Fig. 1: rp-SILAC strategy reveals aspirin-mediated inhibition of protein degradation in HeLa cells.

a Experimental scheme of the rp-SILAC strategy. This strategy utilizes quantification between the MS signals representing the pre-existing proteins to analyze degradation. The treatment with aspirin (b) or ATN combo (c) leads to the suppression of protein degradation. Aspirin or ATN combo treatment decreases global degradome slightly, but does not affect proteins’ abundance significantly. The distance (“D”) and p-value were calculated using the two-tailed Kolmogorov-Smirnov test (Proteome: n = 3 independent experiments; Degradome: n = 4 independent experiments). Volcano plots display the change in degradome caused by aspirin (d) or ATN combo (e) treatment. Proteins regulated by degradation (p < 0.05) are highlighted in red (FC > 1) or blue (FC < 1) dots, and the number of these proteins is displayed on the plots. Statistical tests were performed using one-sample two-tailed t-test with Benjamini-Hochberg multiple test correction. Melting temperature of degradation-changed proteins (p < 0.05) and those unchanged (p ≥ 0.05) with aspirin (f) or ATN combo (g) treatment. Boxes represent the interquartile range (25th to 75th percentile) for melting temperature, and whiskers extend from the 2.5th to the 97.5th percentile of the data. Two-tailed Mann-Whitney U test was used to analyze the significance of differences between groups (Aspirin: n = 2214 and 1364; ATN: n = 2281 and 1059). h Gene Ontology analysis of degradation-changed proteins. Fisher’s Exact test, with Benjamini-Hochberg adjusted p-values, is used to measure gene enrichment in annotation terms. Source data are provided as a Source Data file.