The Slc22 family of organic anion and cation transporters (OATs, OCTs, OCTNs) are transmembrane proteins expressed predominantly in kidney and liver. Each contain 12 predicted alpha-helical transmembrane domains (TMDs) and one large extracellular loop between TMDs 1 and 2. Transporters of the SLC22 family function in different ways such as uniporters that mediate facilitated diffusion in either direction (OCTs), as anion exchangers (OAT1, OAT3 and URAT1), and as Na(+)/l-carnitine cotransporter (OCTN2). Slc22 family members participate in the absorption and/or excretion of drugs, xenobiotics, and endogenous compounds in intestine, liver, and kidney, and perform homeostatic functions in brain and heart. Mutations in the Slc22 family may cause specific diseases such as primary systemic carnitine deficiency or idiopathic renal hypouricemia and may change drug absorption or excretion. Recent studies show the expression of Slc22A17 as receptor for Lipocalin 2 is relatively high in hematopoietic stem cells.
24p3 receptor; 24p3R; Brain-type organic cation transporter; Lipocalin-2 receptor; Neutrophil gelatinase-associated lipocalin receptor; NGAL receptor; NgalR; potent brain type organic ion transporter; solute carrier family 22 (organic cation transporter), member 17; Solute carrier family 22 member 17; solute carrier family 22, member 17