Cloning and genomic organization of the mouse gene Slc23a1 encoding a vitamin C transporter

Vitamin C is known to exist in particularly high concentrations in brain ti ssue, and its free radical scavenging function is thought to represent a ma jor antioxidative defense system. We have cloned, sequenced and analyzed th e genomic structure of a mouse sodium-dependent vitamin C transporter gene, Slc23a1 (also known as Svct2). The mouse Slc23a1 cDNA is 6.4 kb long and w as cloned directly from a mouse brain RNA preparation. Hybridization screen ing of a mouse genomic BAC library identified BAC 53L21 which contains at l east the entire coding sequence of the mouse Slc23a1 gene. Determination of the exon-intron structure of the gene revealed 17 exons ranging from 58 bp to 4407 bp extending over 50 kb of the mouse genome, with the translation start codon located in exon 3. Its 1944 nucleotide open reading frame encod es a polypeptide of 647 aa, which is highly similar to rat and human orthol ogs. The mouse gene was assigned to chromosome 2qG2 by fluorescence in situ hybridization analysis. Expression of this gene was demonstrated in a wide range of tissues, with especially high levels in brain. Neurodegenerative diseases with an established role for oxidative stress in the cytoplasm may therefore be conditions of SLC23A1 dysfunction.