FEATURES

FAMILY

DESCRIPTION

Also known as PK3C3_HUMAN, PIK3C3, VPS34. Catalytic 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. As part of PI3KC3-C1, promotes endoplasmic reticulum membrane curvature formation prior to vesicle budding (PubMed:32690950). Involved in regulation of degradative endocytic trafficking and required for the abcission step in cytokinesis, probably in the context of PI3KC3-C2 (PubMed:20643123, PubMed:20208530). Involved in the transport of lysosomal enzyme precursors to lysosomes. Required for transport from early to late endosomes (By similarity). Component of the PI3K (PI3KC3/PI3K-III/class III phosphatidylinositol 3-kinase) complex the core of which is composed of the catalytic subunit PIK3C3, the regulatory subunit PIK3R4 and BECN1 associating with additional regulatory/auxilliary subunits to form alternative complex forms. Alternative complex forms containing a forth regulatory subunit in a mutually exclusive manner are: the PI3K complex I (PI3KC3-C1) containing ATG14, and the PI3K complex II (PI3KC3-C2) containing UVRAG. PI3KC3-C1 displays a V-shaped architecture with PIK3R4 serving as a bridge between PIK3C3 and the ATG14:BECN1 subcomplex. Both, PI3KC3-C1 and PI3KC3-C2, can associate with further regulatory subunits such as RUBCN, SH3GLB1/Bif-1 and AMBRA1 (PubMed:7628435, PubMed:19050071, PubMed:20643123, PubMed:19270696, PubMed:23878393, PubMed:25490155). PI3KC3-C1 probably associates with PIK3CB (By similarity). Interacts with RAB7A in the presence of PIK3R4 (PubMed:14617358). Interacts with AMBRA1 (By similarity). Interacts with BECN1P1/BECN2 (PubMed:23954414). Interacts with SLAMF1(PubMed:22493499). May be a component of a complex composed of RAB5A (in GDP-bound form), DYN2 and PIK3C3 (By similarity). Interacts with NCKAP1L (PubMed:16417406). Interacts with ATG14; this interaction is increased in the absence of TMEM39A (PubMed:31806350). Interacts with STEEP1; the interaction is STING1-dependent and required for trafficking of STING1 from the endoplasmic reticulum (PubMed:32690950). Interacts with YWHAG (PubMed:33473107).

EXTERNAL LINKS

PIK3C3

Phosphatidylinositol 3-kinase catalytic subunit type 3

PIK3C3

Molecular Synopsis