Proximity Labelling Assays to Detect Protein Interactions in Cells

Protein functionality is intricately linked to their assemblies and interactions, which exhibit complex spatial and temporal organization within cells. To better understand protein function, it's often beneficial to analyze proteins alongside their neighboring molecules. However, protein-protein interactions occur across a wide spectrum of affinity and duration. Proximity labeling offers an alternative approach by targeting proteins near the molecule of interest, regardless of their binding affinity. We will review current proximity labeling techniques and outline a protocol for antibody-directed tag deposition in fixed and permeabilized cell lines and primary human tissue samples.