Proton-coupled amino acid transporter 1

Proton-coupled amino acid transporter 1 (PAT1), also known as SLC36A1, is a protein that in humans is encoded by the SLC36A1 gene. This protein is a member of the solute carrier family 36 (proton/amino acid symporter), member 1. This transporter is a major route for the uptake of proteinogenic amino acids, particularly neutral and cationic amino acids.

Function

The proton-coupled amino acid transporter 1 (PAT1) is a membrane transport protein that facilitates the cellular uptake of amino acids in a manner that is coupled to proton transport. This transporter is responsible for the absorption of dietary amino acids in the intestine and the reabsorption of amino acids in the kidney. It is also involved in the transport of amino acids across the blood-brain barrier.

Structure

The SLC36A1 gene encodes a protein of 506 amino acids with 11 predicted transmembrane domains. The protein has a large extracellular loop between the third and fourth transmembrane domains, and a large intracellular loop between the sixth and seventh transmembrane domains. The N-terminus of the protein is predicted to be extracellular, while the C-terminus is predicted to be intracellular.

Clinical significance

Mutations in the SLC36A1 gene have been associated with a rare inherited disorder called iminoglycinuria, which is characterized by excessive excretion of the amino acids proline, hydroxyproline, and glycine in the urine. This condition is generally benign and does not cause any symptoms, but it can be detected by routine urine tests.

See also

• Solute carrier family
• Amino acid transporter
• Proton-coupled amino acid transporter