Inhibition of phosphatidylinositol kinase-III alpha induces or facilitates lysosome exocytosis from microglia.

Besides degradation, lysosomes can also carry molecules for secretion out of the cell, such as ATP and cytokines, during unconventional secretion. Phosphatidylinositols and their metabolizing enzymes play important roles in the sorting and trafficking of lysosomal materials through the trans-Golgi network. The present study reveals a new function of phosphatidylinositol kinase-III alpha in the 'kiss-and-run' fusion of lysosomes at the plasma membrane to release ATP from microglia.