Periodic Reporting for period 2 - SULFAGING (Decoding protein persulfidation signaling)
Reporting period: 2022-04-01 to 2023-09-30
To efficiently control cellular processes, nature uses posttranslational modifications of proteins. Owning to unique sulfur chemistry, cysteine is the amino acid that could be subjected to the most diverse range of posttranslational modifications. One such modifications is caused by a gasotransmitter hydrogen sulfide (H2S), where an extra sulfur is added to cysteines forming persulfides. The pioneering work of our team in the past decade identified key mechanisms of biological chemistry of H2S, pointing out that protein persulfidation might represents the main way through which this gasotrasnmitter conveys its biological and pharmacological effects, particularly its anti-aging effects. Therefore, by combining the unique methodology for persulfide labelling developed in our group, with proteomics, metabolomics and classical biochemistry, and working on different model systems (cells, C. elegans, rodents) we intend to (i) gain high-resolution structural, functional, quantitative, and spatio-temporal information on persulfidation dynamics and position this evolutionary conserved posttranslational modification in the global cell signalling scheme, particularly in relation to other cysteine posttranslational modifications (ii) understand the intricate relation between aging and PSSH and (iii) identify the protein targets whose change of function by persulfidation is implicated in aging and disease progression. These studies are not only designed to provide contribution to the fundamental understanding of intracellular signalling, but to pave the way for the development of innovative therapeutic strategies that will permit targeted redox control of the cell metabolism and delay aging and disease progression.
We improved the dimedone switch method for persulfidation labelling and detection and performed in-depth proteomic analysis of this and other cysteine posttranslational modifications (sulfenylation, sulfonylation) in aging mice and C. elegans. Regardless of species, persulfidation declined with age affecting hundreds of proteins. In C. elegans, age-induced persulfidation decline is caused by the downregulation of all H2S-producing enzymes. We observed that some naturally occurring compounds extend lifespan and healthspan of C. elegans by globally increasing this protective posttranslational modification and by controlling anti-aging pathways. Lifespan extension effects mTOR pathway inhibition, as well as the effects of metformin, are dependent on H2S producing enzymes and global persulfidation changes. In mouse brains, thiol oxidation and hyperoxidation increased with age, while persulfidation decreased. We found that thiol oxidation/hyperoxidation of different proteins changes their biophysical properties, making them more prone to aggregate, while persulfidation prevented this. Indeed, aged mice lacking one of the H2S producing enzyme exhibit all features of age-induced Alzheimer’s disease.
These results suggest that protein persulfidation is indeed evolutionarily-conserved anti-aging mechanism that appeared when life emerged in hydrogen sulfide-rich environment of the prebioitc Earth. Identification of new pathways/therapeutic targets that affect aging and aging-associated diseases is expected. Work on characterization of potential biomarkers is also ongoing.