Cloning and functional characterization of a potential-sensitive, polyspecific organic cation transporter (OCT3) most abundantly expressed in placenta.

Article Details

Citation

Kekuda R, Prasad PD, Wu X, Wang H, Fei YJ, Leibach FH, Ganapathy V

Cloning and functional characterization of a potential-sensitive, polyspecific organic cation transporter (OCT3) most abundantly expressed in placenta.

J Biol Chem. 1998 Jun 26;273(26):15971-9.

PubMed ID
9632645 [ View in PubMed
]
Abstract

We have isolated a cDNA from rat placenta which, when expressed heterologously, mediates the transport of a wide spectrum of organic cations. The cDNA codes for a protein of 551 amino acids containing 12 putative transmembrane domains. Northern blot analysis indicates that this transporter is expressed most abundantly in the placenta and moderately in the intestine, heart, and brain. The expression is comparatively low in the kidney and lung and is undetectable in the liver. This transporter is distinct from the previously cloned organic cation transporters (OCT1, OCT2, NKT, NLT, RST, and OCTN1). When expressed in HeLa cells, the cDNA induces the transport of tetraethylammonium and guanidine. Competition experiments indicate that this transport process recognizes a large number of organic cations, including the neurotoxin 1-methyl-4-phenylpyridinium, as substrates. The cDNA-induced transport is markedly influenced by extracellular pH. However, when expressed in Xenopus laevis oocytes, the cDNA-induced transport is electrogenic, associated with the transfer of positive charge into the oocytes. Under voltage clamp conditions, tetraethylammonium evokes inward currents that are concentration- and potential-dependent. This potential-sensitive organic cation transporter, designated as OCT3, represents a new member of the OCT gene family.

DrugBank Data that Cites this Article

Drug Transporters
DrugTransporterKindOrganismPharmacological ActionActions
CholineSolute carrier family 22 member 3ProteinHumans
Unknown
Inhibitor
Details
Choline salicylateSolute carrier family 22 member 3ProteinHumans
Unknown
Inhibitor
Details
CimetidineSolute carrier family 22 member 3ProteinHumans
Unknown
Substrate
Inhibitor
Details
DesipramineSolute carrier family 22 member 3ProteinHumans
Unknown
Inhibitor
Details
GuanidineSolute carrier family 22 member 3ProteinHumans
Unknown
Substrate
Inhibitor
Details
NicotineSolute carrier family 22 member 3ProteinHumans
Unknown
Inhibitor
Details