Comprehensive Characterization of Minichromosome Maintenance Complex (MCM) Protein Interactions Using Affinity and Proximity Purifications Coupled to Mass Spectrometry

The
extensive identification of protein–protein interactions
under different conditions is an important challenge to understand
the cellular functions of proteins. Here we use and compare different
approaches including affinity purification and purification by proximity
coupled to mass spectrometry to identify protein complexes. We explore
the complete interactome of the minichromosome maintenance (MCM) complex
by using both approaches for all of the different MCM proteins. Overall,
our analysis identified unique and shared interaction partners and
proteins enriched for distinct biological processes including DNA
replication, DNA repair, and cell cycle regulation. Furthermore, we
mapped the changes in protein interactions of the MCM complex in response
to DNA damage, identifying a new role for this complex in DNA repair.
In summary, we demonstrate the complementarity of these approaches
for the characterization of protein interactions within the MCM complex.