Mediates sodium-dependent transport of amino acids. Substrate preference is ranked l-glutamine > l-histidine > l-serine > l-alanine > l-asparagine > l-aspartic acid > l-glutamic acid > l-methionine > l-leucine > l-glycine. In neurons, located in soma and axons. Highly expressed in the brain, including the hippocampus, especially in the granular layer of dentate gyrus cells and the pyramidal cell layer of the hippocampus, amygdala, thalamus, hypothalamus, in the layer of Purkinje cells in the cerebellum and the layers of cortex. Particularly strong expression in neurons of the ventromedial hypothalamus, basolateral amygdala, ventral tegmental area, and locus coeruleus. Not detected in glial cells, including astrocytes. In addition to brain, also expressed in the spinal cord (at protein level). Belongs to the amino acid/polyamine transporter 2 family.