Supplementary Figure 14: Changes in protein disulfide bonds and glutathionylation in human A549 cells upon induction of oxidative stress.

(a) More protein cysteine residues were found in the oxidized forms upon 1 mM diamide treatment for 10 min, including protein disulfide bonds and glutathionylated forms. (b) Of the known disulfide bond-containing proteins, most of disulfide bonds identified in A549 cells agree with the database annotations. (c) A Cytoscape view of the densely connected subnetworks of the proteins that had increased levels of disulfide bonds or glutathionylation after the diamide treatment. The subnetwork with the highest MCODE complex score, defined as the product of the density and the number of nodes in the detected complex, is highlighted and shown on the right. Proteins functioning in mRNA processing are colored red. (d) The three most significantly enriched pathways among the proteins that had increased levels of disulfide bonds or glutathionylation after 1 mM diamide treatment. The p values were calculated using a right-sided hypergeometrical test and corrected for multiple testing using the Benjamini-Hochberg method. (e) Of the proteins that appear to be readily glutathionylated are seven oxidoreductases (red) and two proteins involved in F-actin formation or depolymerization (orange). MGST1: Microsomal glutathione S-transferase 1, CPLX2: Complexin-2, PBK: Lymphokine-activated killer T-cell-originated protein kinase, TXN: Thioredoxin, CPSF6: Cleavage and polyadenylation specificity factor subunit 6, PRDX5: Mitochondrial peroxiredoxin-5, RPLP1: 60S acidic ribosomal protein P1, PRDX3: Mitochondrial thioredoxin-dependent peroxide reductase, DSTN: Actin-depolymerizing factor, PRDX1: Peroxiredoxin-1, CFL1: Cofilin-1, PCBP1: Poly(rC)-binding protein 1, EIF5A: Eukaryotic translation initiation factor 5A-1, AKR1C1: Aldo-keto reductase family 1 member C1, AKR1C3: Aldo-keto reductase family 1 member C3. (f) Motif analysis of glutathionylation sites using pLogo (http://plogo.uconn.edu). The number of aligned foreground and background sequences are 1697 and 12822, respectively. The red horizontal bars correspond to p = 0.05.