Restraining PI3K: mTOR signalling goes back to the membrane
Date
2005ICR Author
Author
Harrington, LS
Findlay, GM
Lamb, RF
Type
Journal Article
Metadata
Show full item recordAbstract
The lipid kinase phosphoinositide 3-kinase (PI3K) is activated in response to various extracellular signals including peptide growth factors such as insulin and insulin-like growth factors (IGFs). Phosphatidylinositol (3,4,5)-trisphosphate [PtdIns(3,4,5)P3] generated by PI3K is central to the diverse responses elicited by insulin, including glucose homeostasis, proliferation, survival and cell growth. The actions of lipid phosphatases have been considered to be the main means of attenuating PI3K signalling, whereby the principal 3-phosphatase – phosphatase and tensin homologue deleted on chromosome 10 (PTEN) – dephosphorylates PtdIns(3,4,5)P3, reversing the action of PI3K. Recently, however, another pathway of regulation of PI3K has been identified in which activation of PI3K itself is prevented. This finding, together with earlier work, strongly suggests that a major form of negative feedback inhibition of PI3K results from activated growth signalling via mammalian target of rapamycin (mTOR) and the p70 S6 kinase (S6K) – a pathway that could have consequences for the development of type 2 diabetes and tuberous sclerosis complex.
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Language
eng
License start date
2005
Citation
Trends in Biochemical Sciences, 2005, 30 pp. 35 - 42