Laboratory Andrea Pichler
Posttranslational protein modifications are powerful tools to reversibly modulate protein function. They allow dynamic control of cellular processes like transcription, DNA repair, cell cycle progression or meiosis without the need of de novo protein synthesis. Besides phosphorylation, methylation or acetylation, the attachment of ubiquitin and SUMO (small ubiquitin related modifier) are amongst the most frequently used reversible modifications.
SUMO is a small protein that regulates protein functions like stability, activity, intracellular localization etc. The covalent attachment of SUMO to its substrate, called sumoylation, is essential for viability in most organisms. Sumoylation is executed by the hierarchical action of E1, E2 and E3 enzymes that results in mono- or multi-sumoylation of a target protein or attachment of a SUMO chain (Figure 1). Deregulation of this system is implicated in various diseases ranging from diverse types of cancer to several neuropathological diseases. We aim to understand the molecular mechanisms of how conjugation of SUMO is regulated. In our studies, we put strong emphasis on biochemical approaches in combination with general cell biology to gain novel mechanistic insights in the powerful complexity of such regulatory SUMO enzymes.