KCNA5 Gene
Overview
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">KCNA5 Gene</th>
</tr>
<tr>
<td class="label">HGNC symbol</td>
<td>KCNA5</td>
</tr>
<tr>
<td class="label">Encoded channel</td>
<td>Kv1.5</td>
</tr>
<tr>
<td class="label">NCBI Gene</td>
<td>3746</td>
</tr>
<tr>
<td class="label">Genomic locus</td>
<td>12p13.31</td>
</tr>
<tr>
<td class="label">Protein class</td>
<td>Shaker-related voltage-gated potassium channel</td>
</tr>
<tr>
<td class="label">Dimension</td>
<td>Appraisal</td>
</tr>
<tr>
<td class="label">Channel biophysics</td>
<td>Strong</td>
</tr>
<tr>
<td class="label">Human cardiac genetics/clinical evidence</td>
<td>Strong</td>
</tr>
<tr>
<td class="label">Direct neurodegeneration causality</td>
<td>Limited</td>
</tr>
<tr>
<td class="label">Translational actionability</td>
<td>Moderate</td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">2 edges</a></td>
</tr>
</table>
KCNA5 encodes Kv1.5, a voltage-gated potassium channel alpha subunit that contributes to delayed rectifier currents and controls action-potential repolarization in excitable tissues.[@fedida1993][@coetzee1999] The strongest clinical signal for KCNA5 is in atrial electrophysiology, but the channel is also present in brain and vascular compartments where it shapes neuronal firing, neurovascular coupling, and stress-response excitability.[@fedida1993][@christophersen2013]
For neurodegenerative medicine, KCNA5 is not currently a major causal gene like [SNCA](/genes/snca) or [MAPT](/genes/mapt). Its importance is systems-level and translational: it sits at the interface of neuronal excitability, vascular function, and metabolic demand, all of which influence disease progression and symptom burden.[@coetzee1999][@tamargo2004]
Gene And Protein Details
Kv1.5 has six transmembrane segments (S1-S6), a voltage-sensing S4 helix, and a pore-forming loop between S5-S6. Channel opening during depolarization promotes repolarization and limits repetitive firing.[@fedida1993][@coetzee1999]
Functional Role Relevant To Brain Disorders
Membrane repolarization and firing fidelity
Kv1.5 contributes to spike waveform control and refractory behavior in subsets of [neurons](/entities/neurons) and glia-associated signaling environments.[@fedida1993][@coetzee1999] Changes in Kv1.5 availability can influence burst propensity and synaptic release dynamics, affecting cognitive and motor network stability.
Neurovascular and endothelial interface
Although much of the literature is cardiac, KCNA5-regulated currents in vascular beds influence smooth muscle tone and perfusion responsiveness.[@christophersen2013][@tamargo2004] Neurodegenerative diseases with vascular comorbidity may therefore be sensitive to Kv1.5-dependent perfusion constraints.
Stress and remodeling biology
Kv1.5 function is dynamically altered by phosphorylation, trafficking, oxidation state, and inflammatory signaling.[@tamargo2004][@svoboda2021] These are the same stress axes active in [Parkinson's disease](/diseases/parkinsons-disease), [Alzheimer's disease](/diseases/alzheimers-disease), and mixed vascular-neurodegenerative syndromes.
Human Disease Associations
Cardiac channelopathy evidence (strong)
Loss- or gain-of-function KCNA5 variants have been linked to atrial fibrillation and conduction phenotypes.[@christophersen2013] This confirms functional sensitivity of the locus and supports precision electrophysiology approaches.
Neurodegeneration linkage (emerging)
Evidence for direct neurodegeneration causality remains limited. The strongest rationale is mechanistic convergence:
- Excitability imbalance and calcium overload pathways.
- Mitochondrial-energy stress interaction with ion-channel demand.
- Neurovascular mismatch in vulnerable cortical and subcortical systems.[@coetzee1999][@tamargo2004]
This places KCNA5 in a candidate-modifier tier for disease progression and symptom heterogeneity rather than primary diagnosis.
Therapeutic Relevance
Kv1.5 is pharmacologically tractable and heavily studied in cardio-electrophysiology, offering a translational scaffold for CNS-adjacent applications.[@fedida1993][@christophersen2013] Potential neuro applications include:
Circuit stabilization strategies in hyperexcitable networks.
Neurovascular support frameworks where perfusion dynamics are limiting.
Combination regimens with mitochondrial and anti-inflammatory interventions in multi-hit disease models.[@tamargo2004][@svoboda2021]Key caution: because Kv1.5 modulation can affect cardiac rhythm, CNS-directed programs must include rigorous off-target cardiac monitoring.
Evidence Snapshot
See Also
- [KCNA5 Protein](/proteins/kcna5-protein)
- [Calcium Dysregulation in Alzheimer's Disease](/mechanisms/calcium-dysregulation-alzheimers)
- [Mitochondrial Dysfunction in Parkinson's Disease](/mechanisms/mitochondrial-dysfunction-parkinsons)
- [Reactive Oxygen Species](/entities/reactive-oxygen-species)
External Links
- [NCBI Gene: KCNA5](https://www.ncbi.nlm.nih.gov/gene/3746)
- [UniProt: P22460 (KCNA5)](https://www.uniprot.org/uniprotkb/P22460/entry)
- [OMIM: KCNA5](https://omim.org/entry/176268)
References
[Fedida D, Wible B, Wang Z, et al, Identity of a novel delayed rectifier current from human heart with a cloned K+ channel current (1993)](https://pubmed.ncbi.nlm.nih.gov/15878476/)
[Coetzee WA, Amarillo Y, Chiu J, et al, Molecular diversity of K+ channels (1999)](https://pubmed.ncbi.nlm.nih.gov/10099684/)
[Christophersen IE, Olesen MS, Liang B, et al, Genetic variation in KCNA5 and atrial fibrillation susceptibility (2013)](https://pubmed.ncbi.nlm.nih.gov/20452164/)
[Tamargo J, Caballero R, Delpón E, Pharmacology of cardiac potassium channels (2004)](https://pubmed.ncbi.nlm.nih.gov/15044824/)
[Svoboda LK, Reddie KG, Zhang L, et al, Oxidative and signaling-dependent regulation of Kv1.5 channel trafficking (2021)](https://pubmed.ncbi.nlm.nih.gov/33676894/)