Biotin Proximity Labeling to Identify Protein-Protein Interactions for Cavin1

Biotin proximity labeling or BioID is a technique used to detect neighboring proteins, including transient and low-affinity interactions in their natural cellular environment. Here I describe the use of BioID in HeLa cells to identify proteins that can potentially interact with cavin1, one of the main components of caveolae. Briefly, the method consists in the transfection of the cells with the fusion constructs containing the promiscuous biotin ligase and cavin1 or control proteins, followed by biotin, cell lysis, affinity isolation of biotinylated proteins, biotin pull-down, and identification of the biotinylated proteins using mass spectrometry.