High impact information on SLC6A19

• SLC6A19 is a sodium-dependent and chloride-independent neutral amino acid transporter, expressed predominately in kidney and intestine, with properties of system B(0) [1].
• We identified six mutations in SLC6A19 that cosegregated with disease in the predicted recessive manner, with most affected individuals being compound heterozygotes [1].
• We localized a gene causing Hartnup disorder to chromosome 5p15.33 and cloned a new gene, SLC6A19, in this region [1].
• An important player is the newly identified cotransporter (symporter) B0AT1 (SLC6A19), which imports a broad range of neutral amino acids together with Na+ across the luminal membrane and which is defective in Hartnup disorder [2].
• Furthermore, in the kidney, collectrin-deficient mice have decreased plasma membrane populations of amino acid transporter subtypes B(0)AT1, rBAT, and b(0,+)AT, as well as altered cellular distribution of EAAC1 [3].

Anatomical context of SLC6A19

• RT-PCR revealed that Caco-2 cells expressed the Na(+)-dependent neutral amino acid transporter ASCT2, but not the other Na(+)-dependent neutral amino acid transporters ATB(0,+) and B(0)AT1 [4].
• For example, the expression levels of B(0)AT1, a Na+-dependent and chloride-independent neutral amino acid transporter, were increased from the duodenum to ileum, which pattern is completely inverted to that for PEPT1 [5].
• In conclusion, PEPT1 was abundantly expressed in the small intestine, and the reciprocal expression of PEPT1 and B(0)AT1 may serve for the efficient absorption of protein digestive products [5].
• Expression of collectrin in Xenopus oocytes and Madin-Darby canine kidney (MDCK) cells enhances amino acid transport by the transporter B(0)AT1 [6].

References