Sandbox Reserved 822: Difference between revisions

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Once activated by growth factors, various local responses, such as cell growth, cell survival and cell movement are regulated by the highly conserved PDK1 pathway.  
Once activated by growth factors, various local responses, such as cell growth, cell survival and cell movement are regulated by the highly conserved PDK1 pathway.  


Therefore PDK1 binds to the lipid products of [[PI3K]], PtdIns(3,4,5)P<sub>3</sub> and PtdIns(3,4)P<sub>2</sub> (see 'Ligand Interaction'). Once localized to the plasma membrane PDK1 can phosphorylate PKB/Akt and thereby activate mTOR, which plays a major role in ageing mechanisms and Alzheimer’s disease. Other tumor supressors such as the phosphatidylinositol 3′-phosphatase [[PTEN]] act to down-regulate signaling from PI3K to PDK1 and PKB as well. <ref>Hemmings, Brian A., and David F. Restuccia. "PI3K-PKB/Akt Pathway." Cold Spring Harbor Perspectives in Biology 4.9 (2012) [http://cshperspectives.cshlp.org/content/4/9/a011189.full DOI:10.1101/cshperspect.a011189]</ref>
Therefore PDK1 binds to the lipid products of [[PI3K]], PtdIns(3,4,5)P<sub>3</sub> and PtdIns(3,4)P<sub>2</sub> (see 'Ligand Interaction'). Once localized to the plasma membrane PDK1 can phosphorylate PKB/Akt and thereby activate [http://en.wikipedia.org/wiki/Mammalian_target_of_rapamycin mTOR], which plays a major role in ageing mechanisms and Alzheimer’s disease. Other tumor supressors such as the phosphatidylinositol 3′-phosphatase [[PTEN]] act to down-regulate signaling from PI3K to PDK1 and PKB as well. <ref>Hemmings, Brian A., and David F. Restuccia. "PI3K-PKB/Akt Pathway." Cold Spring Harbor Perspectives in Biology 4.9 (2012) [http://cshperspectives.cshlp.org/content/4/9/a011189.full DOI:10.1101/cshperspect.a011189]</ref>


Some other substrates of PDK1 are usually activated when the lipid-binding function of the protein is inhibited. Hence, not all PDK1 mediated reactions depend necessarily on the PH domain of PDK1. <ref>Scheid, Michael P., Michael Parsons, and James R. Woodgett. "Phosphoinositide-dependent phosphorylation of PDK1 regulates nuclear translocation." Molecular and cellular biology 25.6 (2005): 2347-2363. [http://mcb.asm.org/content/25/6/2347.full DOI:10.1128/MCB.25.6.2347-2363.2005]</ref>  
Some other substrates of PDK1 are usually activated when the lipid-binding function of the protein is inhibited. Hence, not all PDK1 mediated reactions depend necessarily on the PH domain of PDK1. <ref>Scheid, Michael P., Michael Parsons, and James R. Woodgett. "Phosphoinositide-dependent phosphorylation of PDK1 regulates nuclear translocation." Molecular and cellular biology 25.6 (2005): 2347-2363. [http://mcb.asm.org/content/25/6/2347.full DOI:10.1128/MCB.25.6.2347-2363.2005]</ref>