Inositol polyphosphate-5-phosphatase J (INPP5J)

Inositol polyphosphate-5-phosphatase J (INPP5J) is a cytoplasmic enzyme that dephosphorylates multiple inositol phosphates and phosphatidylinositols, including phosphatidylinositol 4,5-bisphosphate and inositol 1,4,5-trisphosphate, by removing a phosphate from the 5-position[1][3][6]. Through these activities, INPP5J modulates vital cell signaling pathways, particularly those involving phosphoinositide metabolism, and has been shown to act as a suppressor of oncogenic PI3K/AKT signaling[8]. Mutations in INPP5J are associated with Lowe Oculocerebrorenal syndrome and Joubert syndrome 1[1]. The enzyme is expressed in various tissues and is predicted to be involved in cytoskeletal regulation and cellular signaling[4][7]. No currently approved drugs target INPP5J specifically, nor is it in common use as a biomarker or therapeutic target at this time.

Other names

Phosphatidylinositol 4,5-bisphosphate 5-phosphatase APIB5PAPIPPINPP5Inositol polyphosphate 5-phosphatase JPhosphatidylinositol 1,3,4,5-tetrakisphosphate 5-phosphatasePhosphatidylinositol 1,4,5-trisphosphate 5-phosphatase

No clinically validated mechanisms of action for drugs targeting INPP5J specifically; enzyme activity could theoretically be targeted to regulate PI3K/AKT pathway signaling.