Neutral amino acid transporter B(0) is a protein that in humans is encoded by the SLC1A5 gene. Has a broad substrate specificity, a preference for zwitterionic amino acids, and a sodium-dependence. It accepts as substrates all neutral amino acids, including glutamine, asparagine, and branched-chain and aromatic amino acids, and excludes methylated amino acids, anionic amino acids, and cationic amino acids. Acts as a cell surface receptor for feline endogenous virus RD114, baboon M7 endogenous virus and type D simian retroviruses.