SLC7A5
Description
The SLC7A5 (solute carrier family 7 member 5) is a protein-coding gene located on chromosome 16.
Large neutral amino acids transporter small subunit 1, also known as 4F2 light chain, or CD98 light chain is a protein that in humans is encoded by the SLC7A5 gene.
The heterodimer of SLC7A5 with SLC3A2 acts as a sodium-independent, high-affinity transporter responsible for the uptake of large neutral amino acids like phenylalanine, tyrosine, leucine, histidine, methionine, tryptophan, valine, isoleucine, and alanine. It also mediates the uptake of L-DOPA and functions as an amino acid exchanger. This heterodimer may play a role in L-DOPA transport across the blood-brain barrier, act as the primary transporter for tyrosine in fibroblasts, and mediate L-leucine transport across the inner blood-retinal barrier. It can also transport thyroid hormones like diiodothyronine (T2), triiodothyronine (T3), and thyroxine (T4) across the cell membrane. When associated with LAPTM4B, the heterodimer is recruited to lysosomes, facilitating leucine uptake and subsequently activating mTORC1. This transporter is involved in the uptake of toxic methylmercury (MeHg) when administered as L-cysteine or D,L-homocysteine complexes and plays a role in the cellular activity of small molecular weight nitrosothiols by transporting L-nitrosocysteine (L-CNSO) across the membrane. In cases of hepatitis C virus (HCV) infection, the SLC3A2-SLC7A5/LAT1 complex facilitates viral entry into host cells and increases L-leucine uptake, activating mTORC1 signaling and contributing to HCV pathogenesis. SLC7A5 forms a disulfide-linked heterodimer with the amino acid transport protein SLC3A2/4F2hc. It interacts with LAPTM4B, which recruits the SLC3A2/4F2hc-SLC7A5 heterodimer to lysosomes, promoting leucine uptake into these organelles and activating mTORC1.
SLC7A5 is also known as 4F2LC, CD98, D16S469E, E16, LAT1, MPE16.
