Page last updated: 2024-10-24
P-type sodium:potassium-exchanging transporter activity
Definition
Target type: molecularfunction
Enables the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: ATP + H2O + Na+(in) + K+(out) = ADP + phosphate + Na+(out) + K+(in). [EC:7.2.2.13]
P-type sodium:potassium-exchanging transporter activity is a fundamental process in cellular physiology, crucial for maintaining ion gradients across cell membranes. This activity is catalyzed by a family of transmembrane proteins known as Na+/K+ ATPases (sodium-potassium pumps). The pump utilizes the energy derived from ATP hydrolysis to move three sodium ions (Na+) out of the cell and two potassium ions (K+) into the cell, against their respective electrochemical gradients. This active transport process creates a net outward movement of positive charges, contributing to the maintenance of the membrane potential, which is essential for nerve impulse transmission, muscle contraction, and other cellular processes.
The molecular mechanism involves a series of conformational changes within the pump protein, driven by the binding and hydrolysis of ATP. The pump cycles through different conformations, exposing its ion binding sites alternately to the intracellular and extracellular fluids. In the initial state, the pump has a high affinity for Na+ ions on the intracellular side. Binding of three Na+ ions triggers ATP hydrolysis, leading to a conformational change that opens the ion binding sites to the extracellular side and increases the affinity for K+ ions. Two K+ ions bind from the extracellular side, and the dephosphorylation of the pump protein returns it to its initial conformation, releasing K+ ions into the intracellular compartment and making it ready to bind Na+ again.
The Na+/K+ ATPase is highly regulated by factors such as intracellular Na+ and K+ concentrations, membrane potential, and hormones. Its activity is crucial for maintaining cell volume, regulating neuronal excitability, and facilitating nutrient uptake. Dysfunction of this pump can lead to various pathological conditions, including muscle weakness, heart failure, and neurological disorders.'
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Proteins (8)
| Protein | Definition | Taxonomy |
|---|---|---|
| Sodium/potassium-transporting ATPase subunit alpha-1 | A sodium/potassium-transporting ATPase subunit alpha-1 that is encoded in the genome of dog. [OMA:P50997, PRO:DNx] | Canis lupus familiaris (dog) |
| Potassium-transporting ATPase alpha chain 1 | A potassium-transporting ATPase alpha chain 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P20648] | Homo sapiens (human) |
| Sodium/potassium-transporting ATPase subunit alpha-4 | A sodium/potassium-transporting ATPase subunit alpha-4 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q13733] | Homo sapiens (human) |
| Potassium-transporting ATPase alpha chain 2 | A potassium-transporting ATPase alpha chain 2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P54707] | Homo sapiens (human) |
| Sodium/potassium-transporting ATPase subunit alpha-2 | A sodium/potassium-transporting ATPase subunit alpha-2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P50993] | Homo sapiens (human) |
| Sodium/potassium-transporting ATPase subunit alpha-3 | A sodium/potassium-transporting ATPase subunit alpha-3 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P13637] | Homo sapiens (human) |
| Sodium/potassium-transporting ATPase subunit beta-1 | A sodium/potassium-transporting ATPase subunit beta-1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P05026] | Homo sapiens (human) |
