PIK3C3:PIK3R4 phosphorylates PI to PI3P

Stable Identifier
Reaction [transition]
Homo sapiens
Locations in the PathwayBrowser
SVG |   | PPTX  | SBGN
Click the image above or here to open this reaction in the Pathway Browser
The layout of this reaction may differ from that in the pathway view due to the constraints in pathway layout

1-phosphatidyl-1D-myo-inositol 3-phosphate (PI3P) is generated largely by the Class III PI3 kinase Phosphatidylinositol 3-kinase catalytic subunit type 3 (PIK3C3, Vps34), which is found in intracellular membrane complexes with Phosphoinositide 3-kinase regulatory subunit 4 (PIK3R4, Vps150), necessary for catalytic activity, localization and stability (Florey & Overholtzer 2012, Raiborg et al. 2013). These core subunits are frequently associated with other partners such as Rab5, Beclin-1 and UVRAG.

PI3P strongly upregulates phagosomal NADPH oxidase activity (Hawkins et al. 2010). This effect is mediated by PI3P binding to the PX domain of Neutrophil cytosol factor 4 (NCF4, p40phox), a component of the NOX2 complex. PI3P controls ROS production by regulating the presence of NCF4 and NCF2 (p67phox) at the phagosomal membrane (Song ZM et al. 2017).

Literature References
PubMed ID Title Journal Year
23289851 Class III phosphatidylinositol 3-kinase and its catalytic product PtdIns3P in regulation of endocytic membrane traffic

Schink, KO, Raiborg, C, Stenmark, H

FEBS J. 2013
Catalyst Activity

1-phosphatidylinositol-3-kinase activity of PIK3C3:PIK3R4 [phagocytic vesicle membrane]

Orthologous Events
Cite Us!