Two different representations of tetra-ubiquitin - a molecular 'tag' used to mark proteins inside cells.

Katrin Rittinger : Molecular Structure of Cell Signalling Laboratory

We are deciphering how proteins within a cell communicate with each other to respond to changes in their environment, such as infection with bacteria and viruses, and finding out how faulty signalling can lead to conditions including immune deficiencies and auto-immune diseases.

Communication within a cell - a process called cell signalling - has to be very tightly regulated to ensure that the cell responds appropriately to any changes. For example, when a cell is infected with bacteria or viruses, it should produce molecules that alert surrounding cells to the danger and provoke an immune response. If this communication breaks down or the signals are overactive then this can have devastating effects, causing conditions such as auto-inflammatory diseases, cancer or degenerative diseases.

A common way of controlling cell signalling is the modification of proteins with small molecules (chemical ‘tags’), which change their behaviour or location within a cell. One such modifier is the small protein ubiquitin that can be attached to other proteins - a process called ubiquitination. Protein ubiquitination regulates many cellular processes including immune responses and DNA damage repair. Defects in the ubiquitination system have been linked to many diseases including cancer and autoimmune diseases.

Because of the central role of protein ubiquitination in health and disease, there is a lot of interest in developing drugs that target this process. We are investigating how cells control protein ubiquitination, providing valuable knowledge to underpin the development of new treatments.