Oral Presentation HUPO 2019 - 18th Human Proteome Organization World Congress

Global redox proteome and phosphoproteome analysis reveals novel insights into the Insulin Signaling Network (#165)

Sean Humphrey 1 , Daniel Fazakerley 1 , Pengyi Yang 1 , Tim Zhiduan Su 2 , James Burchfield 1 , David James 1 3
  1. Charles Perkins Centre, School of Life & Environmental Science, The University of Sydney, Sydney, NSW, Australia
  2. Charles Perkins Centre, School of Life & Environmental Science, The University of Sydney, Sydney, NSW, Australia
  3. School of Medicine, The University of Sydney, Sydney, NSW, Australia

We have previously used phosphoproteomics to map the insulin signalling network in adipocytes revealing more than 2,000 insulin responsive phosphosites. More recently, we have used similar approaches to map changes in the phosphoproteome across multiple models of insulin resistance revealing major changes in the entire signalling network across all models. Because insulin resistance also involves changes in oxidative stress, here we endeavoured to find the intersection between the redox and phospho-proteomes. Our integrative analysis revealed widespread and complex crosstalk between oxidative stress-induced cysteine oxidation and phosphorylation-based signalling. In particular, we observed that oxidation of key regulatory nodes (Akt, mTOR and AMPK) influences the fidelity of signalling via these nodes rather than absolute activity, providing an underappreciated interplay between these modifications. Mechanistic analysis of the redox regulation of Akt identified that two cysteine residues in the pleckstrin homology domain of Akt (C60 and C77) are likely reversibly oxidised and this regulates recruitment of Akt to PIP3 at the plasma membrane via reconfiguration of the PH domain structure. Overall, these multi-omics datasets provide insight into how redox signalling driven by oxidative stress interacts with protein phosphorylation and should serve as a useful resource for dissecting oxidative stress-induced PTMs and understanding their contribution to a variety of diseases.