Regulatory subunit of the PI3K complex that mediates formation of phosphatidylinositol 3-phosphate, different complex forms are believed to play a role in multiple membrane trafficking pathways: PI3KC3-C1 is involved in initiation of autophagosomes and PI3KC3-C2 in maturation of autophagosomes and endocytosis. Involved in regulation of degradative endocytic trafficking and cytokinesis, probably in the context of PI3KC3-C2.,PIK3R4,VPS15,p150,Epigenetics & Nuclear Signaling,Translation Control,Regulation of eIF4 and p70 S6 Kinase,Signal Transduction,Kinase,Serine/threonine kinases,PI3K-Akt Signaling Pathway,mTOR Signaling Pathway,ErbB-HER Signaling Pathway,MAPK-Erk Signaling Pathway,MAPK-JNK Signaling Pathway,Cell Biology & Developmental Biology,Apoptosis,Mitochondrial Control of Apoptosis,Inhibition of Apoptosis,Autophagy,Cell Adhesion,Cytoskeleton,Microtubules,Actins,TGF-b-Smad Signaling Pathway,ESC Pluripotency and Differentiation,Endocrine & Metabolism,Lipid Metabolism,AMPK Signaling Pathway,Warburg Effect,Immunology & Inflammation,T Cell Receptor Signaling Pathway,IL-6 Receptor Signaling Pathway,NF-kB Signaling Pathway,Cardiovascular,Angiogenesis,Regulators,PIK3R4