The amino acid transporter B(0)AT1 (SLC6A19) accomplishes concentrative cellular uptake of neutral amino acids. The carrier is stimulated by serum- & glucocorticoid-inducible kinase (SGK) isoforms. SGKs are related to PKB/Akt isoforms, which stimulate several amino acid transporters. PKB/Akt modulates glucose transport in part by phosphorylating and thus activating phosphatidylinositol-3-phosphate-5-kinase PIKfyve, which fosters carrier protein insertion into the cell membrane. The present study explored whether PKB/AKT and/or PIKfyve stimulate SLC6A19. To this end, SLC6A19 was expressed in Xenopusoocytes with or without wild type PKB/AKT or inactive ^T308AS473APKB/AKT without or with wild type PIKfyve or PKB/Akt-resistant ^S318APIKfyve. Electrogenic amino acid transport was determined by dual electrode voltage clamping. In SLC6A19-expressing oocytes but not in oocytes injected with water or PKB/AKT alone, the addition of leucine (2 mM) to the bath generated a current (I_le), which was significantly increased following coexpression of PKB/AKT, but not by coexpression of ^T308AS473APKB/AKT. The effect of PKB/Akt was augmented by additional coexpression of PIKfyve but not of ^S318APIKfyve. Coexpression of PKB/AKT enhanced the maximal transport rate without significantly modifying the affinity of the carrier. The decline of I_le following inhibition of carrier insertion by brefeldin A (5 mM) was similar in the absence and presence of PKB/AKT indicating that PKB/AKT stimulated carrier insertion into rather than inhibiting carrier retrival from the cell membrane. In conclusion, PKB/AKT up-regulates SLC6A19 activity which may foster amino acid uptake into PKB/AKT-expressing cells.