Cloning and characterization of the gene encoding the mouse peptide transporter PEPT2

Here we describe the cDNA structure, genomic organization, chromosomal localization, and promoter analysis of the mouse peptide transporter PEPT2. The PEPT2-cDNA is 3987 bp long and encodes a protein of 729 amino acids. The functional properties, analyzed by expression in Xenopus laevis oocytes, showed a typical PEPT2-phenotype with electrogenic, proton-coupled transport, high substrate affinity, and a broad specificity. Immunoblotting of renal brush-border membranes revealed an apparent molecular mass of PEPT2 of 100 kDa. The murine Pept2 gene was cloned from a 129/SvevTACfBr genomic library. It is 34 kb long and comprises 22 exons and 21 introns. By radiation mapping analysis the Pept2 gene was mapped on central mouse chromosome 16. Two putative transcription start sites lying 35 and 235 bp upstream from the translation start were identified. The Pept2 gene possesses a TATA-less promoter. Functional promoter analysis revealed the core promoter to be located between 432 and 286 bp upstream from the translation start.