The function of SLC38A2 (solute carrier family 38 member 2, ENSG00000134294) is as follows. Symporter that cotransports neutral amino acids and sodium ions from the extracellular to the intracellular side of the cell membrane (PubMed:10930503, PubMed:15774260, PubMed:15922329, PubMed:16621798). The transport is pH-sensitive, Li(+)-intolerant, electrogenic, driven by the Na(+) electrochemical gradient and cotransports of neutral amino acids and sodium ions with a stoichiometry of 1:1. May function in the transport of amino acids at the blood-brain barrier (PubMed:10930503, PubMed:15774260). May function in the transport of amino acids in the supply of maternal nutrients to the fetus through the placenta (By similarity). Maintains a key metabolic glutamine/glutamate balance underpinning retrograde signaling by dendritic release of the neurotransmitter glutamate (By similarity). Transports L-proline in differentiating osteoblasts for the efficient synthesis of proline-enriched proteins and provides proline essential for osteoblast differentiation and bone formation during bone development (By similarity). {ECO:0000250|UniProtKB:Q8CFE6, ECO:0000250|UniProtKB:Q9JHE5, ECO:0000269|PubMed:10930503, ECO:0000269|PubMed:15774260, ECO:0000269|PubMed:15922329, ECO:0000269|PubMed:16621798}.