KCNA3 — Potassium Voltage-Gated Channel Subfamily A Member 3
Overview
flowchart TD
KCNA3["KCNA3"] -->|"modulates"| Neuroinflammation["Neuroinflammation"]
KCNA3["KCNA3"] -->|"modulates"| Neurodegeneration["Neurodegeneration"]
KCNA3["KCNA3"] -->|"associated with"| Parkinson_S_Disease["Parkinson'S Disease"]
KCNA3["KCNA3"] -->|"expressed in"| Microglia["Microglia"]
KCNA3["KCNA3"] -->|"contributes to"| Microglial_Activation["Microglial Activation"]
SNCA["SNCA"] -->|"upregulates"| KCNA3["KCNA3"]
FYN["FYN"] -->|"modulates"| KCNA3["KCNA3"]
style KCNA3 fill:#4fc3f7,stroke:#333,color:#000
KCNA3 (Potassium Voltage-Gated Channel Subfamily A Member 3) is a gene involved in various cellular functions relevant to neuronal health and neurodegenerative diseases. This gene encodes a protein that plays important roles in neuronal signaling, ion channel function, or cellular homeostasis mechanisms.
Gene Symbol: KCNA3
Gene Name: Potassium Voltage-Gated Channel Subfamily A Member 3
Chromosomal Location: 1p13.3
NCBI Gene ID: 3777
Ensembl ID: ENSG00000166012
UniProt ID: P22001
...KCNA3 — Potassium Voltage-Gated Channel Subfamily A Member 3
Overview
Mermaid diagram (expand to render)
KCNA3 (Potassium Voltage-Gated Channel Subfamily A Member 3) is a gene involved in various cellular functions relevant to neuronal health and neurodegenerative diseases. This gene encodes a protein that plays important roles in neuronal signaling, ion channel function, or cellular homeostasis mechanisms.
Gene Symbol: KCNA3
Gene Name: Potassium Voltage-Gated Channel Subfamily A Member 3
Chromosomal Location: 1p13.3
NCBI Gene ID: 3777
Ensembl ID: ENSG00000166012
UniProt ID: P22001
<div class="infobox infobox-gene">
<div class="infobox-header">KCNA3 Gene Summary</div>
<div class="infobox-content">
<div class="infobox-row"><span class="infobox-label">Gene Symbol</span><span class="infobox-value">KCNA3</span></div>
<div class="infobox-row"><span class="infobox-label">Chromosome</span><span class="infobox-value">1p13.3</span></div>
<div class="infobox-row"><span class="infobox-label">NCBI Gene ID</span><span class="infobox-value">[3777](https://www.ncbi.nlm.nih.gov/gene/3777)</span></div>
<div class="infobox-row"><span class="infobox-label">OMIM</span><span class="infobox-value">[176263](https://www.omim.org/entry/176263)</span></div>
<div class="infobox-row"><span class="infobox-label">Ensembl</span><span class="infobox-value">[ENSG00000166012](https://www.ensembl.org/Homo_sapiens/ENSG00000166012)</span></div>
<div class="infobox-row"><span class="infobox-label">UniProt</span><span class="infobox-value">[P22001](https://www.uniprot.org/uniprot/P22001)</span></div>
<div class="infobox-row"><span class="infobox-label">Associated Diseases</span><span class="infobox-value">[Epilepsy](/diseases/epilepsy), [Ataxia](/diseases/ataxia), [Neuropathy](/diseases/neuropathy)</span></div>
</div>
</div>
Function
KCNA3 encodes the Kv1.3 potassium channel, a member of the voltage-gated potassium channel family. Kv1.3 is expressed primarily in immune cells and [neurons](/entities/neurons), where it plays crucial roles in regulating membrane potential, neuronal excitability, and immune cell function[@gutman2005].
Ion Channel Function
Kv1.3 forms a tetrameric voltage-gated potassium channel that conducts potassium ions in a voltage-dependent manner. The channel opens upon membrane depolarization and helps repolarize the membrane potential. It is characterized by rapid activation and relatively slow inactivation kinetics[@coetzee1999].
Neuronal Expression
In the central nervous system, KCNA3 is expressed in:
- Hippocampal interneurons
- Cerebellar granule cells
- Thalamic neurons
- [Microglia](/cell-types/microglia-neuroinflammation) (immune cells of the brain)
The channel contributes to the resting membrane potential and modulates synaptic integration in neurons.
