This gene was identified as a tumor suppressor that is
mutated in a large number of cancers at high frequency. The protein
encoded this gene is a phosphatidylinositol-3,4,5-trisphosphate
3-phosphatase. It contains a tensin like domain as well as a
catalytic domain similar to that of the dual specificity protein
tyrosine phosphatases. Unlike most of the protein tyrosine
phosphatases, this protein preferentially dephosphorylates
phosphoinositide substrates. It negatively regulates intracellular
levels of phosphatidylinositol-3,4,5-trisphosphate in cells and
functions as a tumor suppressor by negatively regulating AKT/PKB
signaling pathway.
