Vacuolar protein sorting-associated protein 34 (VPS34)

Vacuolar protein sorting-associated protein 34 (VPS34) is the only known member of the class III phosphoinositide 3‑kinases. It functions as a lipid kinase that phosphorylates phosphatidylinositol to generate phosphatidylinositol 3-phosphate [PtdIns(3)P], a crucial signaling molecule involved in membrane trafficking events such as endocytosis, autophagy initiation, and lysosomal/vacuolar function. VPS34 forms multi-protein complexes with regulatory subunits to mediate distinct cellular processes—most notably autophagosome nucleation and endosomal sorting. Its activity is essential for normal cell homeostasis; dysregulation has been linked to diseases including cancer and viral infections due to its central role in controlling intracellular degradation pathways.

Other names

Phosphatidylinositol 3-kinase catalytic subunit type 3Class III phosphatidylinositol 3-kinaseVps34p (in yeast)

Inhibition of VPS34 blocks the formation of PtdIns(3)P, thereby disrupting autophagosome formation and endosomal trafficking. This can suppress cellular processes like autophagy that are critical for cell survival under stress or infection.