Human cells have compartments, each with different functions. These different functions mainly arise because each compartment contains a different set of proteins. When some proteins end up in the wrong compartment of the cell, this can cause disease, as the cell cannot function properly any more. Proteins themselves are molecular machines composed of amino acids, connected to each other via the protein backbone, a single chemical structure. Some of these amino acids can be modified by the cell, which changes how the protein behaves, for example the proteins it interacts with, or the cellular compartment it prefers. In this project, we investigate i) the modifications proteins have in different cellular compartments, ii) how these proteins interact with each other based on their modifications, and iii) how this affects the way these proteins behave. This way, we hope to illuminate what makes proteins move to, or even between, certain cellular compartments, and how that can cause disease.