Metabolic switching of PI3K-dependent lipid signals
| Autor: | Nick R. Leslie, Ian H. Batty, J. van der Kaay, C P Downes |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Leptin
Inositol Phosphates Phosphatase Biochemistry Phosphatidylinositol 3-Kinases chemistry.chemical_compound Homeostasis Humans Tensin PTEN Inositol PI3K/AKT/mTOR pathway chemistry.chemical_classification biology PTEN Phosphohydrolase Phosphoproteins Lipids Phosphoric Monoester Hydrolases Acid Anhydride Hydrolases Cell biology Oxidative Stress Enzyme chemistry Phosphatidylinositol-3 4 5-Trisphosphate 5-Phosphatases Mutation biology.protein Signal transduction Signal Transduction Proto-oncogene tyrosine-protein kinase Src |
| Zdroj: | Biochemical Society Transactions. 35:188-192 |
| ISSN: | 1470-8752 0300-5127 |
| DOI: | 10.1042/bst0350188 |
| Popis: | The lipid phosphatase, PTEN (phosphatase and tensin homologue deleted on chromosome 10), is the product of a major tumour suppressor gene that antagonizes PI3K (phosphoinositide 3-kinase) signalling by dephosphorylating the 3-position of the inositol ring of PtdIns(3,4,5)P3. PtdIns(3,4,5)P3 is also metabolized by removal of the 5-phosphate catalysed by a distinct family of enzymes exemplified by SHIP1 [SH2 (Src homology 2)-containing inositol phosphatase 1] and SHIP2. Mouse knockout studies, however, suggest that PTEN and SHIP2 have profoundly different biological functions. One important reason for this is likely to be that SHIP2 exists in a relatively inactive state until cells are exposed to growth factors or other stimuli. Hence, regulation of SHIP2 is geared towards stimulus dependent antagonism of PI3K signalling. PTEN, on the other hand, appears to be active in unstimulated cells and functions to maintain basal PtdIns(3,4,5)P3 levels below the critical signalling threshold. We suggest that concomitant inhibition of cysteine-dependent phosphatases, such as PTEN, with activation of SHIP2 functions as a metabolic switch to regulate independently the relative levels of PtdIns(3,4,5)P3 and PtdIns(3,4)P2. |
| Databáze: | OpenAIRE |
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