KCNK1 Gene - Two-Pore Domain Potassium Channel
<table class="infobox infobox-gene">
<tr>
<th class="infobox-header" colspan="2">kcnk1</th>
</tr>
<tr>
<td class="label">Gene Symbol</td>
<td>KCNK1</td>
</tr>
<tr>
<td class="label">Full Name</td>
<td>Potassium Two Pore Domain Channel Subfamily K Member 1</td>
</tr>
<tr>
<td class="label">Aliases</td>
<td>TWIK-1, K2P1.1, TASK-1 (related family)</td>
</tr>
<tr>
<td class="label">Chromosomal Location</td>
<td>1q42.12</td>
</tr>
<tr>
<td class="label">NCBI Gene ID</td>
<td>3775</td>
</tr>
<tr>
<td class="label">OMIM</td>
<td>603457</td>
</tr>
<tr>
<td class="label">Ensembl ID</td>
<td>ENSG00000135750</td>
</tr>
<tr>
<td class="label">UniProt ID</td>
<td>O00180</td>
</tr>
<tr>
<td class="label">Gene Length</td>
<td>7.8 kb</td>
</tr>
<tr>
<td class="label">Exons</td>
<td>4</td>
</tr>
<tr>
<td class="label">Function</td>
<td>Mechanism</td>
</tr>
<tr>
<td class="label">Resting membrane potential</td>
<td>Background K+ leak conductance</td>
</tr>
<tr>
<td class="label">Neuronal excitability</td>
<td>Determines input resistance</td>
</tr>
<tr>
<td class="label">Cell volume regulation</td>
<td>Responds to osmotic stress</td>
</tr>
<tr>
<td class="label">Metabolic coupling</td>
<td>ATP-sensitive mechanisms</td>
</tr>
<tr>
<td class="label">Neuroprotection</td>
<td>Limits Na+ influx during stress</td>
</tr>
<tr>
<td class="label">Pathway</td>
<td>Interaction</td>
</tr>
<tr>
<td class="label">p38 MAPK</td>
<td>Phosphorylation</td>
</tr>
<tr>
<td class="label">PKC</td>
<td>Activation</td>
</tr>
<tr>
<td class="label">Calmodulin</td>
<td>Ca2+ binding</td>
</tr>
<tr>
<td class="label">ATP</td>
<td>Direct binding</td>
</tr>
<tr>
<td class="label">Approach</td>
<td>Status</td>
</tr>
<tr>
<td class="label">K2P activators</td>
<td>Preclinical</td>
</tr>
<tr>
<td class="label">K2P blockers</td>
<td>Clinical trials</td>
</tr>
<tr>
<td class="label">TASK-1 selective</td>
<td>Preclinical</td>
</tr>
<tr>
<td class="label">TWIK-1 modulators</td>
<td>Discovery</td>
</tr>
<tr>
<td class="label">Associated Diseases</td>
<td><a href="/wiki/als" style="color:#ef9a9a">ALS</a>, <a href="/wiki/als" style="color:#ef9a9a">Als</a>, <a href="/wiki/fibrosis" style="color:#ef9a9a">Fibrosis</a>, <a href="/wiki/heart-failure" style="color:#ef9a9a">Heart Failure</a>, <a href="/wiki/hypertension" style="color:#ef9a9a">Hypertension</a></td>
</tr>
<tr>
<td class="label">KG Connections</td>
<td><a href="/atlas" style="color:#4fc3f7">22 edges</a></td>
</tr>
</table>
Overview
KCNK1 (Potassium Two Pore Domain Channel Subfamily K Member 1) encodes the TWIK-1 potassium channel, a member of the two-pore domain (K2P) potassium channel family. These channels contribute to the background "leak" conductance that maintains the resting membrane potential and regulate neuronal excitability [1]. This page covers the gene structure, protein function, and its implications in neurodegenerative diseases including Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS).
Protein Structure and Function
Structure
K2P channels contain:
- Four transmembrane domains
- Two pore regions (P1 and P2) in tandem
- Extracellular loop between transmembrane helices
- Form functional dimers (homodimers or heterodimers)
The TWIK-1 channel has a characteristic selectivity filter with the sequence GFG [2].
Physiological Function
KCNK1/TWIK-1 contributes to background potassium conductance ("leak" currents") with several key functions:
Tissue Distribution
KCNK1 is widely expressed:
- Brain: High expression in cortex, hippocampus, cerebellum
- Heart: Cardiac myocytes
- Kidney: Tubular epithelial cells
- Lung: Alveolar cells
- Pancreas: Islet cells
In the brain, TWIK-1 is present in neurons and astrocytes, contributing to astrocytic K+ buffering [3].
Role in Neurodegenerative Diseases
Alzheimer's Disease
K2P channels, including TWIK-1, are affected in AD through multiple mechanisms:
Amyloid-beta effects: Aβ oligomers alter K2P channel expression and function [4].
Calcium dysregulation: K2P channels are calcium-sensitive and affected by AD-related calcium dysregulation.
Neuronal hyperexcitability: Reduced K2P function contributes to network hyperactivity in early AD [5].
Mitochondrial dysfunction: K2P channels affect mitochondrial K+ fluxes.Studies show altered K2P expression in AD hippocampus, contributing to seizure-like activity [6].
Parkinson's Disease
TWIK-1 alterations in PD include:
Dopaminergic neuron vulnerability: K2P dysfunction may increase excitotoxicity [7].
alpha-synuclein interaction: αSyn may affect K2P channel trafficking.
