Solute carrier family 7 member 5 also known as large neutral amino acids transporter small subunit 1 is a protein that in humans is encoded by the SLC7A5 gene.It is sodium-independent, high-affinity transport of large neutral amino acids such as phenylalanine, tyrosine, leucine, arginine and tryptophan, when associated with SLC3A2/4F2hc.It involved in cellular amino acid uptake and the transport of L-DOPA across the blood-brain barrier, and that of thyroid hormones triiodothyronine (T3) and thyroxine (T4) across the cell membrane in tissues such as placenta.Acts as an amino acid exchanger and plays a role in neuronal cell proliferation (neurogenesis) in brain.