Identifying nuclear protein-protein interactions using GFP affinity purification and SILAC-based quantitative mass spectrometry.

Many cellular proteins assemble into macromolecular protein complexes. Therefore, identifying protein-protein interactions (PPIs) is essential to gain insight into the function of proteins. Recently established quantitative mass spectrometry-based techniques have significantly improved the unbiased search for PPIs. In this chapter, we describe a single-step GFP affinity purification method combined with SILAC-based quantitative mass spectrometry that can be used to identify nuclear PPIs in mammalian cells.