An organic cation transport protein mediates the transport of organic cations across the

cell membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...

. These proteins are members of the solute carrier family, subfamily 22. This family of proteins can also transport

zwitterion In chemistry, a zwitterion ( ; ), also called an inner salt or dipolar ion, is a molecule that contains an equal number of positively- and negatively-charged functional groups. : With amino acids, for example, in solution a chemical equilibrium wil ...

s and

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

s, though it is a different subfamily of solute carrier proteins than the organic anion transporters.

Proteins

{, class="wikitable sortable" border="1" , - !Abbreviation!!Protein name!!Location!!Transported solute(s), , Associated disorder(s) , - , , SLC22A1, , Solute carrier family 22 member 1, , Liver, brain (cerebellum), , , , , - , ,

SLC22A2 Solute carrier family 22 member 2 (also termed ''OCT2'' or ''organic cation transporter-2'') is a protein that in humans is encoded by the ''SLC22A2'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to d ...

, , Solute carrier family 22 member 2, , Primarily in kidney, also in brain, , , , , - , ,

SLC22A3 Solute carrier family 22 member 3 (SLC22A3) also known as the organic cation transporter 3 (OCT3) or extraneuronal monoamine transporter (EMT) is a protein that in humans is encoded by the ''SLC22A3'' gene. Polyspecific organic cation transporter ...

, , Solute carrier family 22 member 3, , Brain and kidney , ,

Histamine Histamine is an organic nitrogenous compound involved in local immune responses, as well as regulating physiological functions in the gut and acting as a neurotransmitter for the brain, spinal cord, and uterus. Since histamine was discovered ...

, dopamine, serotonin,

norepinephrine Norepinephrine (NE), also called noradrenaline (NA) or noradrenalin, is an organic chemical in the catecholamine family that functions in the brain and body as both a hormone and neurotransmitter. The name "noradrenaline" (from Latin '' ad' ...

, MPP⁺ , , , - , , SLC22A4, , Solute carrier family 22 member 4, , , , Sodium ion and

ergothioneine Ergothioneine is a naturally occurring amino acid and is a thiourea derivative of histidine, containing a sulfur atom on the imidazole ring. This compound occurs in relatively few organisms, notably actinomycetota, cyanobacteria, and certain fung ...

, , , - , , SLC22A5, , Solute carrier family 22 member 5, , , , , , Primary carnitine deficiency , - , , SLC22A6, , Solute carrier family 22 member 6, , , , , , , - , ,

SLC22A7 Solute carrier family 22 member 7 is a protein that in humans is encoded by the gene ''SLC22A7''. The protein encoded by this gene is involved in the sodium-independent transport and excretion of organic anions, some of which are potentially toxi ...

, , Solute carrier family 22 member 7, , , , , , , - , ,

SLC22A8 Solute carrier family 22 member 8, or organic anion transporter 3 (OAT3), is a protein that in humans is encoded by the ''SLC22A8'' gene. Function OAT3 is involved in the transport and excretion of organic ions some of which are drugs (e.g., ...

, , Solute carrier family 22 member 8, , , , , , , - , , SLC22A9, , Solute carrier family 22 member 9, , , , , , , - , , SLC22A10, , Solute carrier family 22 member 10, , , , , , , - , ,

SLC22A11 Solute carrier family 22 member 11 is a protein that in humans is encoded by the ''SLC22A11'' gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''gen ...

, , Solute carrier family 22 member 11, , , , , , , - , , SLC22A12, , Solute carrier family 22 member 12, , Kidney, ,

Uric acid Uric acid is a heterocyclic compound of carbon, nitrogen, oxygen, and hydrogen with the formula C5H4N4O3. It forms ions and salts known as urates and acid urates, such as ammonium acid urate. Uric acid is a product of the metabolic breakdown ...

, ,

Hyperuricemia Hyperuricaemia or hyperuricemia is an abnormally high level of uric acid in the blood. In the pH conditions of body fluid, uric acid exists largely as urate, the ion form. Serum uric acid concentrations greater than 6 mg/dL for females, 7&nbs ...

and hypouricemia , - , , SLC22A13, , Solute carrier family 22 member 13, , , , , , , - , , SLC22A14, , Solute carrier family 22 member 14, , , , , , , - , , SLC22A15, , Solute carrier family 22 member 15, , , , , , , - , , SLC22A16, , Solute carrier family 22 member 16, , , , , , , - , , SLC22A17, , Solute carrier family 22 member 17, , , , , , , - , , SLC22A18, , Solute carrier family 22 member 18, , , , , , Beckwith-Wiedemann syndrome,

Wilms tumor Wilms' tumor or Wilms tumor, also known as nephroblastoma, is a cancer of the kidneys that typically occurs in children, rarely in adults.; and occurs most commonly as a renal tumor in child patients. It is named after Max Wilms, the German ...

rhabdomyosarcoma Rhabdomyosarcoma (RMS) is a highly aggressive form of cancer that develops from mesenchymal cells that have failed to fully differentiate into myocytes of skeletal muscle. Cells of the tumor are identified as rhabdomyoblasts. There are four subt ...

, adrenocortical carcinoma, and lung, ovarian, and breast cancer , - , , SLC22A19, , Solute carrier family 22 member 19, , , , , , , - , , SLC22A20, , Solute carrier family 22 member 20, , , , , , , -

References

Solute carrier family Transmembrane transporters Transport proteins