FIGURE 1.

H₂O₂-induced thiol modifications and scavenging activities in the nucleus. H₂O₂ accumulating in the nucleus can be detoxified by a NTR/TRX/PRX system. While many other H₂O₂ detoxification enzymes are active in plants (e.g., catalases and ascorbate peroxidases), their presence in the nucleus is not demonstrated yet. They are not represented here. H₂O₂ can oxidize thiol residues in protein. Sulfenic acid reacts with GSH, NO or with adjacent thiol residues. Putative nuclear proteins prone to S-glutathionylated, S-nitrosylated, or disulfide bonds formation have been identified by proteomic and biochemical approaches (see Supplementary Table 1; Delorme-Hinoux et al., 2016; Pérez-Pérez et al., 2017). S-glutathionylated, S-nitrosylated, or intra/intermolecular disulfide bonds can be reduced by NTR/TRX, GR/GSH/GRX, or GSNOR. NTR, NADPH-dependent thioredoxin reductase; TRX, thioredoxin; GR, glutathione reductase; GRX, glutaredoxin; PRX, peroxiredoxin; GSNOR, S-nitrosoglutathione reductase; GSH, glutathione; NO, nitric oxide; H₂O₂, hydrogen peroxide.