| Sodium/potassium-transporting ATPase subunit alpha-1 | A sodium/potassium-transporting ATPase subunit alpha-1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P05023] | Homo sapiens (human) |
Compounds (19)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| cimetidine | cimetidine : A member of the class of guanidines that consists of guanidine carrying a methyl substituent at position 1, a cyano group at position 2 and a 2-{[(5-methyl-1H-imidazol-4-yl)methyl]sulfanyl}ethyl group at position 3. It is a H2-receptor antagonist that inhibits the production of acid in stomach. Cimetidine: A histamine congener, it competitively inhibits HISTAMINE binding to HISTAMINE H2 RECEPTORS. Cimetidine has a range of pharmacological actions. It inhibits GASTRIC ACID secretion, as well as PEPSIN and GASTRIN output. | aliphatic sulfide; guanidines; imidazoles; nitrile | adjuvant; analgesic; anti-ulcer drug; H2-receptor antagonist; P450 inhibitor |
| lansoprazole | Lansoprazole: A 2,2,2-trifluoroethoxypyridyl derivative of timoprazole that is used in the therapy of STOMACH ULCERS and ZOLLINGER-ELLISON SYNDROME. The drug inhibits H(+)-K(+)-EXCHANGING ATPASE which is found in GASTRIC PARIETAL CELLS. Lansoprazole is a racemic mixture of (R)- and (S)-isomers. | benzimidazoles; pyridines; sulfoxide | anti-ulcer drug; EC 3.6.3.10 (H(+)/K(+)-exchanging ATPase) inhibitor |
| omeprazole | 5-methoxy-2-{[(4-methoxy-3,5-dimethylpyridin-2-yl)methyl]sulfinyl}-1H-benzimidazole : A member of the class of benzimidazoles that is 1H-benzimidazole which is substituted by a [4-methoxy-3,5-dimethylpyridin-2-yl)methyl]sulfinyl group at position 2 and a methoxy group at position 5. omeprazole : A racemate comprising equimolar amounts of (R)- and (S)-omeprazole. Omeprazole: A 4-methoxy-3,5-dimethylpyridyl, 5-methoxybenzimidazole derivative of timoprazole that is used in the therapy of STOMACH ULCERS and ZOLLINGER-ELLISON SYNDROME. The drug inhibits an H(+)-K(+)-EXCHANGING ATPASE which is found in GASTRIC PARIETAL CELLS. | aromatic ether; benzimidazoles; pyridines; sulfoxide | |
| pantoprazole | pantoprazole : A member of the class of benzimidazoles that is 1H-benzimidazole substituted by a difluoromethoxy group at position 5 and a [(3,4-dimethoxypyridin-2-yl)methyl]sulfinyl group at position 2. Pantoprazole: 2-pyridinylmethylsulfinylbenzimidazole proton pump inhibitor that is used in the treatment of GASTROESOPHAGEAL REFLUX and PEPTIC ULCER. | aromatic ether; benzimidazoles; organofluorine compound; pyridines; sulfoxide | anti-ulcer drug; EC 3.6.3.10 (H(+)/K(+)-exchanging ATPase) inhibitor; environmental contaminant; xenobiotic |
| ranitidine | aralkylamine | ||
| digoxigenin | digoxigenin : A hydroxy steroid that consists of 5beta-cardanolide having a double bond at the 20(22)-position as well as hydroxy groups at the 3beta-, 12beta- and 14beta-positions. It has been isolated from the plant species of the genus Digitalis. Digoxigenin: 3 beta,12 beta,14-Trihydroxy-5 beta-card-20(22)-enolide. A cardenolide which is the aglycon of digoxin. Can be obtained by hydrolysis of digoxin or from Digitalis orientalis L. and Digitalis lanata Ehrh. | 12beta-hydroxy steroid; 14beta-hydroxy steroid; 3beta-hydroxy steroid; 3beta-sterol | hapten; plant metabolite |
| timoprazole | timoprazole: gastric acid secretion inhibitor | ||
| digoxigenin-bis(digitoxoside) | cardenolide glycoside | ||
| 2-((2-dimethylaminobenzyl)sulfinyl)benzimidazole | 2-((2-dimethylaminobenzyl)sulfinyl)benzimidazole: structure given in first source | ||
| rostafuroxin | rostafuroxin: structure in first source | ||
