Electrogenic sodium bicarbonate cotransporter 1

Electrogenic sodium bicarbonate cotransporter 1 (also known as NBCe1) is a protein that in humans is encoded by the SLC4A4 gene. This protein is a member of the solute carrier family and is predominantly expressed in the kidney and pancreas.

Function

NBCe1 is an electrogenic transporter that moves sodium and bicarbonate ions across the cell membrane. This process is essential for the regulation of pH in the body and the reabsorption of bicarbonate in the kidneys. Mutations in the SLC4A4 gene can lead to various medical conditions, including renal tubular acidosis and glaucoma.

Structure

The NBCe1 protein is composed of 14 transmembrane domains with both the N- and C-termini located intracellularly. The protein also contains a large intracellular loop between transmembrane domains 7 and 8, which is thought to be involved in the regulation of transporter activity.

Clinical significance

Mutations in the SLC4A4 gene that encodes NBCe1 can cause proximal renal tubular acidosis, a condition characterized by the kidney's inability to properly reabsorb bicarbonate. This can lead to metabolic acidosis, a condition where the body's fluids contain too much acid. Additionally, mutations in this gene have been associated with ocular defects such as glaucoma and cataracts.

See also

• Solute carrier family
• Renal tubular acidosis
• Glaucoma