6533b7cffe1ef96bd1258724

RESEARCH PRODUCT

Human cationic amino acid transporter hCAT-3 is preferentially expressed in peripheral tissues.

Jean-paul BoisselSabine WolfEllen I. ClossKarsten GnauertNicole Vékony

subject

MaleDNA ComplementaryGene ExpressionThymus GlandIn Vitro TechniquesBiochemistryCell LineMiceXenopus laevisComplementary DNACoding regionAnimalsHumansTissue DistributionAmino acid transporterAmino Acid SequenceCationic Amino Acid Transporterschemistry.chemical_classificationCATSBase SequenceChemistryCationic polymerizationBrainMembrane ProteinsAmino acidRatsBiochemistryCarrier proteinOocytesAmino Acid Transport Systems BasicFemaleCarrier Proteins

description

At least five distinct carrier proteins form the family of mammalian cationic amino acid transporters (CATs). We have cloned a cDNA containing the complete coding region of human CAT-3. hCAT-3 is glycosylated and localized to the plasma membrane. Transport studies in Xenopus laevis oocytes revealed that hCAT-3 is selective for cationic L-amino acids and exhibits a maximal transport activity similar to other CAT proteins. The apparent substrate affinity and sensitivity to trans-stimulation of hCAT-3 resembles most closely hCAT-2B. This is in contrast to rat and murine CAT-3 proteins that have been reported to display a very low activity and to be inhibited by neutral and anionic L-amino acids as well as D-arginine (Hosokawa, H., et al. (1997) J. Biol. Chem. 272, 8717-8722; Ito, K., and Groudine, M. (1997) J. Biol. Chem. 272, 26780-26786). Also, in adult rat and mouse, CAT-3 has been found exclusively in central neurons. Human CAT-3 expression is not restricted to the brain, in fact, by far the highest expression was found in thymus. Also in other peripheral tissues, hCAT-3 expression was equal to or higher than in most brain regions, suggesting that hCAT-3 is not a neuron-specific transporter.

yearjournalcountryeditionlanguage
2001-10-10Biochemistry
10.1021/bi011345chttps://pubmed.ncbi.nlm.nih.gov/11591158