Domain

Bicarbonate transporter, C-terminal (IPR011531)

Short name: HCO3_transpt_C

Domain relationships

None.

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 [PMID: 2289848]. Na+/HCO3- co-transport proteins mediate the coupled movement of Na+ and HCO3- across plasma membranes, often in an electrogenic manner [PMID: 9261985]. 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 [PMID: 9235899]. 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.

This domain is found at the C terminus of many bicarbonate transport proteins. It is also found in some plant proteins responsible for boron transport [PMID: 12447444]. In these proteins it covers almost the entire length of the sequence.

GO terms

Biological Process

GO:0006820 anion transport

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0016021 integral component of membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
Pfam