Phosphatase and tensin homolog deleted

All phosphoinositides are found in the cytosolic half of the lipid bilayer of the plasma or intracellular compartment membranes (left part). The different kinases acting on phosphoinositides in mammalian cells are shown in solid lines and the phosphoinositide 3-kinases, in bold. The phosphoinositides counterpart pathways catalysed by known phosphatases are represented by dashed lines. The best known phosphatases are PTEN (Phosphatase and tensin homolog deleted on chromosome 10) and SHIP (SH2 domain-containing inositol 5-phosphatase). 

Phospholipid phosphatases are enzymes such as SHIP (SH2-domain containing inositide-5-phosphatase) or PTEN (phosphatase and tensin homolog deleted on chromosome 10) which dephosphorylate phosphoino-sitides. Whereas SHIP removes phosphate from the 5 ... 

Qiao, J., Kang, J., Cree, J., Evers, B. M., Chung, D. H. (2005). Gastrin-releasing peptide-induced down-regulation of tumor suppressor protein PTEN (phosphatase and tensin homolog deleted on chromosome ten) in neuroblastomas. Annals of Surgery, 241, 684-691. 

Figure 3. Pathways of phosphoinositide synthesis and interconversions. The figure shows the main pathways of phosphoinositide synthesis in mammalian cells. For the sake of clarity only the enzymatic activities (3-, 4- or 5-kinases or phosphatases) are indicated. In some cases the identification of key enzymes is mentioned (class I, II and III PI 3-kinases, PTEN, MTM, MTMR or SHIP). PI3K, phosphoinositide 3-kinase. PTEN, phosphatase and tensin homolog deleted on chromosome ten. MTM, myotubularin. MTMR, myotubular myopathy-related protein. SHIP, Src homology 2-containing inositol 5-phosphatase. PLC, phospholipase C. DAG, diacylglycerol.

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