Chemoproteomic Profiling Maps Zinc-Dependent Cysteine Reactivity

Chem Res Toxicol. 2024 Apr 15;37(4):620-632. doi: 10.1021/acs.chemrestox.3c00416. Epub 2024 Mar 14.

Abstract

As a vital micronutrient, zinc is integral to the structure, function, and signaling networks of diverse proteins. Dysregulated zinc levels, due to either excess intake or deficiency, are associated with a spectrum of health disorders. In this context, understanding zinc-regulated biological processes at the molecular level holds significant relevance to public health and clinical practice. Identifying and characterizing zinc-regulated proteins in their diverse proteoforms, however, remain a difficult task in advancing zinc biology. Herein, we address this challenge by developing a quantitative chemical proteomics platform that globally profiles the reactivities of proteinaceous cysteines upon cellular zinc depletion. Exploiting a protein-conjugated resin for the selective removal of Zn2+ from culture media, we identify an array of zinc-sensitive cysteines on proteins with diverse functions based on their increased reactivity upon zinc depletion. Notably, we find that zinc regulates the enzymatic activities, post-translational modifications, and subcellular distributions of selected target proteins such as peroxiredoxin 6 (PRDX6), platelet-activating factor acetylhydrolase IB subunit alpha1 (PAFAH1B3), and phosphoglycerate kinase (PGK1).

MeSH terms

  • Cysteine* / chemistry
  • Proteins / chemistry
  • Zinc* / metabolism

Substances

  • Cysteine
  • Zinc
  • Proteins