Acts as an adapter for myotubularin-related phosphatases (, ). Increases lipid phosphatase MTMR6 catalytic activity, specifically towards phosphatidylinositol 3,5-bisphosphate and MTMR6 binding affinity for phosphorylated phosphatidylinositols (, ). Positively regulates lipid phosphatase MTMR7 catalytic activity (By similarity). Increases MTMR8 catalytic activity towards phosphatidylinositol 3-phosphate . The formation of the MTMR6-MTMR9 complex, stabilizes both MTMR6 and MTMR9 protein levels . Stabilizes MTMR8 protein levels . Plays a role in the late stages of macropinocytosis possibly by regulating MTMR6-mediated dephosphorylation of phosphatidylinositol 3-phosphate in membrane ruffles . Negatively regulates autophagy, in part via its association with MTMR8 . Negatively regulates DNA damage-induced apoptosis, in part via its association with MTMR6 (, ). Does not bind mono-, di- and tri-phosphorylated phosphatidylinositols, phosphatidic acid and phosphatidylserine .
Subcellular locations: Cytoplasm, Cell projection, Ruffle membrane, Cytoplasm, Perinuclear region, Endoplasmic reticulum
Localizes to ruffles during EGF-induced macropinocytosis (By similarity). Colocalizes with MTMR6 to the perinuclear region . Partially localizes to the endoplasmic reticulum .
Expressed in many tissues.