title: The mTOR (mammalian target of rapamycin) kinase maintains integrity of mTOR complex 2.
abstract: In higher eukaryotes, growth factors promote anabolic processes and stimulate cell growth, proliferation, and survival by activation of the phosphoinositide 3-kinase (PI3K)/Akt pathway. Deregulation of PI3K/Akt signaling is linked to human diseases, including cancer and metabolic disorders. The PI3K-dependent signaling kinase complex mTORC2 (mammalian target of rapamycin complex 2) has been defined as the regulatory Ser-473 kinase of Akt. The regulation of mTORC2 remains very poorly characterized. We have reconstituted mTORC2 by its assembly in vitro or by co-expression its four essential components (rictor, SIN1, mTOR, mLST8). We show that the functional mTOR kinase domain is required for the mTORC2 activity as the Ser-473 kinase of Akt. We also found that mTOR by phosphorylation of SIN1 prevents its lysosomal degradation. Thus, the kinase domain of mTOR is required for the functional activity of mTORC2, and it controls integrity of mTORC2 by maintaining the protein stability of SIN1.
authors.affiliation: Department of Molecular and Cellular Oncology, University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.
authors.forename: Chien-Hung
authors.initials: CH
authors.lastname: Chen
authors.forename: Dos D
authors.initials: dos D
authors.lastname: Sarbassov
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation / Q000502:physiology; D055550:Protein Stability; D017434:Protein Structure, Tertiary; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D058570:TOR Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; D014157:Transcription Factors; C493245:CRTC2 protein, human; C493277:MAPKAP1 protein, human; C546842:MTOR protein, human