Reaction: Hydrolysis of PIP3 to PI(3,4)P2
- in pathway: Downstream TCR signaling
After the generation of PIP3 by PI3K, a part of it is further dephosphorylated to generate other forms of PI which are also involved in signaling. Two major routes for the degradation of PIP3 exists: dephosphorylation by the haematopoietic-specific SH2 domain-containing inositol 5' phosphatase SHIP-1 and dephosphorylation by the 3' phosphoinositide phosphatase PTEN.
SHIP-1 appears to set an activation threshold on T cell signaling. SHIP-1 phosphatase activity removes the 5' phosphate of PIP3 and generate phosphatidylinositol 3,4-bisphosphate. PI(3,4)P2 along with PIP3 preferentially binds to the PH domains of PKB and PDK1.
SHIP-1 appears to set an activation threshold on T cell signaling. SHIP-1 phosphatase activity removes the 5' phosphate of PIP3 and generate phosphatidylinositol 3,4-bisphosphate. PI(3,4)P2 along with PIP3 preferentially binds to the PH domains of PKB and PDK1.
Reaction - small molecule participants:
Pi [cytosol]
PI(3,4)P2 [plasma membrane]
H2O [cytosol]
PI(3,4,5)P3 [plasma membrane]
Reactome.org reaction link: R-HSA-202237
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Reaction input - small molecules:
water
1-phosphatidyl-1D-myo-inositol 3,4,5-trisphosphate(7-)
Reaction output - small molecules:
hydrogenphosphate
1-phosphatidyl-1D-myo-inositol 3,4-bisphosphate
Reactome.org link: R-HSA-202237