PI3KC3 is a catalytic subunit of the PI3K complex involved in the transport of lysosomal enzyme precursors to lysosomes. This enzyme acts catalytically to convert 1-phosphatidyl-1D-myo-inositol to 1-phosphatidyl-1D-myo-inositol 3-phosphate. Macroautophagy is the major inducible pathway for the general turnover of cytoplasmic constituents in eukaryotic cells, it is also responsible for the degradation of active cytoplasmic enzymes and organelles during nutrient starvation. Macroautophagy involves the formation of double-membrane bound autophagosomes which enclose the cytoplasmic constituent targeted for degradation in a membrane bound structure, which then fuse with the lysosome (or vacuole) releasing a single-membrane bound autophagic bodies which are then degraded within the lysosome (or vacuole). The regulation of the Beclin 1-PI3KC3 complex lipid kinase activity is a critical element in the autophagy signaling pathway.
Synonyms: Phosphatidylinositol 3-kinase catalytic subunit type 3, PtdIns-3-kinase type 3, PI3-kinase type 3, PI3K type 3, Phosphoinositide-3-kinase class 3, Phosphatidylinositol 3-kinase p100 subunit, vps34
Pathways: Phagosome, Inositol phosphate metabolism, Phosphatidylinositol signaling system, Regulation of autophagy, Tuberculosis