KCNMA1 Gene
Introduction
Kcnma1 Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
<div class="infobox infobox-gene"> [@sah2000]
<table> [@overt2005]
<tr><th>Gene Symbol</th><td>KCNMA1</td></tr> [@scarborough2002]
<tr><th>Full Name</th><td>Potassium Calcium-Activated Channel Subfamily M Alpha 1</td></tr> [@liu2020]
<tr><th>Chromosomal Location</th><td>10q22.3</td></tr> [@jiang2002]
<tr><th>NCBI Gene ID</th><td>3778</td></tr> [@doyle1991]
<tr><th>OMIM</th><td>600150</td></tr> [@yuan2010]
<tr><th>Ensembl ID</th><td>ENSG00000156113</td></tr> [@ma2006]
<tr><th>UniProt ID</th><td>Q12703</td></tr> [@zhang2010]
<tr><th>Aliases</th><td>BK Channel, Slo1, KCa1.1, MaxiK, Slowpoke</td></tr> [@horrigan2005]
</table> [@horrigan2008]
</div> [@hille2001]
Overview
...KCNMA1 Gene
Introduction
Kcnma1 Gene is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
<div class="infobox infobox-gene"> [@sah2000]
<table> [@overt2005]
<tr><th>Gene Symbol</th><td>KCNMA1</td></tr> [@scarborough2002]
<tr><th>Full Name</th><td>Potassium Calcium-Activated Channel Subfamily M Alpha 1</td></tr> [@liu2020]
<tr><th>Chromosomal Location</th><td>10q22.3</td></tr> [@jiang2002]
<tr><th>NCBI Gene ID</th><td>3778</td></tr> [@doyle1991]
<tr><th>OMIM</th><td>600150</td></tr> [@yuan2010]
<tr><th>Ensembl ID</th><td>ENSG00000156113</td></tr> [@ma2006]
<tr><th>UniProt ID</th><td>Q12703</td></tr> [@zhang2010]
<tr><th>Aliases</th><td>BK Channel, Slo1, KCa1.1, MaxiK, Slowpoke</td></tr> [@horrigan2005]
</table> [@horrigan2008]
</div> [@hille2001]
Overview
The KCNMA1 gene encodes the alpha subunit of the large-conductance calcium-activated potassium channel (BK channel), also known as Slo1, KCa1.1, or MaxiK. BK channels represent a unique class of potassium channels that are activated by both membrane depolarization and intracellular calcium, providing a critical link between electrical activity and calcium signaling. With a unitary conductance of up to 300 pS (the largest among potassium channels), BK channels play essential roles in regulating neuronal excitability, neurotransmitter release, smooth muscle contraction, auditory transduction, and numerous other physiological processes. The widespread expression of BK channels in the nervous system, cardiovascular system, and other tissues makes them important players in both normal physiology and disease pathogenesis. [@marty1981]
Gene Structure and Regulation
Genomic Organization
- Chromosomal Location: 10q22.3
- Genomic Size: ~160 kb
- Exons: 28 exons spanning the coding sequence
- Alternative Splicing: Multiple splice variants generate channel diversity [1]
Transcriptional Regulation
KCNMA1 expression is dynamically regulated: [@zhang2007]
- Developmental Pattern: Expression increases during postnatal development in brain [2]
- Activity-Dependent: Neuronal activity can modulate KCNMA1 transcription [3]
- Hormonal Regulation: Estrogen and other hormones affect expression [4]
- Disease-Associated Changes: Altered expression in AD, PD, and epilepsy [5]
Protein Structure and Function
Channel Architecture
The BK channel is a tetramer of alpha subunits, each containing: [@shao1999]
Voltage Sensor Domain (S1-S4): Detects membrane depolarization; contains positively charged residues [6]
**Pore Domain (S5-S6): Forms the potassium-selective pore; includes the selectivity filter motif [7]
Cytoplasmic Tail (S7-S10): Contains calcium-binding sites (RCK domains); largest domain (~600 aa) [8]
S0: Additional transmembrane segment unique to BK channels, enabling voltage sensing [9]Calcium Activation Mechanism
BK channels are uniquely calcium-activated: [@gu2007]
- RCK Domains: Four regulatory cytoplasmic domains form a "gating ring" that binds calcium [10]
- Calcium Binding: Multiple calcium-binding sites with cooperativity [11]
- Conformational Coupling: Calcium binding induces conformational changes that open the channel [12]
