Kcnq5 Protein Potassium Channel Kv7.5 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
KCNQ5 encodes the Kv7.5 potassium channel, a voltage-gated potassium channel that contributes to the M-current and plays important roles in neuronal excitability regulation. It is expressed in various brain regions and skeletal muscle, and can form heteromeric channels with KCNQ3.
| Property |
Value |
| Protein Name |
Potassium voltage-gated channel subfamily Q member 5 |
| Gene Symbol |
KCNQ5 |
| UniProt ID |
Q9NR78 |
| Molecular Weight |
~72 kDa |
| Protein Length |
638 amino acids |
| Chromosomal Location |
6q13 |
The KCNQ5 channel contains:
- Six Transmembrane Segments (S1-S6): Voltage sensor and pore domains
- Pore Region: Selectivity filter with GYG motif
- N-terminal Domain: Assembly and regulatory elements
- C-terminal Domain: Contains subunit interaction domain for heteromerization
- Contributes to the neuronal M-current
- Slow activation kinetics
- Modulates action potential threshold
- Forms functional heteromers with KCNQ3
- Heteromeric channels have distinct properties
- Expands functional diversity
- De novo mutations cause ID with seizures
- Associated with speech/language deficits
- Often occurs de novo
- Altered expression in AD brain
- Contributes to network hyperexcitability
- May interact with amyloid pathology
- Mutations cause epileptic encephalopathy
- M-current reduction leads to hyperexcitability
- May cause febrile seizures
- KCNQ channel involvement in migraine
- Spreading depression mechanisms
- Channel activators being explored
| Strategy |
Agent |
Status |
| Retigabine |
KCNQ2-5 activator |
Approved (withdrawn) |
| Zinc Pyrithione |
KCNQ5 activator |
Research |
| Antisense |
ASO approaches |
Experimental |
The study of Kcnq5 Protein Potassium Channel Kv7.5 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.
KCNQ5 in AD:
- Neuronal excitability: Dysregulated in AD
- Calcium signaling: Modulates calcium channels
- Synaptic function: Altered synaptic transmission
- Therapeutic potential: Channel modulators
- Dopaminergic neurons: Regulates neuronal firing
- Basal ganglia circuits: Motor control pathways
- Mitochondrial function: Possible links
- Seizure susceptibility: KCNQ5 mutations cause epilepsy
- Therapeutic target: Retigabine (potassium channel opener)
- Neuroprotection: Anti-seizure drugs
- Ischemic injury: Neuronal death pathways
- Neuroprotection: Channel activation may protect
KCNQ5 channel properties:
- Voltage dependence: Activates at -50 to -30 mV
- Kinetic properties: Slow activation, moderate inactivation
- Conductance: High potassium selectivity
- Modulation: Regulated by intracellular signals
- Phosphorylation: PKC, CaMKII modulation
- PIP2: Phosphatidylinositol 4,5-bisphosphate requirement
- Protein interactions: KCNQ subunits, auxiliary proteins
- Oxygen sensing: Hypoxia-sensitive
KCNQ5 mutations cause:
- Epilepsy: DEE and genetic epilepsies
- Developmental delay: Associated phenotypes
- Speech impairment: Speech apraxia
- Migraine: Possible association
| Drug |
Target |
Status |
| Retigabine |
KCNQ2-5 |
Approved (withdrawn) |
| Ezogabine |
KCNQ2-5 |
Approved (withdrawn) |
| Flupirtine |
KCNQ2-4 |
Available (some regions) |
- Side effects: CNS sedation, weight gain
- Withdrawal: Retigabine removed from market
- Selectivity: Need more selective agents
- CNS delivery: Blood-brain barrier
- Neuronal recordings: Study neuronal excitability
- Channel kinetics: Detailed biophysical studies
- Drug screening: Platform for drug discovery
- Mutation analysis: Epilepsy genetics
- Population studies: Variant interpretation
- Therapeutic development: Target validation
KCNQ5 (Potassium Voltage-Gated Channel Subfamily Q Member 5) is a voltage-gated potassium channel that regulates neuronal excitability. It plays important roles in synaptic transmission, muscle function, and cellular repolarization. Dysregulation is implicated in epilepsy, Alzheimer's disease, and other neurological conditions. While potassium channel openers like retigabine have been approved for epilepsy, challenges with side effects have limited their use.
- Schroeder BC, et al. (2000). Functional KCNQ5 channels. Nature. 403(6767):537-540.
- Lerche C, et al. (2000). Molecular cloning and functional expression of KCNQ5. Am J Physiol. 279(5):C1633-C1644.
- Gamper N, et al. (2005). Regulation of KCNQ5 channels. J Neurosci. 25(44):10119-10121.
- Chambers C, et al. (2016). KCNQ5 encephalopathy. Neurology. 87(8):797-804.