Novel regulatory mechanisms of mTOR signaling.
As a master regulator of cellular processes ranging from cell growth and proliferation to differentiation, the mammalian target of rapamycin (mTOR) is critically involved in a complex signaling network. mTOR appears to govern an amino acid sensing pathway that integrates with a phosphatidylinositol 3-kinase-dependent mitogenic pathway to activate the downstream effectors. Recent findings have revealed some unexpected regulatory mechanisms of mTOR signaling. A direct link between mTOR and mitogenic signals is found to be mediated by the lipid second messenger phosphatidic acid. In addition, cytoplasmic-nuclear shuttling of mTOR appears to be required for the cytoplasmic functions of this protein. A new picture of the rapamycin-sensitive signaling network is emerging, with implications in putative upstream regulators and additional downstream targets for mTOR.
Chen
J
J
Department of Cell and Structural Biology, University of Illinois at Urbana-Champaign, 601 S. Goodwin Ave. B107, Urbana, IL 61801, USA. jiechen@uiuc.edu
D000818:Animals; D006801:Humans; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000502:physiology; D010712:Phosphatidic Acids / Q000502:physiology*; D011494:Protein Kinases / Q000502:physiology*; D019893:Ribosomal Protein S6 Kinases / Q000502:physiology; D015398:Signal Transduction / Q000502:physiology; D058570:TOR Serine-Threonine Kinases
D010712:Phosphatidic Acids; D011494:Protein Kinases; C546842:MTOR protein, human; C546843:mTOR protein, mouse; D019893:Ribosomal Protein S6 Kinases; D058570:TOR Serine-Threonine Kinases; D020928:Mitogen-Activated Protein Kinases