Mitochondrial stress: Altered K+ handling in PD models [8].
Glial contributions: Astrocytic K2P dysfunction affects extracellular K+ clearance.Amyotrophic Lateral Sclerosis
In ALS:
Motor neuron hyperexcitability: K2P dysfunction contributes to excessive firing [9].
Excitotoxicity: Altered K+ gradients affect glutamate transporter function.
Energy metabolism: K2P channels influence neuronal energy demands.Epilepsy (Comorbidity)
K2P channels are well-established in epilepsy:
Hyperexcitability: Loss of leak conductance leads to depolarized rest [10].
Mutation links: KCNK1 mutations associated with epilepsy phenotypes [11].
Therapeutic potential: K2P modulators under investigation for seizure control.Molecular Pathways
Signaling Interactions
TWIK-1 interacts with several signaling pathways:
Regulatory Mechanisms
- Phosphorylation: p38 MAPK and PKC modulate TWIK-1 activity [12].
- Trafficking: Channel insertion/removal from plasma membrane.
- Alternative splicing: Generates variants with different properties.
- Heterodimerization: Forms channels with other K2P subunits (TASK, TREK).
Therapeutic Implications
Drug Targets
K2P channels are emerging therapeutic targets:
Research Directions
Key areas for development:
Neuroprotective strategies: K2P activators for AD/PD.
Anti-epileptic drugs: Novel K2P-targeting compounds.
Analgesics: K2P3/TWIK-1 in pain pathways [13].
Antiarrhythmics: Cardiac K2P modulators.Key Publications
[Lesage F, et al. (1996). TWIK-1: a ubiquitous background potassium channel. J Biol Chem](https://pubmed.ncbi.nlm.nih.gov/8621702/)
[Goldstein SA, et al. (2001). K2P potassium channels: new functions. Trends Neurosci](https://pubmed.ncbi.nlm.nih.gov/11712047/)
[Reyes R, et al. (1998). TWIK-1, a ubiquitous background K+ channel. Pflugers Arch](https://pubmed.ncbi.nlm.nih.gov/9581669/)
[Talley EM, et al. (2001). Distribution of neuronal two-pore domain K+ channels. J Neurosci](https://pubmed.ncbi.nlm.nih.gov/11505184/)See Also
- [Potassium Channels in Neurodegeneration](/mechanisms/potassium-channels)
- [Two-Pore Domain Channels](/mechanisms/two-pore-domain-channels)
- [Neuronal Excitability in AD](/mechanisms/neuronal-hyperexcitability-ad)
- [Excitotoxicity Pathway](/mechanisms/excitotoxicity-pathway)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Parkinson's Disease](/diseases/parkinsons-disease)
External Links
- [NCBI Gene: KCNK1](https://www.ncbi.nlm.nih.gov/gene/3775)
- [UniProt: KCNK1](https://www.uniprot.org/uniprot/O00180)
- [IUPHAR Database: K2P channels](https://www.guidetopharmacology.org/)
References
[Shieh CC, Coghlan M, Sullivan JP, Gopalakrishnan M, Potassium channels: molecular defects, diseases, and therapeutic opportunities (2000)](https://pubmed.ncbi.nlm.nih.gov/10893102/)
[Wei AD, Gutman GA, Aldrich R, et al, International Union of Pharmacology (2005)](https://pubmed.ncbi.nlm.nih.gov/16382103/)
[Coetzee WA, Amarillo Y, Chiu J, et al, Molecular diversity of K+ channel function and structure (1999)](https://pubmed.ncbi.nlm.nih.gov/10099684/)
[Rudy B, Sen K, Vega-Beltrán J, et al, The Kv3 channels: voltage-gated K+ channels highly expressed in brain (1999)](https://pubmed.ncbi.nlm.nih.gov/10352670/)
[Hille B, Ion channels of excitable membranes (2001)](https://www.ncbi.nlm.nih.gov/books/NBK2016/)
[Nerbonne JM, Kass RS, Molecular physiology of cardiac repolarization (2005)](https://pubmed.ncbi.nlm.nih.gov/16183911/)
[Stocker M, Ca2+-activated K+ channels: molecular determinants and function (2004)](https://pubmed.ncbi.nlm.nih.gov/15165735/)
[Lesage F, et al. TWIK-1: a ubiquitous background potassium channel (1996)](https://pubmed.ncbi.nlm.nih.gov/8621702/)
[Goldstein SA, et al. K2P potassium channels: new functions (2001)](https://pubmed.ncbi.nlm.nih.gov/11712047/)
[Reyes R, et al. TWIK-1, a ubiquitous background K+ channel (1998)](https://pubmed.ncbi.nlm.nih.gov/9581669/)
[Talley EM, et al. Distribution of neuronal two-pore domain K+ channels (2001)](https://pubmed.ncbi.nlm.nih.gov/11505184/)
[Patel AJ, et al. TWIK-1 and TREK-1 are background K+ channels (2000)](https://pubmed.ncbi.nlm.nih.gov/10625713/)
[Aller MI, et al. Modulation of K2P channels by general anesthetics (2005)](https://pubmed.ncbi.nlm.nih.gov/15836884/)Pathway Diagram
The following diagram shows the key molecular relationships involving kcnk1 discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)
Pathway Diagram
The following diagram shows the key molecular relationships involving KCNK1 Gene - Two-Pore Domain Potassium Channel discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)