| ouabain | cardiac glycoside : Steroid lactones containing sugar residues that act on the contractile force of the cardiac muscles. ouabain : A steroid hormone that is a multi-hydroxylated alpha-L-rhamnosyl cardenoloide. It binds to and inhibits the plasma membrane Na(+)/K(+)-ATPase (sodium pump). It has been isolated naturally from Strophanthus gratus. Ouabain: A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE. | 11alpha-hydroxy steroid; 14beta-hydroxy steroid; 5beta-hydroxy steroid; alpha-L-rhamnoside; cardenolide glycoside; steroid hormone | anti-arrhythmia drug; cardiotonic drug; EC 2.3.3.1 [citrate (Si)-synthase] inhibitor; EC 3.1.3.41 (4-nitrophenylphosphatase) inhibitor; EC 3.6.3.10 (H(+)/K(+)-exchanging ATPase) inhibitor; EC 3.6.3.9 (Na(+)/K(+)-transporting ATPase) inhibitor; ion transport inhibitor; plant metabolite |
| digitoxin | digitoxin : A cardenolide glycoside in which the 3beta-hydroxy group of digitoxigenin carries a 2,6-dideoxy-beta-D-ribo-hexopyranosyl-(1->4)-2,6-dideoxy-beta-D-ribo-hexopyranosyl-(1->4)-2,6-dideoxy-beta-D-ribo-hexopyranosyl trisaccharide chain. Digitoxin: A cardiac glycoside sometimes used in place of DIGOXIN. It has a longer half-life than digoxin; toxic effects, which are similar to those of digoxin, are longer lasting. (From Martindale, The Extra Pharmacopoeia, 30th ed, p665) | cardenolide glycoside | EC 3.6.3.9 (Na(+)/K(+)-transporting ATPase) inhibitor |
| digoxin | digoxin : A cardenolide glycoside that is digitoxin beta-hydroxylated at C-12. A cardiac glycoside extracted from the foxglove plant, Digitalis lanata, it is used to control ventricular rate in atrial fibrillation and in the management of congestive heart failure with atrial fibrillation, but the margin between toxic and therapeutic doses is small. Digoxin: A cardiotonic glycoside obtained mainly from Digitalis lanata; it consists of three sugars and the aglycone DIGOXIGENIN. Digoxin has positive inotropic and negative chronotropic activity. It is used to control ventricular rate in ATRIAL FIBRILLATION and in the management of congestive heart failure with atrial fibrillation. Its use in congestive heart failure and sinus rhythm is less certain. The margin between toxic and therapeutic doses is small. (From Martindale, The Extra Pharmacopoeia, 30th ed, p666) | cardenolide glycoside; steroid saponin | anti-arrhythmia drug; cardiotonic drug; EC 3.6.3.9 (Na(+)/K(+)-transporting ATPase) inhibitor; epitope |
| digitoxigenin | digitoxigenin : A 5beta-cardenolide that is 5beta-cardanolide with hydroxy substituents at the 3beta- and 14beta-positions and double bond unsaturation at C(20)-C(22). Digitoxigenin: 3 beta,14-Dihydroxy-5 beta-card-20(22)enolide. A cardenolide which is the aglycon of digitoxin. Synonyms: Cerberigenin; Echujetin; Evonogenin; Thevetigenin. | 14beta-hydroxy steroid; 3beta-hydroxy steroid | |
| istaroxime | Istaroxime: PST-2744 is the (E,Z)-isomer; a positive cardiac inotropic agent; structure in first source | ||
| phakellistatin 2 | phakellistatin 2: isolated from the marine sponge Phakellia carteri; structure in first source | ||
| digitoxigenin monodigitoxoside | digitoxigenin monodigitoxoside: RN given refers to (ribo-3beta,5beta)-isomer | ||
| evomonoside | evomonoside : A cardenolide glycoside consisting of digitoxigenin having an alpha-L-rhamnosyl moiety attached at the O(3)-position. evomonoside: a cytotoxic cardiac glycoside from Lepidium apetalum; RN refers to (3beta,5beta)-isomer | cardenolide glycoside | |
| halisulfate 1 | halisulfate 1: an isocitrate lyase inhibitor sesterterpene sulfate from sponge, Hippospongia sp.; structure in first source | organic molecular entity | metabolite |