Inositol Polyphosphate-1-Phosphatase (INPP1)

INPP1, one of the enzymes involved in phosphatidylinositol signaling pathways. This enzyme removes the the phosphate group at position 1 of the inositol ring from the polyphosphates inositol 1,4-bisphosphate and inositol 1,3,4-trisphophosphate.The 1.74-kb human cDNA predicted a protein of 399 amino acids. The human and bovine enzymes show 84% amino acid sequence identity. Northern blot analysis of a variety of human tissues demonstrated that a 1.9-kb mRNA is ubiquitously expressed, with highest levels in pancreas and kidney.Transfection and overexpression of INPP1 reduced expression of hypertrophy markers and reduced the increase in ribosomal DNA transcription. Ins(1,4)P2 levels were also increased in mouse hearts hypertrophied by pressure overload.