NKE pump - The Physics of Physiology
ATPase pumps: NKE
Sodium potassium exchanger
This transporter allows entry of two potassium ion in exchange for the extrusion of three sodium ions from the cell, at the expense of ATP being hydrolysed to release energy for the process. The bond-graph model is illustrated in the figure below, with the CellML model added for simulation purposes.
The bond graph representation of the four state NKE model, showing simplification of the full bond graph into the reduced form.
The bond graph representation of the six state NKE model.
After clicking the CellML file, the Views Available menu to the right provides various options to explore this model here in the Physiome Model Repository. Of particular interest is the Launch with OpenCOR menu item, which will load the simulation experiment shown below directly into the OpenCOR desktop application.
Showing the result of launching the four state model simulation experiment from this exposure in OpenCOR and executing the simulation.
Showing the result of launching the six state model simulation experiment.
Protein knowledge
NKE is thought to be a heterodimer - made of the active alpha subunit protein, which catalyses the hydrolysis of ATP coupled with the exchange of sodium and potassium ions through the channel pore. This subunit is assembled with the regulatory beta subunit.
Subfamilies
The following list contains a portion of all subfamilies that can compose the NKE.
| Channel name | Alias | Gene | Structure |
|---|---|---|---|
| ATP1A1 | Uniprot A1 | PDB A1 | |
| ATP1A2 | Uniprot A2 | SMR A2 | |
| ATP1A3 | Uniprot A3 | PDB A3 | |
| ATP1A4 | Uniprot A4 | SMR A4 | |
| ATP1B1 | Uniprot B1 | PDB B1 | |
| ATP1B2 | Uniprot B2 | SMR B2 | |
| ATP1B3 | Uniprot B3 | SMR B3 | |
| ATP1C | ATNG, FXYD2 | Uniprot 1C | PDB 1C |
| FXYD3 | Uniprot FXYD3 | SMR FXYD3 |
Literature
| Title | Author |
|---|---|
| A computational model of induced pluripotent stem-cell derived cardiomyocytes incorporating experimental variability from multiple data sources | Kernik et al. |
| A thermodynamic framework for modelling membrane transporters | Pan et al. |
Existing models
| Title | Author |
|---|---|
| BG_NaK | S Fong |
| Cellular consequences of HERG mutations in the long QT syndrome: precursors to sudden cardiac death*^ | C Clancy and Y Rudy |
| Bond graph modelling of the cardiac action potential: Implications for drift and non-unique steady states^ | M Pan et al. |
| A Model of the Ventricular Cardiac Action Potential - Depolarisation, Repolarisation and Their Interaction*^ | C Luo and Y Rudy |
Models denoted by [*] are not in bond graph form. Models denoted by [^] are part of a whole cell model.
Other annotations
| Item | Database |
|---|---|
| Sodium:potassium-exchanging ATPase complex | Gene Ontology Complex |
| P-type sodium:potassium-exchanging transporter activity | Gene Ontology activity |