PIK3C3

VPS34, encoded by PIK3C3, is the only class III phosphoinositide 3-kinase in mammals and the sole enzyme dedicated to producing PI3P from phosphatidylinositol. It assembles into distinct complexes with the regulatory subunit VPS15 and with Beclin 1 together with either ATG14 or UVRAG, which direct it to autophagic or endosomal membranes. Through localized PI3P synthesis, VPS34 nucleates autophagosome formation, drives endosome-to-Golgi trafficking and supports receptor sorting. Its central position in autophagy makes VPS34 a tool and target for compounds such as wortmannin and VPS34-IN1, and it is studied in cancer, neurodegeneration and infection.