Inositol polyphosphate 5-phosphatase (INPP5 (or specific isoforms such as INPP5A, depending on context)[4])

Inositol polyphosphate 5-phosphatases are a family of enzymes that specifically hydrolyze the 5-position phosphate from various inositol polyphosphate substrates, including key second messengers like inositol 1,4,5-trisphosphate. These enzymes play a central role in regulating intracellular levels of bioactive phosphoinositides involved in diverse processes such as cell growth, survival, cytoskeletal dynamics, vesicle trafficking, and signal transduction. Structurally characterized by conserved catalytic domains with homology to AP endonucleases and containing motifs typical for protein/lipid phosphatases,[2] these enzymes are essential for maintaining proper cellular function. Dysregulation has been linked to mood disorders like bipolar disorder,[1] cancer progression,[2] and possibly neurodegenerative diseases due to their impact on critical signaling cascades.[1][2][4]

Other names

Inositol polyphosphate 5-phosphataseINPP5Inositol polyphosphate phosphatase[2][4]Inositol-phosphate phosphatase[1]Phosphoinositide 5-phosphatase[2]

Drugs targeting this enzyme typically act as inhibitors to modulate inositol phosphate metabolism and downstream signaling pathways. For example, lithium inhibits related enzymes by interfering with magnesium binding at active sites.