Protein kinase C regulates amino acid transporter ATB0,+

• DOI: 10.1016/j.bbrc.2012.04.106
• Publication Date: 2012-04-27T09:45:49Z
• Authors: Łukasz Samluk; Magdalena Czeredys; Krzysztof Skowronek; Katarzyna A. Nałęcz
• Keywords: Immunoprecipitation; Amino acid transporter

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.