IPR003020
Bicarbonate transporter, eukaryotic
InterPro entry
Short name | HCO3_transpt_euk |
family relationships |
Description
Bicarbonate (HCO3-) transport mechanisms are the principal regulators of pH in animal cells. Such transport also plays a vital role in acid-base movements in the stomach, pancreas, intestine, kidney, reproductive organs and the central nervous system. Functional studies have suggested four different HCO3-transport modes. Anion exchanger proteins exchange HCO3-for Cl-in a reversible, electroneutral manner
[1]. Na+/HCO3-co-transport proteins mediate the coupled movement of Na+and HCO3-across plasma membranes, often in an electrogenic manner
[3]. Na+driven Cl-/HCO3-exchange and K+/HCO3-exchange activities have also been detected in certain cell types, although the molecular identities of the proteins responsible remain to be determined.
Sequence analysis of the two families of HCO3-transporters that have been cloned to date (the anion exchangers and Na+/HCO3-co-transporters) reveals that they are homologous. This is not entirely unexpected, given that they both transport HCO3-and are inhibited by a class of pharmacological agents called disulphonic stilbenes
[2]. They share around ~25-30% sequence identity, which is distributed along their entire sequence length, and have similar predicted membrane topologies, suggesting they have ~10 transmembrane (TM) domains.
References
1.Molecular biology of the anion exchanger gene family. Kopito RR. Int. Rev. Cytol. 123, 177-99, (1990). PMID: 2289848
2.Cloning and functional expression of a human kidney Na+:HCO3- cotransporter. Burnham CE, Amlal H, Wang Z, Shull GE, Soleimani M. J. Biol. Chem. 272, 19111-4, (1997). View articlePMID: 9235899
GO terms
biological process
molecular function
cellular component