Together with the SLC26 family, the SLC4 family of transporters subserve anion exchange, principally of chloride and bicarbonate (HCO₃^-), but also carbonate and hydrogen sulphate (HSO₄^-). SLC4 family members regulate bicarbonate fluxes as part of carbon dioxide movement, chyme neutralization and reabsorption in the kidney.

Within the family, subgroups of transporters are identifiable: the electroneutral sodium-independent Cl^-/HCO₃^- transporters (AE1, AE2 and AE3), the electrogenic sodium-dependent HCO₃^- transporters (NBCe1 and NBCe2) and the electroneutral HCO₃^- transporters (NBCn1 and NBCn2). Topographical information derives mainly from study of AE1, abundant in erythrocytes, which suggests a dimeric or tetrameric arrangement, with subunits made up of 13 TM domains and re-entrant loops at TM9/10 and TM11/12. The N terminus exhibits sites for interaction with multiple proteins, including glycolytic enzymes, haemoglobin and cytoskeletal elements.

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* Key recommended reading is highlighted with an asterisk

Alper SL. (2009) Molecular physiology and genetics of Na+-independent SLC4 anion exchangers. J Exp Biol, 212 (Pt 11): 1672-83. [PMID:19448077]

Boron WF, Chen L, Parker MD. (2009) Modular structure of sodium-coupled bicarbonate transporters. J Exp Biol, 212 (Pt 11): 1697-706. [PMID:19448079]

Christensen HL, Nguyen AT, Pedersen FD, Damkier HH. (2013) Na(+) dependent acid-base transporters in the choroid plexus; insights from slc4 and slc9 gene deletion studies. Front Physiol, 4: 304. [PMID:24155723]

Kurtz I. (2014) NBCe1 as a model carrier for understanding the structure-function properties of Na⁺ -coupled SLC4 transporters in health and disease. Pflugers Arch, 466 (8): 1501-16. [PMID:24515290]

Liu Y, Wang DK, Chen LM. (2012) The physiology of bicarbonate transporters in mammalian reproduction. Biol Reprod, 86 (4): 99. [PMID:22262691]

* Majumdar D, Bevensee MO. (2010) Na-coupled bicarbonate transporters of the solute carrier 4 family in the nervous system: function, localization, and relevance to neurologic function. Neuroscience, 171 (4): 951-72. [PMID:20884330]

* Parker MD, Boron WF. (2013) The divergence, actions, roles, and relatives of sodium-coupled bicarbonate transporters. Physiol Rev, 93 (2): 803-959. [PMID:23589833]

* Reithmeier RA, Casey JR, Kalli AC, Sansom MS, Alguel Y, Iwata S. (2016) Band 3, the human red cell chloride/bicarbonate anion exchanger (AE1, SLC4A1), in a structural context. Biochim Biophys Acta, 1858 (7 Pt A): 1507-32. [PMID:27058983]

* Romero MF, Chen AP, Parker MD, Boron WF. (2013) The SLC4 family of bicarbonate (HCO₃⁻) transporters. Mol Aspects Med, 34 (2-3): 159-82. [PMID:23506864]

Romero MF, Fulton CM, Boron WF. (2004) The SLC4 family of HCO 3 - transporters. Pflugers Arch, 447 (5): 495-509. [PMID:14722772]

Ruffin VA, Salameh AI, Boron WF, Parker MD. (2014) Intracellular pH regulation by acid-base transporters in mammalian neurons. Front Physiol, 5: 43. [PMID:24592239]

* Thornell IM, Bevensee MO. (2015) Regulators of Slc4 bicarbonate transporter activity. Front Physiol, 6: 166. [PMID:26124722]