Scientific Director, Institute of Molecular Biology (IMB), Mainz; Professor, Faculty of Biology, University of Mainz.
She was group leader at the Cancer Research UK London Research Institute, Clare Hall Laboratories and Max Planck Institute for Terrestrial Microbiology. Helle was awarded with an ERC advanced grant, EMBO Young investigator, Member of EMBO since 2008 and BioFuture Prize from the German Federal Ministry of Education and Research.
Her research aims at understanding the mechanisms and signals by which the ubiquitin and SUMO systems promote damage tolerance and limit the accumulation of unwanted mutations. DNA damage bypass, also called postreplication repair, is controlled via posttranslational modification of the replication factor PCNA. Whereas monoubiquitylation activates translesion synthesis by damage-tolerant DNA polymerases, polyubiquitylation via lysine 63-linked chains is required for an error-free pathway of damage avoidance possibly involving template switching. PCNA is also sumoylated in a damage-independent manner, which prevents unwanted recombination events during replication and allows the ubiquitin-dependent reactions to proceed upon replication fork stalling.
Using a combination of molecular and cellular biology, biochemistry and classical genetics, her team investigates the factors that influence the choice of bypass pathway and determine the efficiency and accuracy of damage processing, the molecular signals that trigger the each of the modifications at the appropriate time within the cell, the mechanisms by which the ubiquitin and SUMO conjugation factors recognise and modify their substrates, and the coordination of damage bypass with DNA replication, chromatin dynamics and other pathways of genome maintenance.