LAT-1 (L-type amino acid transporter 1) is a system L, Na(+)-independent amino acid transporter responsible for transport of large neutral amino acids. Dysregulated expression of LAT-1 is characteristic of many primary human cancers and is related to tumor invasion. Primary rat hepatocytes in culture increase LAT-1 mRNA in response to amino acid depletion. Transformed hepatic cell lines demonstrate constitutive expression of LAT-1. These observations suggest that LAT-1 expression confers a growth and survival advantage under limited amino acid availability. LAT-1 is highly expressed in the placenta. It has been shown previously that amino acids are fundamental regulators of cell function and energy metabolism in pre-implantation embryos. Our objectives were to analyze qualitatively and quantitatively LAT-1 expression in pre-implantation stages of mouse embryo development and to identify cell types expressing LAT-1 in post-implantation stages.
Division of Biology and Medicine, Graduate Program in Pathobiology, Brown University, Providence, Rhode Island, Brown University, 101 Dudley St, Providence, RI 02905, USA.
