Practice question

Protein-protein interactions are commonly examined using co-immunoprecipitation followed by electrophoretic detection. After precipitating bait protein with specific antibody bound to beads, associated partners co-precipitate, are eluted, resolved by SDS-PAGE, transferred to membrane and identified by Western blotting with antibodies against suspected interactors. Polymerase chain reaction amplifies DNA, Northern blot detects RNA transcripts, and electrophoretic mobility shift assay detects DNA-protein complexes, not protein-protein binding. Coupled with far-Western, pull-down or crosslinking approaches, Western blot provides sensitive readout for such interaction networks in signal transduction research.