SLC9B2 exchanges Na+ for H+

Stable Identifier
Reaction [transition]
Homo sapiens
H(+)(in) + Na(+)(out) => H(+)(out) + Na(+)(in)
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The widely expressed mitochondrial sodium/hydrogen exchanger 9B2 (SLC9B2, aka NHA2) mediates the exchange of Na+ for H+ across the inner mitochondrial membrane. (SLC9B2 also mediates Li+/H+ exchange, annotated as a separate reaction.) This transport is thought to play a role in salt homeostasis and pH regulation in humans (Fuster et al. 2008; Xiang et al. 2007).

The close similarity between SLC9B2 protein and NhaA, its E. coli ortholog, which mediates electrogenic transport of these ions (Taglicht et al. 1993), suggested that SLC9B2 transport might likewise be electrogenic (Xiang et al. 2007). Later work, however, indicates that SLC9B2 mediates the exchange of a single metal ion for a single proton (Uzdavinys et al. 2017).

Mass spectroscopic studies suggest that SLC9B2 exists as a homodimer (Landreh et al. 2017).

Literature References
PubMed ID Title Journal Year
28154142 Dissecting the proton transport pathway in electrogenic Na+/H+ antiporters

Winkelmann, I, Ndi, M, Nji, E, von Ballmoos, C, Drew, D, Coinçon, M, Uzdavinys, P

Proc Natl Acad Sci U S A 2017
28071645 Integrating mass spectrometry with MD simulations reveals the role of lipids in Na+/H+ antiporters

Landreh, M, Gupta, K, Benesch, JL, Degiacomi, MT, Liko, I, Robinson, CV, Marklund, EG, Drew, D, Gault, J, Coinçon, M, Uzdavinys, P

Nat Commun 2017
8383669 Proton-sodium stoichiometry of NhaA, an electrogenic antiporter from Escherichia coli

Padan, E, Taglicht, D, Schuldiner, S

J. Biol. Chem. 1993
18000046 A human Na+/H+ antiporter sharing evolutionary origins with bacterial NhaA may be a candidate gene for essential hypertension

Muend, S, Xiang, M, Rao, R, Feng, M

Proc. Natl. Acad. Sci. U.S.A. 2007
18508966 Characterization of the sodium/hydrogen exchanger NHA2

Andersson, S, Bobulescu, IA, Fuster, DG, Shi, M, Zhang, J, Moe, OW

J Am Soc Nephrol 2008
Catalyst Activity

sodium:proton antiporter activity of SLC9B2 dimer [mitochondrial inner membrane]

Orthologous Events
Cross References
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