Reaction: SLC9B2 exchanges Na+ for H+
- in pathway: Stimuli-sensing channels
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).
Reaction - small molecule participants:
Na+ [mitochondrial matrix]
H+ [mitochondrial intermembrane space]
Na+ [mitochondrial intermembrane space]
H+ [mitochondrial matrix]
Reactome.org reaction link: R-HSA-2889070
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Reaction input - small molecules:
sodium(1+)
hydron
Reaction output - small molecules:
sodium(1+)
hydron
Reactome.org link: R-HSA-2889070