Na+/K+ ATPase Alpha-1 Subunit
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ATP1A1 Protein is a protein encoded by the ATP1A1 gene. This page describes its structure, normal nervous system function, role in neurodegenerative disease, and potential as a therapeutic target.
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| Protein Name | Na+/K+ ATPase Alpha-1 Subunit |
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| Gene | [ATP1A1](/genes/atp1a1) |
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| UniProt ID | [P05023](https://www.uniprot.org/uniprot/P05023) |
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| PDB Structures | [3WGU](https://www.rcsb.org/structure/3WGU), [5KUG](https://www.rcsb.org/structure/5KUG), [6MRB](https://www.rcsb.org/structure/6MRB) |
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| Molecular Weight | ~112 kDa |
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| Subcellular Localization | Plasma membrane |
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| Protein Family | P-type ATPase (E1-E2 ATPase family) |
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The Na+/K+ ATPase is a heteromeric protein consisting of an alpha (catalytic), beta, and gamma (or FXYD) subunit. The alpha-1 subunit is the largest component (~1000 amino acids) and contains:
- 10 transmembrane helices (M1-M10) that form the ion channel
- ATP-binding domain (N/P domains) in the cytoplasmic region
- Pump specificity determinants for Na+ and K+ ion binding
- Ouabain-binding site on the extracellular face
The E1-E2 conformational cycle involves phosphorylation of an aspartate residue in the P-domain, driving conformational changes that alternate ion binding affinity from high (E1) to low (E2) states.
In neurons and glial cells, the Na+/K+ ATPase maintains:
- Resting membrane potential (-70 to -90 mV) via electrogenic 3Na+/2K+ exchange
- Ion gradients essential for action potential propagation
- Volume homeostasis preventing cellular swelling
- Secondary transport - drives glutamate reuptake via EAAT transporters
- Calcium homeostasis - indirectly regulates Ca2+ via Na+/Ca2+ exchanger activity
- Signal transduction - activates Src kinase signaling cascades
The alpha-1 subunit is the ubiquitous isoform, expressed in most cell types including neurons, astrocytes, and oligodendrocytes.
- Amyloid-beta toxicity: Aβ oligomers directly inhibit Na+/K+ ATPase activity in hippocampal neurons [1]
- Energy failure: Reduced ATPase activity contributes to neuronal hyperexcitability and vulnerability
- Calcium dysregulation: Impaired Na+ gradient affects NCX function, leading to calcium overload
- Therapeutic relevance: Cardiac glycosides (digoxin, ouabain) that inhibit Na+/K+ ATPase show complex effects in AD models [2]
- Alpha-synuclein interaction:研究发现α-突触核蛋白聚集体可以抑制Na+/K+ ATPase活性
- Mitochondrial dysfunction: Energy deficits compound complex I deficiency in PD
- Neuronal vulnerability: Dopaminergic neurons show particular sensitivity to ATPase inhibition
- Motor neuron vulnerability: Motor neurons rely heavily on precise ion homeostasis
- Excitotoxicity: Impaired glutamate uptake due to gradient disruption contributes to excitotoxic cell death
- Energy metabolism: ALS motor neurons show metabolic vulnerabilities that ATPase dysfunction compounds
¶ Stroke and Ischemia
- Ischemic injury: Na+/K+ ATPase failure is an early event in ischemic neuronal death
- Reperfusion damage: Restoring ATPase function is crucial for neuronal recovery
- Therapeutic target: Na+/K+ ATPase modulators are being investigated for neuroprotection [3]
- Cardiac glycosides: Digoxin, ouabain - show neuroprotective effects in some studies but narrow therapeutic window
- Novel inhibitors: Safer analogs being developed for specific neuroprotective applications
- FXYD proteins: Regulatory subunits (FXYD1-10) offer targeting opportunities for isoform-specific modulation
- Stroke therapy: Na+/K+ ATPase activation/protection strategies in development
- Neurodegeneration: Understanding ATPase dysfunction provides insights into energy failure mechanisms
| Interactor |
Function |
Reference |
| ATP1B1 |
Beta-1 subunit - required for proper folding and membrane localization |
4 |
| FXYD proteins |
Regulatory subunits modulating pump kinetics |
5 |
| Src kinase |
Na+/K+ ATPase activates Src signaling cascades |
6 |
| Alpha-synuclein |
PD-linked protein inhibits ATPase function |
7 |
| Amyloid-beta |
Aβ oligomers inhibit ATPase activity |
1 |