2.A.1.19.8
The human organic cation transporter, SLC22A17.  The rat orthologue may be inactive (Bennett et al. 2011). It is also the cell surface receptor for Lipocalin-2 (LCN2) that plays a key role in iron homeostasis and transport. It is able to bind iron-LCN2, followed by internalization and release of iron, thereby increasing intracellular iron concentration and leading to inhibition of apoptosis (Cabedo Martinez et al. 2016). It also binds iron-free LCN2, followed by internalization and its association with an intracellular siderophore, leading to iron chelation and iron transfer to the extracellular medium, thereby reducing intracellular iron concentrations and resulting in apoptosis.  The SLC22A17/lipocalin-2 receptor plays a role in renal endocytosis of proteins involved in metalloproteins, particularly on iron- and cadmium-binding proteins (Thévenod et al. 2023).  Other renal functions of SLC22A17 include its contribution to osmotic stress adaptation, protection against urinary tract infection, and renal carcinogenesis.