Question

You performed a co-immunoprecipitation experiment to identify cellular proteins associated with protein X. For the experiment, you used antibodies against protein X that were immobilized on beads. You incubated these beads with cell lysates from either wildtype cells or cells lacking the gene encoding protein Y. After washing and eluting the bound protein off the beads, you separated each bound and unbound fraction by SDS-PAGE. Finally, you performed immunoblotting using antibodies against either protein Y or protein Z. The results of the Western blots are presented in the following schematic drawings. According to these results, do you think protein Y enhances (E) or inhibits (I) binding of protein X to protein Z?

Answer 1

Protein Y enhances the binding of Z to X.