MPIB Director receives 2.48 Million Euros from the EU

In a cell, a protein can mediate different functions. To achieve this, proteins can be tailored for specific tasks by modifications. Stefan Jentsch and his team at the Max Planck Institute of Biochemistry in Martinsried near Munich, Germany, are studying how proteins are modified in cells to achieve these different tasks. For his project, Stefan Jentsch has now been awarded an Advanced Grant of the European Research Council (ERC). He will use the 2.48 Million Euros to investigate how the protein marker SUMO modifies entire groups of proteins. The ERC Advanced Grants allow exceptional established research leaders to pursue ground-breaking, high-risk projects that open new directions in their respective research fields.

Posttranslational modification (PTM) of proteins by ubiquitin family proteins is of fundamental importance for cellular function, regulation and development. Ubiquitylation typically targets individual proteins, and high selectivity is achieved by a plethora of ubiquitin-conjugating enzymes and ligases. Much less is known regarding how modification by the ubiquitin-related protein SUMO influences the function of substrates and how specificity is provided. Surprisingly, although SUMOylation affects roughly 10% of all yeast proteins, only very few enzymes participate in the pathway. Moreover, although SUMOylation is essential for viability, mutants defective in SUMOylation of individual substrates usually lack deleterious phenotypes. Stefan Jentsch’s group recently solved this puzzle as they found that SUMOylation frequently targets protein groups (“protein group modification”) rather than individual substrates; single modifications are often redundant or additive as SUMO functions as intermolecular “glue”, thereby stabilizing protein complexes. Hence, the traditional view that a single PTM on a given protein mediates a specific function does not seem to apply for many SUMO modifications. Entirely divergent from previous approaches the group will focus for the first time specifically on protein group SUMOylation and its special requirements for specificity, induction and termination. Initially found for proteins of homologous recombination and nucleotide excision DNA repair, the Jentsch group will expand the concept of protein group SUMOylation with a focus on pathways relevant for cellular regulation and which are of medical importance.