Solute Carrier Family 22, Member 21 (SLC22A21)

SLC22A21, Belongs to the major facilitator superfamily. Organic cation transporter family. Predominantly expressed in testis.Sodium-ion independent, medium affinity carnitine transporter. Also transports organic cations such as tetraethylammonium (TEA) without the involvement of sodium. Organic cations include endogenous compounds such as monoamine neurotransmitters, choline, and coenzymes, but also numerous drugs and xenobiotics. Some of the cloned organic cation transporters accept one main substrate or structurally similar compounds, while others translocate a variety of structurally diverse organic cations. The polyspecific cation transporters of the SLC22 family including the subtypes OCT1-3 and OCTN1-2 are presented in detail, covering the current knowledge about distribution, substrate specificity, and recent data on their electrical properties and regulation.