Large neutral amino acids transporter small subunit 2

Ideogram human chromosome 14

Large Neutral Amino Acids Transporter Small Subunit 2 (LAT2) is a protein that in humans is encoded by the SLC7A8 gene. LAT2 is a member of the solute carrier family and plays a critical role in the transport of large neutral amino acids across the cell membrane. This transporter is particularly important for the reabsorption of amino acids in the kidney and the absorption of amino acids from the diet in the intestine.

Function

LAT2 functions as a component of a heterodimeric amino acid transporter complex along with a heavy chain, typically linked by a disulfide bond to the 4F2hc heavy chain (also known as CD98 or SLC3A2). This complex facilitates the movement of large neutral amino acids, such as leucine, isoleucine, valine, phenylalanine, tyrosine, and tryptophan, across cell membranes. The transport process is sodium-independent but requires the exchange of one amino acid for another, operating on the principle of amino acid antiport.

Clinical Significance

Alterations in the function of LAT2 can lead to various metabolic disorders, including problems with amino acid balance, which can have systemic effects on protein synthesis, neurological function, and metabolic regulation. Given its role in the reabsorption of amino acids in the kidney, mutations affecting LAT2 can contribute to conditions such as Hartnup disease, a disorder characterized by aminoaciduria, or the excessive excretion of amino acids in the urine.

Structure

The LAT2 transporter is encoded by the SLC7A8 gene and is composed of 12 transmembrane domains, which are typical for members of the solute carrier family. The transporter forms a heterodimer with the 4F2hc heavy chain, which is necessary for its proper localization to the plasma membrane and function.

Expression

LAT2 is widely expressed in human tissues, with significant levels found in the kidney, intestine, brain, and placenta. This broad expression pattern reflects the essential role of LAT2 in amino acid transport across different physiological barriers.

Research

Ongoing research is focused on elucidating the detailed mechanisms of LAT2 function, its regulation, and its role in human disease. Studies are also exploring the potential of targeting LAT2 in therapeutic strategies for metabolic disorders and other conditions related to impaired amino acid transport.