Transporter that mediates resorption of neutral amino acids across the apical membrane of renal and intestinal epithelial cells. This uptake is sodium-dependent and chloride-independent. Requires CLTRN in kidney or ACE2 in intestine for cell surface expression and amino acid transporter activity. L-alanine(in) + Na(+)(in) = L-alanine(out) + Na(+)(out) L-cysteine(in) + Na(+)(in) = L-cysteine(out) + Na(+)(out) L-glutamine(in) + Na(+)(in) = L-glutamine(out) + Na(+)(out) glycine(in) + Na(+)(in) = glycine(out) + Na(+)(out) L-isoleucine(in) + Na(+)(in) = L-isoleucine(out) + Na(+)(out) L-leucine(in) + Na(+)(in) = L-leucine(out) + Na(+)(out) L-methionine(in) + Na(+)(in) = L-methionine(out) + Na(+)(out) L-phenylalanine(in) + Na(+)(in) = L-phenylalanine(out) + Na(+)(out) L-serine(in) + Na(+)(in) = L-serine(out) + Na(+)(out) L-tryptophan(in) + Na(+)(in) = L-tryptophan(out) + Na(+)(out) L-tyrosine(in) + Na(+)(in) = L-tyrosine(out) + Na(+)(out) L-valine(in) + Na(+)(in) = L-valine(out) + Na(+)(out) Interacts in a tissue-specific manner with ACE2 in small intestine and with CLTRN in the kidney. Interacts with CLTRN; this interaction is required for trafficking of SLC6A19 to the plasma membrane and for its catalytic activation in kidneys. Interacts with ACE2; this interaction is required for trafficking of SLC6A19 to the plasma membrane and for its catalytic activation in intestine. Interacts with ANPEP; the interaction positively regulates its amino acid transporter activity (By similarity). By high salt intake in SHR rats. Reduced level upon high salt intake in Wistar Kyoto rats. Belongs to the sodium:neurotransmitter symporter (SNF) (TC 2.A.22) family. SLC6A19 subfamily.