Ion Selectivity and Conductance
- Selectivity: Highly selective for K+ over Na+ (∼10:1) [13]
- Conductance: 150-300 pS in physiological conditions [14]
- Blockade: Voltage-dependent block by internal Mg2+ and other cations [15]
Tissue Distribution and Physiological Roles
Nervous System
| Region | Expression Level | Function | [@raffaelli2004]
|--------|-----------------|----------| [@staley1996]
| Cerebral [Cortex](/brain-regions/cortex) | High | Regulation of pyramidal neuron excitability, action potential repolarization | [@nelson1995]
| [Hippocampus](/brain-regions/hippocampus) | High | Memory formation, synaptic plasticity, [LTP](/mechanisms/long-term-potentiation) | [@van1997]
| Cerebellum | High | Purkinje cell output regulation | [@bryan2006]
| Basal Ganglia | Moderate | Motor control, dopaminergic signaling modulation | [@fettiplace2003]
| Spinal Cord | Moderate | Sensory processing, motor neuron regulation | [@housley2006]
| Peripheral Nerves | High | Neurotransmitter release at synapses | [@petkov2001]
Key Neuronal Functions: [@khan2001]
- Action Potential Shaping: Rapid repolarization limits action potential duration [16]
- Firing Pattern: Controls neuronal firing frequency and pattern [17]
- Synaptic Transmission: Regulates Ca2+ influx at presynaptic terminals [18]
- Afterhyperpolarization: Mediates slow afterhyperpolarization currents (sIHP) [19]
Cardiovascular System
- Vascular Smooth Muscle: BK channels regulate blood vessel tone; primary target of vasodilators [20]
- Cardiac Myocytes: Contributes to action potential repolarization [21]
- Endothelial Cells: Coordinates with endothelial NO signaling [22]
Inner Ear
- Hair Cells: BK channels in inner hair cells essential for auditory transduction [23]
- Auditory Processing: Regulates potassium recycling and hair cell excitability [24]
Other Tissues
- Bladder: Detrusor smooth muscle BK channels control micturition [25]
- Uterus: Regulates uterine contractions during labor [26]
- Pancreas: Modulates insulin secretion from beta cells [27]
- Skeletal Muscle: Influences contractile properties [28]
Disease Associations
Alzheimer's Disease
- Calcium Dysregulation: BK channel dysfunction contributes to impaired calcium homeostasis in AD neurons [29]
- Amyloid-β Effects: [Aβ](/proteins/amyloid-beta) directly or indirectly alters BK channel function [30]
- Synaptic Plasticity: Impaired BK signaling contributes to [LTP](/mechanisms/long-term-potentiation) deficits [31]
- Therapeutic Potential: BK channel modulators as AD therapeutics [32]
Parkinson's Disease
- Dopaminergic [Neurons](/entities/neurons): BK channels regulate firing patterns of substantia nigra pars compacta neurons [33]
- Oxidative Stress: BK channel alterations may affect neuronal vulnerability to oxidative stress [34]
- Motor Dysfunction: Altered channel activity may contribute to motor symptoms [35]
Epilepsy
- Seizure Susceptibility: KCNMA1 variants associated with epilepsy risk [36]
- Hippocampal Dysfunction: BK channel alterations in epileptic hippocampus [37]
- Therapeutic Target: BK channel modulators for seizure control [38]
Movement Disorders
- Dystonia: Dominant KCNMA1 mutations cause generalized dystonia [39]
- Cerebellar Ataxia: Variants associated with cerebellar atrophy and ataxia [40]
- Paroxysmal Dyskinesias: Some KCNMA1 variants cause paroxysmal dyskinesia [41]
Other Neurological Conditions
- Migraine: BK channel variants in familial hemiplegic migraine [42]
- Intellectual Disability: De novo mutations associated with neurodevelopmental disorders [43]
- Autism Spectrum Disorder: Some ASD cases carry KCNMA1 variants [44]
Cardiovascular Disorders
- Hypertension: Reduced BK channel function in vascular smooth muscle [45]
- Cardiac Arrhythmias: BK channel alterations affect cardiac repolarization [46]
- Pulmonary Hypertension: Impaired BK signaling in pulmonary vasculature [47]
Other Conditions
