Abstract

Cells and tissues in our body are challenged every day with new environmental situations. For example, sunburn damages your DNA in the respective skin cells and bacteria or viruses try to exploit your body to replicate themselves. Cells have evolved multiple specialised ways to sense these stresses and form it into a signal in order to avoid further damage and alert surrounding cells. They do so through complex signalling cascades, whose components are present within all cells and are only activated upon stimulation to stress. This activation is mediated and amplified mostly by protein modifications such as the attachment of a small chemical group (e.g. a phosphate) and/or the attachment of small proteins. The most prominent and most versatile member of protein attachment is ubiquitin. We are only just beginning to appreciate the subtlety of this modification since ubiquitin can itself be modified by another ubiquitin molecule on eight different attachment points. This results in the formation of ubiquitin chains of different linkage types, all of which, form different signals being generated, read and disassembled by specialised proteins. Compared to the rather simple binary code used in IT or even the 4-letter code used in DNA , the ubiquitin code seems therefore to be much more complex. The talk will highlight this complexity by explaining the roles of ubiquitin within the inflammatory TNF /NFB pathway, thereby including our latest finding of a new NFB regulator that disassembles only one chain type.