This gene encodes a Na+/H+ antiporter that is a member of the solute carrier family 9. The encoded protein is a plasma membrane transporter that is expressed in the kidney and intestine. This protein plays a central role in regulating pH homeostasis, cell migration and cell volume. This protein may also be involved in tumor growth. [From RefSeq]

The SLC9A1 gene is located on the short arm of chromosome 1. The gene consists of 12 exons and spans a length of about 68 Kb. The NHE1 protein is made of 815 amino acid residues and has a size of about 90 kDa. It is anchored to the plasma membrane by actin filaments. NHE1 activity is stimulated by several growth hormones and mitogens, including EGF and insulin. These activators have been shown to carry out phosphorylation of the protein by kinases as well as dephosphorylation by protein phosphatases. These changes in the phosphorylation status are expected to modulate the activity of the antiporter, most likely through changes in the interaction between the C-terminal cytoplasmic domain of the protein and the actin cytoskeleton.