Role of the System L permease LAT1 in amino acid and iodothyronine transport in placenta.

Article Details

Citation

Ritchie JW, Taylor PM

Role of the System L permease LAT1 in amino acid and iodothyronine transport in placenta.

Biochem J. 2001 Jun 15;356(Pt 3):719-25.

PubMed ID
11389679 [ View in PubMed
]
Abstract

The feto-placental unit relies on a maternal supply of indispensable amino acids and iodothyronines for early development and normal growth. We examined the role of the System L transporter in placental uptake of these substances, using the human placental choriocarcinoma cell line BeWo as a model experimental system. BeWo cells express both heavy (4F2hc) and light (LAT1, LAT2) chains of the System L holotransporter. Saturable transport of both L-[(3)H]tryptophan and [(125)I]tri-iodo-L-thyronine in BeWo cells includes components sensitive to inhibition by the System-L-specific substrate 2-endoamino-bicycloheptane-2-carboxylic acid; kinetic properties of these components indicate that the 4F2hc-LAT1 transporter isoform is likely to predominate for the carriage of both substances at physiologically relevant concentrations. Both 4F2hc and LAT1 proteins are also expressed in human placental membranes and LAT1 at least is localized largely to the syncytiotrophoblast layer of the term human placenta. The 4F2hc-LAT1 transporter might therefore serve a vital role in supplying the developing fetus and the placenta with both thyroid hormones and indispensable amino acids from the maternal circulation.

DrugBank Data that Cites this Article

Polypeptides
NameUniProt ID
Large neutral amino acids transporter small subunit 1Q01650Details