor symptoms
• Cognitive enhancement in AD
• Neuroprotection in stroke

CD73 Inhibitors

CD73 inhibitors are being developed for:

• Cancer immunotherapy
• Autoimmune diseases

CD73 Agonists

CD73 agonists may have therapeutic potential for:

• Neuroprotection
• Anti-inflammatory applications
• Promoting remyelination

Research Directions

Current research focuses on:

• Developing brain-penetrant CD73 modulators
• Understanding cell-type specific functions of CD73
• Exploring NT5E genetic variants as disease modifiers
• Clinical trials of A2A antagonists in neurodegenerative diseases

See Also

• [Genes Index](/genes)
• [Proteins Index](/proteins)
• [Neuroinflammation Pathway](/mechanisms/neuroinflammation-pathway)
• [Purinergic Signaling Pathway](/mechanisms/purigenic-signaling-pathway)
• [Adenosine Signaling](/mechanisms/adenosine-signaling)
• [Microglia](/cell-types/microglia)
• [Astrocytes](/cell-types/astrocytes)
• [Alzheimer's Disease](/diseases/alzheimers-disease)
• [Parkinson's Disease](/diseases/parkinsons-disease)

Background

The study of Nt5E Gene has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.

Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.

External Links

• [NCBI Gene - NT5E](https://www.ncbi.nlm.nih.gov/gene/4904)
• [UniProt - NT5E](https://www.uniprot.org/uniprot/P21589)
• [GeneCards - NT5E](https://www.genecards.org/cgi-bin/carddisp.pl?gene=NT5E)
• [OMIM - NT5E](https://www.omim.org/entry/602872)

References

Pathway Diagram

The following diagram shows the key molecular relationships involving NT5E Gene discovered through SciDEX knowledge graph analysis: