title: Dynamic adipocyte phosphoproteome reveals that Akt directly regulates mTORC2.
abstract: A major challenge of the post-genomics era is to define the connectivity of protein phosphorylation networks. Here, we quantitatively delineate the insulin signaling network in adipocytes by high-resolution mass spectrometry-based proteomics. These data reveal the complexity of intracellular protein phosphorylation. We identified 37,248 phosphorylation sites on 5,705 proteins in this single-cell type, with approximately 15% responding to insulin. We integrated these large-scale phosphoproteomics data using a machine learning approach to predict physiological substrates of several diverse insulin-regulated kinases. This led to the identification of an Akt substrate, SIN1, a core component of the mTORC2 complex. The phosphorylation of SIN1 by Akt was found to regulate mTORC2 activity in response to growth factors, revealing topological insights into the Akt/mTOR signaling network. The dynamic phosphoproteome described here contains numerous phosphorylation sites on proteins involved in diverse molecular functions and should serve as a useful functional resource for cell biologists.
authors.affiliation: Diabetes and Obesity Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010, Australia; Biological Mass Spectrometry Unit, Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010, Australia.
authors.forename: Sean J
authors.initials: SJ
authors.lastname: Humphrey
authors.affiliation: Diabetes and Obesity Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010, Australia.
authors.forename: Guang
authors.initials: G
authors.lastname: Yang
authors.affiliation: Diabetes and Obesity Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010, Australia; School of Mathematics and Statistics, University of Sydney, Camperdown, New South Wales 2006, Australia.
authors.forename: Pengyi
authors.initials: P
authors.lastname: Yang
authors.affiliation: Diabetes and Obesity Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010, Australia; Biological Mass Spectrometry Unit, Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010, Australia.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Fazakerley
authors.affiliation: Diabetes and Obesity Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010, Australia.
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Stöckli
authors.affiliation: School of Mathematics and Statistics, University of Sydney, Camperdown, New South Wales 2006, Australia.
authors.forename: Jean Y
authors.initials: JY
authors.lastname: Yang
authors.affiliation: Diabetes and Obesity Program, Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010, Australia; Biological Mass Spectrometry Unit, Garvan Institute of Medical Research, Darlinghurst, New South Wales 2010, Australia. Electronic address: d.james@garvan.org.au.
authors.forename: David E
authors.initials: DE
authors.lastname: James
mesh_terms: D016475:3T3 Cells; D017667:Adipocytes / Q000378:metabolism*; D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D007328:Insulin / Q000378:metabolism; D013058:Mass Spectrometry; D000076225:Mechanistic Target of Rapamycin Complex 2; D051379:Mice; D046912:Multiprotein Complexes / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D020543:Proteome; D040901:Proteomics; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D015398:Signal Transduction; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism*; D048868:Adaptor Proteins, Signal Transducing
chemical_list: D002352:Carrier Proteins; D007328:Insulin; D000076225:Mechanistic Target of Rapamycin Complex 2; D046912:Multiprotein Complexes; D019869:Phosphatidylinositol 3-Kinases; D020543:Proteome; D051057:Proto-Oncogene Proteins c-akt; D058570:TOR Serine-Threonine Kinases; C561937:Mapkap1 protein, mouse; D048868:Adaptor Proteins, Signal Transducing