SLC22A1
Description
The SLC22A1 (solute carrier family 22 member 1) is a protein-coding gene located on chromosome 6.
Solute carrier family 22 member 1 (SLC22A1) is a protein that in humans is encoded by the gene SLC22A1. It is one of three similar cation transporter genes located on chromosome 6. The encoded protein contains twelve putative transmembrane domains and is a plasma integral membrane protein. Two transcript variants encoding two different isoforms have been found for this gene, but only the longer variant encodes a functional transporter. SLC22A1 is involved in the elimination of many endogenous small organic cations, as well as a wide array of drugs and environmental toxins. It is also required for the uptake of metformin by cells.
SLC22A1, also known as Organic cation transporter 1, is an electrogenic voltage-dependent transporter that mediates the transport of a variety of organic cations, including endogenous bioactive amines, cationic drugs and xenobiotics. It acts as a pH- and Na(+)-independent, bidirectional transporter. The transport of cations is driven by the electrochemical potential, which includes membrane potential and concentration gradient, as well as substrate selectivity. Hydrophobicity is a major requirement for recognition in polyvalent substrates and inhibitors. SLC22A1 is mainly expressed at the basolateral membrane of hepatocytes and proximal tubules. It plays a role in the uptake and disposition of cationic compounds through hepatic and renal clearance from the blood flow. SLC22A1 also functions as an uptake carrier in enterocytes, contributing to the intestinal elimination of organic cations from the systemic circulation. It transports endogenous monoamines such as N-1-methylnicotinamide (NMN), guanidine, histamine, neurotransmitters dopamine, serotonin, and adrenaline. It also transports natural polyamines such as spermidine, agmatine, and putrescine at low affinity but with relatively high turnover. SLC22A1 is involved in the hepatic uptake of vitamin B1/thiamine, which regulates hepatic lipid and energy metabolism. It mediates the bidirectional transport of acetylcholine (ACh) at the apical membrane of ciliated cells in airway epithelium, playing a role in the luminal release of ACh from bronchial epithelium. SLC22A1 transports dopaminergic neuromodulators cyclo(his-pro) and salsolinol with lower efficiency. It can also transport non-amine endogenous compounds such as prostaglandin E2 (PGE2) and prostaglandin F2-alpha (PGF2-alpha). It may contribute to the transport of cationic compounds in testes across the blood-testis barrier. SLC22A1 is involved in the uptake of xenobiotics tributylmethylammonium (TBuMA), quinidine, N-methyl-quinine (NMQ), N-methyl-quinidine (NMQD) N-(4,4-azo-n-pentyl)-quinuclidine (APQ), azidoprocainamide methoiodide (AMP), N-(4,4-azo-n-pentyl)-21-deoxyajmalinium (APDA), and 4-(4-(dimethylamino)styryl)-N-methylpyridinium (ASP).
SLC22A1 is also known as HOCT1, OCT1, oct1_cds.
