Alternative titles; symbols
HGNC Approved Gene Symbol: SLC15A1
Cytogenetic location: 13q32.2-q32.3 Genomic coordinates (GRCh38): 13:98,683,801-98,752,672 (from NCBI)
In mammalian small intestine, the proton-coupled peptide transporter is responsible for the absorption of small peptides arising from digestion of dietary proteins. Fei et al. (1994) isolated a cDNA clone encoding a hydrogen ion/peptide cotransporter from a rabbit intestinal cDNA library. Liang et al. (1995) screened a human intestinal cDNA library with a probe derived from the rabbit cotransporter cDNA and identified a cDNA (SLC15A1) encoding a deduced 708-amino acid protein with 12 membrane-spanning domains and 2 putative sites for protein kinase C-dependent phosphorylation. The human cotransporter showed 81% identity and 92% similarity to the rabbit cotransporter, but only a weak homology to the proton-coupled peptide transport proteins present in bacteria and yeast.
By analysis of somatic cell hybrids and by isotopic in situ hybridization, Liang et al. (1995) mapped the SLC15A1 gene to 13q33-q34.
Liang et al. (1995) found that expression of SLC15A1 in HeLa cells or in Xenopus laevis oocytes induced proton-dependent peptide transport activity. The cDNA-induced transport process accepted dipeptides, tripeptides, and amino beta-lactam antibiotics as substrates, but could not transport free amino acids.
Adibi (1997) reviewed the biology and function of the human intestinal oligopeptide transporter, which he symbolized PEPT1. Studies indicated that it transports dipeptides and tripeptides but not free amino acids or peptides with more than 3 amino acid residues and that its driving force for uphill transport requires proton binding and presence of an inside-negative membrane potential. Adibi (1997) pointed out the importance of the transporter in nutritional and pharmacologic therapies; for example, it has allowed the use of oligopeptides as a source of nitrogen for enteral feeding and the use of the oral route for delivery of peptidomimetic drugs such as beta-lactam antibiotics.
Adibi, S. A. The oligopeptide transporter (Pept-1) in human intestine: biology and function. Gastroenterology 113: 332-340, 1997. [PubMed: 9207295] [Full Text: https://doi.org/10.1016/s0016-5085(97)70112-4]
Fei, Y. -J., Kanai, Y., Nussberger, S., Ganapathy, V., Leibach, F. H., Romero, M. F., Singh, S. K., Boron, W. F., Hediger, M. A. Expression cloning of a mammalian proton-coupled oligopeptide transporter. Nature 368: 563-566, 1994. [PubMed: 8139693] [Full Text: https://doi.org/10.1038/368563a0]
Liang, R., Fei, Y.-J., Prasad, P. D., Ramamoorthy, S., Han, H., Yang-Feng, T. L., Hediger, M. A., Ganapathy, V., Leibach, F. H. Human intestinal H(+)/peptide cotransporter: cloning, functional expression, and chromosomal localization. J. Biol. Chem. 270: 6456-6463, 1995. [PubMed: 7896779] [Full Text: https://doi.org/10.1074/jbc.270.12.6456]