LAT1
LAT1 is a heterodimeric membrane transport protein that preferentially transports branched-chain (valine, leucine, isoleucine) and aromatic (tryptophan, tyrosine) amino acids.
LAT is highly expressed in brain capillaries (which form the blood–brain barrier) relative to other tissues.
A functional LAT1 transporter is composed of two proteins encoded by two distinct genes:
4F2hc/CD98 heavy subunit protein encoded by the SLC3A2 gene. CD98 light subunit protein encoded by the SLC7A5 gene.
The overexpression of LAT1 transports in brain metastases make intracranial metastases a compelling target for amino acid PET imaging 1).
1)
Papin-Michault C, Bonnetaud C, Dufour M, et al. Study of LAT1 Expression in Brain
Metastases: Towards a Better Understanding of the Results of Positron Emission
Tomography Using Amino Acid Tracers. PloS one. 2016; 11(6):e0157139.