SLC6A15 shows structural characteristics of an Na(+) and Cl(-)-dependent neurotransmitter transporter, including 12 transmembrane (TM) domains, intracellular N and C termini, and large extracellular loops containing multiple N-glycosylation sites (Farmer et al., 2000 [PubMed 11112352]).[supplied by OMIM, Mar 2008].
Function: Functions as a sodium-dependent neutral amino acid transporter. Exhibits preference for the branched-chain amino acids, particulary leucine, valine and isoleucine and methionine. Mediates the saturable, pH-sensitive and electrogenic cotransport of proline and sodium ions with a stoichiometry of 1:1. May have a role as transporter for neurotransmitter precursors into neurons. In contrast to other members of the neurotransmitter transporter family, does not appear to be chloride-dependent.