Global redox proteome and phosphoproteome analysis reveals redox switch in Akt

Abstract

Protein oxidation sits at the intersection of multiple signalling pathways, yet the magnitude and extent of crosstalk between oxidation and other post-translational modifications remains unclear. Here, we delineate global changes in adipocyte signalling networks following acute oxidative stress and reveal considerable crosstalk between cysteine oxidation and phosphorylation-based signalling. Oxidation of key regulatory kinases, including Akt, mTOR and AMPK influences the fidelity rather than their absolute activation state, highlighting an unappreciated interplay between these modifications. Mechanistic analysis of the redox regulation of Akt identified two cysteine residues in the pleckstrin homology domain (C60 and C77) to be reversibly oxidized. Oxidation at these sites affected Akt recruitment to the plasma membrane by stabilizing the PIP3 binding pocket. Our data provide insights into the interplay between oxidative stress-derived redox signalling and protein phosphorylation networks and serve as a resource for understanding the contribution of cellular oxidation to a range of diseases.

Colchicine treatment impairs skeletal muscle mitochondrial function and insulin sensitivity in an age‐specific manner

“…This is in accordance with the recent finding that glucose uptake was impaired without apparent changes in insulin signaling upstream of GLUT4 translocation in response to treatment with a mitochondria‐targeted superoxide‐generating compound (Mito‐PQ) 25 . This dissociation between classic insulin signaling and glucose uptake may be related to the recent discovery of cysteine redox‐switches within proteins that regulate glucose uptake 82 . Thus, the observed colchicine‐induced mitochondrial oxidant emission may impair GLUT4 translocation and glucose uptake by thiol‐oxidation events downstream of TBC1D4.…”

Both Hypoxia-Inducible Factor 1 and MAPK Signaling Pathway Attenuate PI3K/AKT via Suppression of Reactive Oxygen Species in Human Pluripotent Stem Cells

“…These findings further support the hypothesis that ROS mediate downregulation of PTEN activity in hPSCs. AKT itself was also shown to be reversibly oxidized by ROS, which strengthens its PIP 3 binding pocket, recruitment to the plasma membrane, and its activation (Su et al, 2019 ). Our results show that the possible AKT oxidation does not induce phosphorylation without the activity of PI3K ( Figure 2D ).…”

“…Our results show that the possible AKT oxidation does not induce phosphorylation without the activity of PI3K ( Figure 2D ). Seemingly, the ROS-mediated strengthening of the PIP 3 binding pocket on the AKT molecule (Su et al, 2019 ) cooperates with the reversible oxidation of PTEN to induce AKT phosphorylation.…”

Alteration of protein homeostasis mediates the interaction of Pseudomonas aeruginosa with Staphylococcus aureus

“…For the identification of potential P. aeruginosa ClpXP substrates, t ‐test‐based (two‐tailed) statistics was applied on the log 2 ‐transformed LFQ values. Protein with fold change ≥ 1.5 in LFQ intensities and p ≤ .05 was considered as protein with significant abundant differences according to the previous publications (Sun et al , 2013; Liu et al , 2014; Su et al , 2019). Proteins without valid LFQ intensity in the ClpXP‐treated group but with valid LFQ intensity in all three samples of the control experiment was also considered as candidates for the in vitro substrates of P. aeruginosa ClpXP.…”