Essential roles of PIKfyve and PTEN on phagosomal phosphatidylinositol 3-phosphate dynamics

PtdIns(3)P (phosphatidylinositol 3-phosphate) is a signaling molecule important for phagosome maturation. The major role of Vps34 in production of phagosomal PtdIns(3)P has been indicated. However, the fate of the newly generated PtdIns(3)P has not been well described. Here we show that elimination of PtdIns(3)P from phagosomal membrane was significantly delayed in RAW264.7 macrophages lacking PTEN or PIKfyve. In the PTEN-deficient cells treated with a PIKfyve inhibitor, degradation of PtdIns(3)P was almost lost, indicating that PTEN and PIKfyve are two major players in phagosomal PtdIns(3)P metabolism.

► In macrophages lacking PIKfyve, PtdIns(3)P elimination from phagosome was delayed.
► In macrophages lacking PTEN, PtdIns(3)P elimination from phagosome was delayed.
► PtdIns(3)P persisted on phagosome, when both enzymes were absent.
► PIKfyve and PTEN are major players in PtdIns(3)P elimination from phagosome.