Exploring the Role of Redox-Regulated Switch Proteins Mediating Adaptation and Life Cycles of Cellular Proteins

Cellular redox status affects diverse cellular functions, including proliferation, protein homeostasis, and aging. Thus, individual differences in redox status can give rise to distinct sub-populations even among cells with identical genetic backgrounds. Here, we have established a robust methodology to track redox status at single-cell resolution using the in-vivo encoded redox-sensitive probes. Our method allows the identification and charactaerization of redox heterogeneity in cells and specific organells. Incorporation of proteomics into this pipline allowed us to identify distinct protein profiles and key redox-switches defining the redox status of cells during aging, cell cycle and cellular proliferation.

To identify redox-switch proteins from distinct biological functions, we have applied this methodology to a specially designed barcoded yeast library, and defined dominant biological functions associated with either cellular oxidation or reduction. We identified potential moonlighting proteins, many of which belong to protein quality control and cell cycle pathways.

To close the cycle, we defined redox-regulation activity of one of the highly conserved, key protein and protein degradation pathways, Cdc48 (VCP /p97). Using a combination of structural mass spectrometry, computational modeling and cell biology, we found that the oxidation status of Cdc48 defines its interaction with canonic cofactors and subsequent involvement in maintaining protein homeostasis through degradation, the unfolded protein response, cellular viability, and protein localization during chronological aging.

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Radzinski M., et al, eLife, 2018, 7: e37623

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Oppenheim T, et al., Structure, 2022 under revision

Radzinski M., et al, BioRxiv 733709 , in submission to eLife