Fig. 5. ATF-4 and CTH-2 regulate protein persulfidation levels.

a Schematic diagram showing that the thiol group (–SH) of reactive cysteine residues in proteins can undertake various redox states. Sulfenylation (–SOH) can be reversed, particularly efficiently through the intermediate of persulfidation (–SSH), but sulfinylation (–SO₂H) is reversible only within peroxiredoxins and sulfonylation (–SO₃H) is irreversible^35,37. Arrows in orange indicate oxidation processes while those in blue indicate reduction processes. b Representative fluorescent images and quantification (c) showing that ATF-4OE exhibited higher persulfidation levels, while cth-2(mg599) animals exhibited lower global persulfidation levels, compared to WT. Data are represented as Mean ± SEM. n = 3 biological replicates of at least 10 worms per condition. Scale bar = 50 μm. F.I. = fluorescent intensity. P values to WT are unpaired t-test, two-tailed.