The solute carrier (SLC) group of membrane transport proteins contains over 400 members classified into 65 families. Most solute carrier proteins are inserted in the cell membrane and are responsible for the transportation of intracellular and extracellular metabolites. Solute carrier family 15 members are proteins encoded by SLC15A genes, and their oligopeptide transporter activity is pH-dependent. With this feature, the members of the SLC15A family are also known as pH-sensing regulatory factors of peptide transporters (PEPTs) . In mammalian cells, four gene members, SLC15A1 (PEPT1), SLC15A2 (PEPT2), SLC15A3 (PHT2), and SLC15A4 (PHT1), comprise the SLC15A family. SLC15A1 and SLC15A2 were first discovered in the small intestine and kidney, and their physiological functions have been well investigated. In addition to taking up peptides, SLC15A3 and SLC15A4 were able to transport histidine across cell membranes with the alias “peptide-histidine transporter. However, these proteins only share less than 20% amino acid homology with SLC15A1 and SLC15A2.
Here you can see a zoomed view of the cholesterol binding site of the human SLC15A4 dimer as determined by cryoEM (PDB code: 8JZS)

#molecularart ... #immolecular ... #membrane ... #cholesterol ... #solute ... #carrier ... #cryoem

Structure rendered with @proteinimaging and represented by @corelphotopaint