PhD defence L. (Lennart) van der Wal

Brief summary of the doctoral thesis:

Human bodies are made up of billions of cells, which in turn are very small living entities which can be compared to small factories. These factories use very small machines, in the form of proteins, to stay alive and perform the various functions necessary for both the human body and the all the cells that make up the human body. My research has focused on the manner by which the small machines are targeted for removal, by putting on a modification known as ubiquitin. This can be likened to a label being put on the machine. The final decision whether a machine labeled for removal will definitely be removed is made at the 'recycling machine', or proteasome, which has the ability to remove the destruction label, either to recycle the machine or to save the machine. The process of removing the label, which is performed by ‘deubiquitylating enzymes’ is what we are interested in. How is the decision to either recycle or save the machine made, and which of the multiple deubiquitylating enzymes has what particular role? 
In order to answer these questions and more, we make use of the mass spectrometer, which we can use to detect which machines have the destruction label under different conditions. We also investigated how to better detect these labels using the mass spectrometer and developed other methods for the mass spectrometer to accurately look at the amount of proteins in the cells.