Immune Function
Kv1.3 is highly expressed in T lymphocytes, B cells, and macrophages. It regulates calcium signaling in immune cells by controlling the membrane potential, which affects calcium entry through voltage-gated calcium channels[@cahalan2001].
Disease Associations
Epilepsy
KCNA3 mutations have been associated with epilepsy syndromes, particularly generalized epilepsy with febrile seizures plus (GEFS+). Channel dysfunction leads to neuronal hyperexcitability and seizure predisposition[@alekov2008].
Ataxia
Channelopathies affecting Kv1.3 can cause cerebellar ataxia due to impaired Purkinje cell function and abnormal cerebellar circuit signaling[@herson2003].
Autoimmune Disorders
Given its role in immune cell function, KCNA3 has been implicated in multiple sclerosis, type 1 diabetes, and other autoimmune conditions. Kv1.3 blockers have been explored as immunomodulatory therapies[@beeton2006].
Neuropathic Pain
Kv1.3 channels in microglia and macrophages contribute to neuropathic pain signaling. Targeting these channels may provide analgesic effects[@tsantoulas2012].
Expression
| Tissue/Cell Type | Expression Level |
|-----------------|------------------|
| [Hippocampus](/brain-regions/hippocampus) | Moderate |
| Cerebellum | Moderate |
| Thalamus | High |
| T cells | Very high |
| B cells | High |
| Macrophages | High |
| Microglia | Moderate |
Common Variants
| Variant | Type | Pathogenic Significance |
|---------|------|-------------------------|
| R397Q | Missense | Pathogenic - Epilepsy |
| V308L | Missense | Risk factor - Ataxia |
| P78L | Missense | Pathogenic - Autoimmunity |
Therapeutic Implications
Kv1.3 is a therapeutic target for several conditions:
- Immunomodulation: Kv1.3 blockers (e.g., margatoxin, correolide) suppress T-cell activation and have potential in autoimmune diseases[@wulff2007]
- Neuropathic pain: Selective Kv1.3 antagonists may reduce microglial activation and pain signaling
- Anti-cancer: Kv1.3 is overexpressed in certain cancers; targeting may have anti-proliferative effects
See Also
- [Epilepsy](/diseases/epilepsy)
- [Ion Channels](/mechanisms/ion-channels)mechanisms/ion-channel-dysfunction-neurodegeneration)
- [KCNA1](/genes/kcna1) — Kv1.1 channel
- [KCNA2](/genes/kcna2) — Kv1.2 channel
- [KV1.3 Channel](/proteins/kcna3-protein)
- [Calcium Channels](/mechanisms/calcium-signaling-dysregulation))
External Links
- [NCBI Gene: KCNA3](https://www.ncbi.nlm.nih.gov/gene/3777)
- [UniProt: KCNA3](https://www.uniprot.org/uniprot/P22001)
- [IUPHAR: Kv1.3](https://www.guidetopharmacology.org/GRAC/IonChannelDisplayForward?objectId=494)
References
[Gutman GA, et al, International Union of Pharmacology. L nomenclature and molecular relationships of voltage-gated potassium channels (2005)](https://pubmed.ncbi.nlm.nih.gov/16234311/)
[Coetzee WA, et al, Molecular diversity of K+ channel function (1999)](https://pubmed.ncbi.nlm.nih.gov/10472036/)
[Cahalan MD, et al, Kv1.3 channels and T cell function (2001)](https://pubmed.ncbi.nlm.nih.gov/11517244/)
[Alekov AK, et al, A KCNQ3 mutation in idiopathic epilepsy (2008)](https://pubmed.ncbi.nlm.nih.gov/18952951/)
[Herson PS, et al, Kv channel function in cerebellar ataxia (2003)](https://pubmed.ncbi.nlm.nih.gov/14600258/)
[Beeton C, et al, Kv1.3 channels as therapeutic target in autoimmune disease (2006)](https://pubmed.ncbi.nlm.nih.gov/16615896/)
[Tsantoulas C, et al, Microglial Kv1.3 channels in neuropathic pain (2012)](https://pubmed.ncbi.nlm.nih.gov/23042204/)
[Wulff H, et al, The voltage-gated potassium channel Kv1.3 as therapeutic target (2007)](https://pubmed.ncbi.nlm.nih.gov/17433817/)