title: Protein kinase C regulates amino acid transporter ATB(0,+).
abstract: ATB(0,+) (SLC6A14) is a transporter specific towards neutral and cationic amino acids, known to be up-regulated in malignant tumor cells. We cloned cDNA for rATB(0,+) and expressed it in HEK 293 cells. The ATB(0,+) over-expression correlated with increased l-leucine transport, stimulated by protein kinase C (PKC) activator and attenuated by PKC inhibitors. Transport stimulation was correlated with phosphorylation on serine moiety of the transporter and its augmented plasma membrane presence. Immunoprecipitation experiments demonstrated ATB(0,+) interaction with PKCα, but not with other classical or novel PKC isoforms. Immunocytochemistry experiments showed a transfer of PKCα to plasma membrane upon phorbol ester activation and co-localization with ATB(0,+). The observed regulation of ATB(0,+) by PKC correlates with high activity of both proteins reported for cancer cells.
authors.affiliation: Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw, Poland.
authors.forename: Lukasz
authors.initials: L
authors.lastname: Samluk
authors.forename: Magdalena
authors.initials: M
authors.lastname: Czeredys
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Skowronek
authors.forename: Katarzyna A
authors.initials: KA
authors.lastname: Nałęcz
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D003001:Cloning, Molecular; D057809:HEK293 Cells; D006801:Humans; D047468:Immunoprecipitation; D050479:Neurotransmitter Transport Proteins / Q000235:genetics / Q000378:metabolism*; D010703:Phorbol Esters / Q000494:pharmacology; D010766:Phosphorylation; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats
chemical_list: D050479:Neurotransmitter Transport Proteins; D010703:Phorbol Esters; C515774:Slc6a14 protein, rat; D011493:Protein Kinase C