A conserved VPS34-PIKfyve-TRPML1-myosin II axis regulates the speed of amoeboid cell migration.

Amoeboid cell migration is key to efficient T cell immunity. Spatial polarization of organelles within cells, including endo-lysosomes, is a prerequisite of migration. However, how ultrastructural polarization is linked to the signaling requirements governing T cell migration remains unknown. Here we show that signaling molecules generated by endo-lysosome-localized kinases regulate velocity of amoeboid migration. Specifically, imaging of T cells identifies accumulation of endo-lysosomes decorated with the lipid kinases VPS34-PIKfyve at the uropod of polarized cells. Activity of VPS34 and PIKfyve regulates speed, but not directedness, of migrating T cells. Mechanistically, PI(3,5)P2 generated by the sequential action of VPS34 and PIKfyve, mediates Ca2+ efflux from lysosomes via the mucolipin TRP cation channel 1 (TRPML1), thus controlling activity of myosin IIA and hence the generation of propulsive force through retrograde actin flow. The VPS34-PIKfyve kinases also regulate velocity of myeloid cells, as well as of the amoeba Dictyostelium discoideum - establishing the axis as an evolutionarily conserved speed control system of amoeboid cell migration.