Amino acid transporter heavy chain SLC3A2

SLC3A2 (amino acid transporter heavy chain) is a 57.9 kDa protein that acts as a molecular chaperone facilitating the biogenesis and trafficking of functional amino acid transporter heterodimers to the plasma membrane (UniProt: P08195). It forms essential complexes with SLC7 family members including SLC7A5, SLC7A8, SLC7A11, and others, enabling diverse transport functions ranging from neutral and dibasic amino acid exchange to cystine/glutamate antiport. SLC3A2 is critical for plasma membrane localization and stability of these heterodimeric transporters.

In normal physiology, SLC3A2-containing complexes regulate amino acid homeostasis and facilitate mTORC1 signaling via leucine uptake into lysosomes. The protein also modulates integrin-dependent cellular migration and spreading. Beyond amino acid transport, SLC3A2 serves roles in viral propagation (hepatitis C) and as a receptor for the malaria parasite Plasmodium vivax in immature red blood cells (UniProt: P08195).

SLC3A2 is upregulated in Alzheimer's disease brain tissue relative to age-matched controls, with a mean log2 fold-change of +1.09 across post-mortem human AD brain fractions analyzed by mass spectrometry (Chaparral AD proteomics). This upregulation suggests altered amino acid metabolism or mTORC1 signaling may be associated with AD pathology, though mechanistic links remain to be established.