SLC3A2 is a member of the solute carrier family and encodes a cell surface, transmembrane protein with an alpha-amylase domain. The protein exists as the heavy chain of a heterodimer, covalently bound through di-sulfide bonds to one of several possible light chains. It associates with integrins and mediates integrin-dependent signaling related to normal cell growth and tumorigenesis. Alternate transcriptional splice variants, encoding different isoforms, have been characterized.[6]
LAT1 is a heterodimeric membrane transport protein that preferentially transports neutral branched (valine, leucine, isoleucine) and aromatic (tryptophan, tyrosine, phenylalanine) amino acids.[9] LAT is highly expressed in brain capillaries (which form the blood brain barrier) relative to other tissues.[9]
A functional LAT1 transporter is composed of two proteins encoded by two distinct genes:
- 4F2hc/CD98 heavy subunit protein encoded by the SLC3A2 gene (this gene)[10]
- CD98 light subunit protein encoded by the SLC7A5 gene[11]
