Large neutral amino acids transporter small subunit 1

SLC7A5 (LAT1) encodes the large neutral amino acid transporter small subunit 1, a component of a heterodimer with SLC3A2 that mediates sodium-independent, high-affinity uptake of large neutral amino acids including phenylalanine, tyrosine, leucine, and tryptophan (UniProt: Q01650). The transporter also facilitates L-DOPA uptake across the blood-brain barrier and can transport thyroid hormones and other substrates. When associated with LAPTM4B, the SLC3A2/SLC7A5 complex is recruited to lysosomes to promote leucine-dependent mTORC1 activation.

SLC7A5 is broadly expressed and plays roles in amino acid homeostasis across multiple tissues. The UniProt record contains no annotated disease associations in baseline curated data (UniProt: Q01650).

In Alzheimer's disease, SLC7A5 shows significant upregulation in post-mortem AD brain tissue compared to age-matched controls, with a mean log2 fold-change of 1.12 across subcellular fractions (Chaparral AD proteomics). This elevation suggests increased large neutral amino acid transport capacity in the AD brain, potentially reflecting altered metabolic demands or compensatory responses associated with neurodegeneration.