Send to

Choose Destination
Biochem J. 2005 Aug 1;389(Pt 3):745-51.

Characterization of mouse amino acid transporter B0AT1 (slc6a19).

Author information

Physiologisches Institut, Universität Tübingen, 72076 Tübingen, Germany.


The mechanism of the mouse (m)B0AT1 (slc6a19) transporter was studied in detail using two electrode voltage-clamp techniques and tracer studies in the Xenopus oocyte expression system. All neutral amino acids induced inward currents at physiological potentials, but large neutral non-aromatic amino acids were the preferred substrates of mB0AT1. Substrates were transported with K0.5 values ranging from approx. 1 mM to approx. 10 mM. The transporter mediates Na+-amino acid co-transport with a stoichiometry of 1:1. No other ions were involved in the transport mechanism. An increase in the extracellular Na+ concentration reduced the K0.5 for leucine, and vice versa. Moreover, the K0.5 values and Vmax values of both substrates varied with the membrane potential. As a result, K0.5 and Vmax values are a complex function of the concentration of substrate and co-substrate and the membrane potential. A model is presented assuming random binding order and a positive charge associated with the ternary [Na+-substrate-transporter] complex, which is consistent with the experimental data.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Silverchair Information Systems Icon for PubMed Central
Loading ...
Support Center