Subcellular Interactomes Revealed by Merging APEX with Cross-Linking Mass Spectrometry

Anal Chem. 2022 Nov 1;94(43):14878-14888. doi: 10.1021/acs.analchem.2c02116. Epub 2022 Oct 20.

Abstract

Subcellular protein-protein interactions (PPIs) are essential to understanding the mechanism of diverse cellular signaling events and the pathogenesis of diseases. Herein, we report an integrated APEX proximity labeling and chemical cross-linking coupled with mass spectrometry (CXMS) platform named APEX-CXMS for spatially resolved subcellular interactome profiling in a high-throughput manner. APEX proximity labeling rapidly captures subcellular proteomes, and the highly reactive chemical cross-linkers can capture weak and dynamic interactions globally without extra genetic manipulation. APEX-CXMS was first applied to mitochondria and identified 653 pairs of interprotein cross-links. Six pairs of new interactions were selected and verified by coimmunoprecipitation, the mammalian two-hybrid system, and surface plasmon resonance method. Besides, our approach was further applied to the nucleus, capturing 336 pairs of interprotein cross-links with approximately 94% nuclear specificity. APEX-CXMS thus provides a simple, fast, and general alternative to map diverse subcellular PPIs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cross-Linking Reagents / chemistry
  • Mammals*
  • Mass Spectrometry / methods
  • Proteins* / chemistry

Substances

  • Proteins
  • Cross-Linking Reagents