Solute carrier family 22 (organic cation transporter), member 1, also called SLC22A1 or OCT1 is a protein that in humans is encoded by the SLC22A1 gene. This gene is mapped to 6q25.3. Polyspecific organic cation transporters in the liver, kidney, intestine, and other organs are critical for elimination of many endogenous small organic cations as well as a wide array of drugs and environmental toxins. This gene transports the polyamines spermine and spermidine. It also transports pramipexole across the basolateral membrane of the proximal tubular epithelial cells. This gene regulated by various intracellular signaling pathways including inhibition by protein kinase A activation, and endogenously activation by the calmodulin complex, the calmodulin-dependent kinase II and LCK tyrosine kinase.