At the late endosome membrane, the PAS complex, consisting of mouse FYVE finger-containing phosphoinositide kinase (Pikfyve), yeast VAC14 homologue (VAC14), and polyphosphoinositide phosphatase aka SAC3 (FIG4), binds to the membrane via Pikfyve's FYVE finger. The Pikfyve kinase component phosphorylates phosphatidylinositol (PI) to phosphatidylinositol 5-phosphate (PI5P) (Sbrissa et al. 1999, Sbrissa et al. 2002). The PAS complex is present in the cytosol and is recruited to the membrane.