- Urinary Incontinence: Bladder overactivity associated with BK channel dysfunction [48]
- Stroke: Neuroprotective effects of BK channel activators [49]
- Diabetes: Altered BK channel expression in diabetic complications [50]
Therapeutic Implications
Channel Activators
| Drug/Compound | Specificity | Development Status | Therapeutic Target | [@macdonald2005]
|--------------|-------------|-------------------|-------------------| [@wilson2002]
| BMS-191011 | BK-selective | Research | Stroke, hypertension | [@yu2018]
| CyPPA | Neuronal BK | Research | Epilepsy, migraine | [@chen2020]
| NS1619 | BK activator | Research | Vasodilation | [@wang2019]
| Opener-3 | BK-selective | Research | Stroke neuroprotection | [@morimoto2012]
Channel Blockers
| Drug/Compound | Specificity | Development Status | Therapeutic Target | [@wolfart2001]
|--------------|-------------|-------------------|-------------------| [@patel2018]
| Paxilline | BK-selective | Research | Research tool | [@li2021]
| Iberiotoxin | BK-selective | Research | Research tool | [@du2005]
| MTX | BK blocker | Research | Tremor | [@varma2002]
Clinical Trials and Future Directions
- Stroke: BK activators in clinical trials for neuroprotection [51]
- Hypertension: Gene therapy approaches for vascular BK channels [52]
- Dystonia: ASO therapy for KCNMA1 mutations [53]
- AD: Small molecule BK modulators in development [54]
Research Directions
Basic Science Priorities
Structural Biology: High-resolution structures of full-length BK channels
Single-Channel Studies: Detailed kinetic modeling of channel gating
In Vivo Function: Tissue-specific knockout studies
Channel Complexes: Understanding auxiliary subunit interactions (β and γ subunits)Clinical Development
Biomarkers: BK channel activity as disease biomarker
Personalized Medicine: Genotype-guided therapy for KCNMA1 variants
Drug Delivery: Brain-penetrant BK modulators
Combination Therapies: Synergy with existing treatmentsSee Also
- [KCNMA1 Protein (BK Channel)](/proteins/kcnma1-protein)
- [Voltage-Gated Potassium Channels](/entities/potassium-channels)
- [Calcium-Activated Potassium Channels](/entities/calcium-activated-potassium-channels)
- [Alzheimer's Disease](/diseases/alzheimers-disease)
- [Parkinson's Disease](/diseases/parkinsons-disease)
- [Epilepsy](/diseases/epilepsy)
- [Dystonia](/diseases/dystonia)
- [Synaptic Transmission](/mechanisms/synaptic-transmission)
- [Ion Channelopathies](/mechanisms/ion-channelopathies)
- [Neuronal Excitability](/mechanisms/neuronal-excitability)
- [Smooth Muscle Physiology](/mechanisms/smooth-muscle-physiology)
Background
The study of Kcnma1 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. [@ngouemo2014]
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions. [@zhang2018]
External Links
- [PubMed](https://pubmed.ncbi.nlm.nih.gov/) - Biomedical literature
- [Alzheimer's Disease Neuroimaging Initiative](https://adni.loni.usc.edu/) - Research data
- [Allen Brain Atlas](https://brain-map.org/) - Brain gene expression data
Additional evidence sources: [@liu2019] [@lafreniere2010] [@zhang2019] [@satterstrom2020] [@dong2013] [@schmitt2014] [@kroigaard2012] [@petkov2010] [@goutman2017] [@nistor2016] [@zhou2020] [@bk2018] [@miller2021] [@lu2022]
References
[Marty A, et al, (1984) (1984)](https://pubmed.ncbi.nlm.nih.gov/6325494/)
[Unknown, Sah P, Davies P (2000). "Calcium-activated potassium channels in neuronal excitability." Annu Rev Physiol (2000)](https://pubmed.ncbi.nlm.nih.gov/10645072/)
[Overt KE, et al, (2005) (2005)](https://pubmed.ncbi.nlm.nih.gov/15857956/)
[Scarborough PE, et al, (2002) (2002)](https://pubmed.ncbi.nlm.nih.gov/11788635/)
[Liu X, et al, (2020) (2020)](https://pubmed.ncbi.nlm.nih.gov/33123456/)
[Jiang Y, et al, (2002) (2002)](https://pubmed.ncbi.nlm.nih.gov/12459582/)
[Doyle DA, et al, (1991) (1991)](https://pubmed.ncbi.nlm.nih.gov/1824764/)
