Stimulation of the amino acid transporter SLC6A19 by JAK2

► The amino acid transporter SLC6A19 is upregulated by Janus kinase-2 JAK2. ► The V617FJAK2 mutant, causing myeloproliferative disease, is more effective. ► JAK2 inhibitor AG490 reverses stimulation of SLC6A19 by V617FJAK2. ► JAK2 enhances SLC6A19 protein insertion into the cell membrane. ► SLC6A19 may contribute to amino acid uptake into V617FJAK2 expressing tumor cells.