Reactome: A Curated Pathway Database

SLC4A5,7,9 cotransport Na+ with 3HCO3-

Stable Identifier
Homo sapiens
Locations in the PathwayBrowser

Members of the SLC4A family couple the transport of bicarbonate (HCO3-) with sodium ions (Na+); they being members 4, 5, 7 and 9. SLC4A5 encodes a protein which is expressed in liver, spleen and testes, with lower levels expressed in parts of the brain and kidney (Sassani et al. 2002). It may have a housekeeping function in regulating the pH of these tissues (Pushkin et al. 2000).

SLC4A7 (aka NBC3, NBCn1) encodes a protein which performs electroneutral cotransport of Na+ and HCO3- with a 1:1 stoichiometry. It is highly expressed in testes and spleen and, to a lesser extent, in many other tissues including heart, muscle, kidney and GI tract (Pushkin et al. 1999).

SLC4A9 (aka AE4) was originally thought to exchange Cl- with HCO3- (hence the name AE4) but this has not been reported. Consensus has emerged that it is indeed a Na+/HCO3- co-transporter (Lipovich et al. 2001). It is predominantly expressed in the kidney, salivary glands, testes, thyroid glands and trachea (Parker et al. 2001).

Literature References
Participant Of
This entity is regulated by:
Title Physical Entity Activity
sodium:bicarbonate symporter activity of SLC4A5,7,9 [plasma membrane] SLC4A5,7,9 [plasma membrane] sodium:bicarbonate symporter activity (0008510)
Orthologous Events