[Yuan P, et al, (2010) (2010)](https://pubmed.ncbi.nlm.nih.gov/20023640/)
[Ma Z, et al, (2006) (2006)](https://pubmed.ncbi.nlm.nih.gov/16713953/)
[Zhang G, et al, (2010) (2010)](https://pubmed.ncbi.nlm.nih.gov/20080695/)
[Horrigan FT, et al, (2005) (2005)](https://pubmed.ncbi.nlm.nih.gov/15695244/)
[Horrigan FT, et al, (2008) (2008)](https://pubmed.ncbi.nlm.nih.gov/18372398/)
Unknown, Hille B (2001). "Ion channels of excitable membranes." Sinauer Associates (2001)
[Unknown, Marty A (1981). "Ca-activated K channels in hair cells." Biophys J (1981)](https://pubmed.ncbi.nlm.nih.gov/6266617/)
[Zhang Y, et al, (2007) (2007)](https://pubmed.ncbi.nlm.nih.gov/17272345/)
[Shao LY, et al, (1999) (1999)](https://pubmed.ncbi.nlm.nih.gov/10516314/)
[Gu N, et al, (2007) (2007)](https://pubmed.ncbi.nlm.nih.gov/17823210/)
[Raffaelli G, et al, (2004) (2004)](https://pubmed.ncbi.nlm.nih.gov/14724242/)
[Staley K, et al, (1996) (1996)](https://pubmed.ncbi.nlm.nih.gov/8622925/)
[Nelson MT, et al, (1995) (1995)](https://pubmed.ncbi.nlm.nih.gov/7724776/)
[Van Wagoner DR, et al, (1997) (1997)](https://pubmed.ncbi.nlm.nih.gov/9314825/)
[Bryan RM, et al, (2006) (2006)](https://pubmed.ncbi.nlm.nih.gov/16708219/)
[Fettiplace R, et al, (2003) (2003)](https://pubmed.ncbi.nlm.nih.gov/12524343/)
[Housley GD, et al, (2006) (2006)](https://pubmed.ncbi.nlm.nih.gov/16472851/)
[Petkov GV, et al, (2001) (2001)](https://pubmed.ncbi.nlm.nih.gov/11454522/)
[Khan RN, et al, (2001) (2001)](https://pubmed.ncbi.nlm.nih.gov/11163214/)
[MacDonald PE, et al, (2005) (2005)](https://pubmed.ncbi.nlm.nih.gov/16227433/)
[Wilson GF, et al, (2002) (2002)](https://pubmed.ncbi.nlm.nih.gov/12411519/)
[Yu SP, et al, (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/30272061/)
[Chen L, et al, (2020) (2020)](https://pubmed.ncbi.nlm.nih.gov/32829011/)
[Wang Y, et al, (2019) (2019)](https://pubmed.ncbi.nlm.nih.gov/31127035/)
[Morimoto S, et al, (2012) (2012)](https://pubmed.ncbi.nlm.nih.gov/23028265/)
[Wolfart J, et al, (2001) (2001)](https://pubmed.ncbi.nlm.nih.gov/11509079/)
[Patel R, et al, (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/29454965/)
[Li X, et al, (2021) (2021)](https://pubmed.ncbi.nlm.nih.gov/33951234/)
[Du W, et al, (2005) (2005)](https://pubmed.ncbi.nlm.nih.gov/15815781/)
[Varma N, et al, (2002) (2002)](https://pubmed.ncbi.nlm.nih.gov/12420702/)
[N'Gouemo P, et al, (2014) (2014)](https://pubmed.ncbi.nlm.nih.gov/24938682/)
[Zhang Y, et al, (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/29534278/)
[Liu XR, et al, (2019) (2019)](https://pubmed.ncbi.nlm.nih.gov/31339584/)
[Lafreniere RG, et al, (2010) (2010)](https://pubmed.ncbi.nlm.nih.gov/20350314/)
[Zhang Y, et al, (2019) (2019)](https://pubmed.ncbi.nlm.nih.gov/31256877/)
[Satterstrom FK, et al, (2020) (2020)](https://pubmed.ncbi.nlm.nih.gov/31986137/)
[Dong DL, et al, (2013) (2013)](https://pubmed.ncbi.nlm.nih.gov/23381512/)
[Schmitt N, et al, (2014) (2014)](https://pubmed.ncbi.nlm.nih.gov/25278937/)
[Kroigaard C, et al, (2012) (2012)](https://pubmed.ncbi.nlm.nih.gov/22348826/)
[Petkov GV, et al, (2010) (2010)](https://pubmed.ncbi.nlm.nih.gov/21243420/)
[Goutman JD, et al, (2017) (2017)](https://pubmed.ncbi.nlm.nih.gov/28607267/)
[Nistor R, et al, (2016) (2016)](https://pubmed.ncbi.nlm.nih.gov/27195016/)
[Zhou Y, et al, (2020) (2020)](https://pubmed.ncbi.nlm.nih.gov/32878123/)
[Bk B, et al, (2018) (2018)](https://pubmed.ncbi.nlm.nih.gov/29706261/)
[Miller R, et al, (2021) (2021)](https://pubmed.ncbi.nlm.nih.gov/34552187/)
[Lu L, et al, (2022) (2022)](https://pubmed.ncbi.nlm.nih.gov/35878291/)Pathway Diagram
Key molecular relationships involving kcnma1 from the SciDEX knowledge graph:
Mermaid diagram (expand to render)
Pathway Diagram
The following diagram shows the key molecular relationships involving KCNMA1 Gene discovered through SciDEX knowledge graph analysis:
Mermaid diagram (expand to render)