Mining proteomes for zinc finger persulfidation

Hydrogen sulfide (H₂S) is an endogenous gasotransmitter that signals via persulfidation. There is evidence that the cysteine residues of certain zinc finger (ZF) proteins, a common type of cysteine rich protein, are modified to persulfides by H₂S. To determine how frequently ZF persulfidation occurs in cells and identify the types of ZFs that are persulfidated, persulfide specific proteomics data were evaluated. 22 datasets from 16 studies were analyzed via a meta-analysis approach. Persulfidated ZFs were identified in a range of eukaryotic species, including Homo sapiens, Mus musculus, Rattus norvegicus, Arabidopsis thaliana, and Emiliania huxley (single-celled phytoplankton). The types of ZFs identified for each species encompassed all three common ZF ligand sets (4-cysteine, 3-cysteine-1-histidine, and 2-cysteine-2-hisitidine), indicating that persulfidation of ZFs is broad. Overlap analysis between different species identified several common ZFs. GO and KEGG analysis identified pathway enrichment for ubiquitin-dependent protein catabolic process and viral carcinogenesis. These collective findings support ZF persulfidation as a wide-ranging PTM that impacts all classes of ZFs.