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.