3 Ontology Annotations
| GO Term | Gene Name |
|---|---|
| GO:0005215 | IPR002443 |
| GO:0006811 | IPR002443 |
| GO:0016020 | IPR002443 |
| Type: | Family | Name: | Na/K/Cl co-transporter |
| Description: | The Na-K-Cl co-transporters are a family of integral membrane proteins that are ubiquitously expressed in animal tissues, serving a variety offunctions. In cells of Cl-absorptive and Cl-secretory epithelia, Na-K-Cl co-transport serves as the major Cl-entry pathway, and functions in concert with other membrane ion channels and pumps to carry out nettransepithelial movement of salt. This vectorial transport of Cl-across epithelia is involved in the reabsorption of salt in the vertebrate kidney(which is crucial for urinary concentration), and in the secretion of salt in such tissues as the mammalian intestine and trachea. In addition,Na-K-Cl co-transport is known to play a role in cell volume regulation in most mammalian cell types. The proteins mediate the coupled, electroneutraltransport of sodium, potassium and chloride ions across the plasma membrane of cells (with a stoichiometry of 1:1:2, respectively). Co-transport of allthree ions is obligatory, since absence of one is sufficient to prevent ion movement. Their transport activity does not alter the cell's membranepotential, thus the driving force for the transport is determined solely by the chemical gradients of the three transported ions; hence, undernormal physiological conditions, the direction will be inward.Recent molecular studies have identified two distinct isoforms: one from Cl-secretory epithelia, NKCC1; and another, NKCC2, found specifically in the diluting segment of the vertebrate kidney, a Cl-absorptive epithelium []. They show lowish amino acid sequence identity (~58%); nevertheless,they have rather similar hydropathy profiles, with hydrophilic N- and C-termini, flanking a central hydrophobic domain. Their N-termini showconsiderable variation, unlike the central domain (containing the 12 putative transmembrane (TM) domains) and their C-termini, which are wellconserved (~70%). Both isoforms are known to be glycosylated and, consistent with this, consensus sites for N-linked glycosylation are located within thelarge hydrophilic loop between presumed TM domains 7 and 8. Sequence comparisons with other cloned ion co-transporters reveals that Na-K-Clco-transporters belong to a superfamily of electroneutral cation-chloride co-transporters, which includes the K-Cl co-transporter () and the thiazide-sensitive Na-Cl co-transporter. All share a similar predictedmembrane topology of 12 TM regions in a central hydrophobic domain, together with hydrophilic N- and C-termini that are likely cytoplasmic.Mutations in the gene encoding the renal-specific isoform of the Na-K-Cl co-transporter (NKCC2) give rise to Bartter's Syndrome Type 1, an inheritedkidney disease characterised by hypokalaemia, metabolic alkalosis, salt-wasting and hypotension []. | Short Name: | Na/K/Cl_cotranspt |
| GO Term | Gene Name |
|---|---|
| GO:0005215 | IPR002443 |
| GO:0006811 | IPR002443 |
| GO:0016020 | IPR002443 |
