Proximity-dependent biotinylation technologies are versatile tools to unravel interactions between macromolecules in vivo. The approach relies on the inducible activity of enzymes (biotin ligases or peroxidases) that promiscuously biotinylate macromolecules within a short range (10-20 nm). For this presentation, typically, the enzyme (biotin ligase) is fused to a protein of interest and expressed in living cells (fungi, plants) to biotinylate the amino acids of binding partners in proximity. The biotinylated molecules can then be easily affinity purified under denaturing conditions and analyzed by mass spectrometry. This approach has numerous advantages over the standard affinity purification strategies, such as immunoprecipitation and GST pull-downs, etc., including the identification of transient interactions as well as interactions among low-expressed molecules.

This presentation will give examples of the use of BioID in both plants and fungi (F. graminearum) to identify effectors and their targets.