Maintenance of genome integrity relies on intricate cross-talks between DNA associated machineries, chromatin factors and signaling pathways regulated through versatile protein-protein interactions. Understanding the molecular logic underlying these interactions requires that competitive and synergistic associations be uncovered at different scales, from the atomic to the cellular one. We have been particularly interested in a class of proteins, called assembly chaperones which are involved in the formation of large macromolecular assemblies. As an example, we showed how Asf1, a central chaperone of histones H3 and H4, act in a synergistic manner with the Mcm2 helicase to coordinate the assembly and disassembly of nucleosomes at the replication fork. Other binding surfaces on Asf1 were also characterized revealing how other partners such as Rad53 (involved in signaling DNA damages), HirA (transcription) or CAF1 (replication) interact in a competitive manner with Asf1. These interactions take place in different epigenetic context and we are currently investigating how this context is influencing the network of interactions around Asf1.