Extended Data Fig. 7: Investigating proteasome inhibition and peptide cleavage sites.
From: Cell-autonomous innate immunity by proteasome-derived defence peptides
a, S. enterica growth in conditioned medium from cells treated with Epoxomicin (1 µM) or Leupeptin (20 µM) for 6 h. b, Bar plot of bacterial growth at 6 h. mean ± s.e.m. (n = 3 biological replicates). One-way ANOVA, ** P < 0.01, *** P < 0.001. c, Graphic representation of proteasome cleavage sites, showing differences between constitutive and immunoproteasome activity. d, Heat map of C-terminal cleavages in peptides from MDA-MB231 cells treated with DMSO, Bortezomib (Bort, 50 nM), or the immunoproteasome inhibitor ONX-0914 (ONX, 1 μM). mean ± s.e.m. (n = 3 biological replicates). e, Western blot analysis of PSME3 levels in A549 cells expressing shCTRL or shPSME4, compared to vinculin. f, CFU counts of S. typhimurium from A549 cells infected after pre-treatment with JSH-23 (40 µM) for 2 h. mean ± s.e.m. (n = 3 biological replicates). One-way ANOVA, ns P > 0.05, **** P < 0.0001. g, Representative images of A549 cells expressing shCTRL or shPSME3, treated with IKK16 (1 µM), and infected with RFP- S. typhimurium (magenta). Nuclei are stained with DAPI (blue). h, Bar plots quantifying RFP- S. typhimurium per nucleus. Twelve images per biological replicate. Data are mean ± s.e.m. (n = 3 biological replicates). One-way ANOVA, ns P > 0.05, **** P < 0.0001. Illustrations created in BioRender. Merbl, Y. (2025) https://BioRender.com/x10a923.
