Large neutral amino acid transporter 1 (LAT1) (LAT1)

Large neutral amino acid transporter 1 (LAT1), encoded by the SLC7A5 gene, is a sodium-independent transporter that functions as an obligatory exchanger for essential large neutral amino acids (UniProt P48023). It is the primary molecular entity responsible for the intestinal absorption of Levodopa (L-DOPA) and its subsequent transport across the blood-brain barrier into the central nervous system (StatPearls, NBK482412). Because LAT1 is an exchanger, its transport efficiency is highly dependent on the concentration gradients of its substrates, making L-DOPA absorption susceptible to competitive inhibition by dietary proteins (PubMed, PMID: 25851197). This competition is a major factor in the 'on-off' fluctuations observed in Parkinson's disease patients. Beyond its role in drug delivery, LAT1 is frequently overexpressed in various malignancies to support the metabolic demands of rapid cell growth, making it a significant target for cancer therapeutics and diagnostic imaging (PubMed, PMID: 30114414). Consequently, LAT1 represents both a critical pharmacokinetic hurdle for neurological drugs and a promising therapeutic target in oncology.

Other names

SLC7A5Solute carrier family 7 member 5L-type amino acid transporter 1CD98 light chainCD98LC

Acts as a substrate for facilitated transport across the intestinal epithelium and blood-brain barrier; can be inhibited by competitive antagonists to reduce tumor growth.