Inositol Polyphosphate-5-Phosphatase 145kDa (INPP5D)

INPP5D is a member of the inositol polyphosphate-5-phosphatase (INPP5) family and encodes a protein with an N-terminal SH2 domain, an inositol phosphatase domain, and two C-terminal protein interaction domains. Expression of this protein is restricted to hematopoietic cells where its movement from the cytosol to the plasma membrane is mediated by tyrosine phosphorylation. At the plasma membrane, the protein hydrolyzes the 5' phosphate from phosphatidylinositol (3,4,5)-trisphosphate and inositol-1,3,4,5-tetrakisphosphate, thereby affecting multiple signaling pathways. Overall, the protein functions as a negative regulator of myeliod cell proliferation and survival. Alternate transcriptional splice variants, encoding different isoforms, have been characterized.