Definition:

Associates with SLC3A2/4F2hc to form a functional heterodimeric complex that translocates small neutral L- and D-amino acids across the plasma membrane. Preferentially mediates exchange transport, but can also operate via facilitated diffusion (By similarity). Acts as a major transporter for glycine, L- and D-serine in the central nervous system. At the spinal cord and brainstem regulates glycine metabolism and glycinergic inhibitory neurotransmission by providing for glycine de novo synthesis from L-serine and glycine recycling from astrocytes to glycinergic motor neurons (By similarity). At Schaffer collateral-CA1 synapses mediates D-serine and glycine release that modulates post-synaptic activation of NMDA receptors and excitatory glutamatergic transmission (By similarity). May regulate D-serine release from mesenchymal progenitors located in developing subcutaneous adipose tissue, favoring white adipocyte over thermogenic beige adipocyte lineage commitment (By similarity).