SLC9A3
Description
The SLC9A3 (solute carrier family 9 member A3) is a protein-coding gene located on chromosome 5.
SLC9A3, also known as Sodium-hydrogen exchanger 3 (NHE3) or solute carrier family 9 member 3 (SLC9A3), is a protein encoded by the SLC9A3 gene in humans. It acts as a sodium-hydrogen antiporter, primarily responsible for maintaining sodium balance. It is found in various locations, including the apical side of epithelial cells in the proximal tubule of the kidney, the apical membrane of enterocytes in the intestine, and the basolateral side of duodenal and pancreatic cells. NHE3 imports one sodium ion into the cytosol of a tubule cell while ejecting one hydrogen ion into the lumen of the proximal tubule, contributing to sodium retention and indirect blood buffering capacity. Protein kinase C activates NHE3, while protein kinase A inhibits it. A specific regulator, Sodium-hydrogen antiporter 3 regulator 1, also controls its activity. Tenapanor is an inhibitor of NHE3, while insulin acts as a stimulator.
SLC9A3 is a plasma membrane sodium/hydrogen antiporter that exchanges intracellular hydrogen ions for extracellular sodium ions in a 1:1 ratio. This exchange plays a crucial role in salt and fluid absorption and pH homeostasis. SLC9A3 is the major apical sodium/hydrogen exchanger in the kidney and intestine, where it contributes significantly to renal and intestinal sodium absorption and blood pressure regulation.
SLC9A3 is also known as DIAR8, NHE-3, NHE3.
