[Comparative analysis of post-translational modifications in plasma proteome of patients with cerebral ischemia based on HPLC-MS/MS method]

Bioinformatic identification of proteins with altered PTM levels in a mouse line established to study the mechanisms of the development of fibromuscular dysplasia

Data from a mass spectrometry experiment of a mouse line developed to study the mechanisms of fibromuscular dysplasia and deposited by d'Escamard et al. in ProteomeXchange (PXD051750) have been analyzed. Identification of peptides with post-translational modifications (PTMs) was repeated using more stringent conditions than in the original work. The following modifications were considered during analysis of changes in the PTM levels in experimental and control groups of mice: acetylation of lysine residue and N-terminal protein peptide, ubiquitination of lysine residue, phosphorylation of serine, threonine and tyrosine residues, and deamination of asparagine and glutamine residues. The multistage analysis resulted in selection of 23 proteins with PTMs for which different levels of modification between experimental and control groups could be assumed. These included six proteins with N-terminal protein acetylation, which were particularly interesting: P80318 (T-complex protein 1 subunit gamma), P43274 (Histone H1.4), P97823 (Acyl-protein thioesterase 1), P63242 (Eukaryotic translation initiation factor 5A-1), Q3UMT1 (Protein phosphatase 1 regulatory subunit 12C), Q9D8Y0 (EF-hand domain-containing protein D2). Thus, repeated bioinformatic analysis of the data deposited in the specialized databases resulted in detection of changes in the level of N-terminal acetylation of proteins that might be functionally significant in the mechanisms underlying the development of fibromuscular dysplasia.

Acetylation, methylation, and ubiquitination of proteins in experimental ischemic stroke in mice: a bioinformatics analysis

The experimental results available in the ProteomeXchange database (accession code PXD016538) (Simats et al. (2020) Molecular and Cellular Proteomics, 19(12), 1921-1936) obtained using a comprehensive multi-omics approach were analyzed in mouse blood to identify potential biomarkers of ischemic stroke. Acetylation, methylation, and ubiquitination were considered as post-translational modifications. The analysis of the significance of changes in the level of protein modification was evaluated for ischemic tissue in comparison with tissue undamaged by stroke and control taken from mice after sham operation. At the level of statistically significant differences according to the Mann-Whitney test (p < 0.05), 2 proteins were found (Q02248 and Q8BL66); for additional 7 proteins, the differences were at the level of a statistical trend (p < 0.1). For 7 of 9 selected proteins there are reports in the literature, for their association with cerebral ischemia.

[The bioinformatic identification of proteins with varying levels of post-translational modifications in experimental ischemic stroke in mice]

The experimental data obtained by Simats A. et al. (Molecular and Cellular Proteomics, 2020, 19(12), 1921-1936) was analysed using a bioinformatic approach. Original experimental results available in the ProteomeXchange database were obtained using a comprehensive multidomain approach to identify potential blood biomarkers in ischemic stroke in mice. The identification of peptides with post-translational modification (PTM) was performed by us using the raw data (accession code PXD016538). Only phosphorylation and deamination were considered as PTMs. Different combinations of data sets (ischemic tissue with intact tissue, ischemic tissue with control taken from mice after sham surgery, etc.) were compared both in terms of the ratio of abundance for the modified peptide to the unmodified variant and in terms of absolute values of abundance. The most likely change in precisely PTM levels was shown for 27 proteins, which include dynamin, glycogen phosphorylase and 70 kDa heat shock protein.