Sodium–hydrogen antiporter
The sodium–hydrogen antiporter or sodium–proton exchanger (Na+/H+ exchanger or NHX) is a membrane protein that transports Na+ into the cell, and H+ out of the cell (antiport). The pump is located in the intercalated cells of the collecting duct and in the epithelial cells of the proximal convoluted tubule.
Source: Wikipedia — Sodium–hydrogen antiporter (CC BY-SA 4.0)