Mitochondria are essential organelles found in every eukaryotic cell, required to convert food into usable energy. The mitochondrial oxidative phosphorylation (OXPHOS), which produces the majority of cellular energy in the form of ATP, is controlled by two distinct genomes: the nuclear and the mitochondrial genome (mtDNA). Mutations in mitochondrial genes encoded by either genome could cause mitochondrial disorders, and have emerged as a key factor in a myriad of “common” diseases, including Parkinson’s and Alzheimer’s Disease, Type 2 Diabetes, and are strongly linked to the ageing process. Despite all this, it is surprising that our understanding of the mechanisms governing the mitochondrial gene expression, its reliance on the complex nature of dual genome control and associated pathologies remains superficial, with therapeutic interventions largely unexplored. Remarkably, mitochondria are now also viewed as main regulators of signal transduction. Within the last few years, multiple mitochondria-centric signalling mechanisms have been proposed, including release of multiple metabolites, and the scaffolding of signalling complexes on the outer mitochondrial membrane. It has also been shown that mitochondrial dysfunction causes induction of stress responses, bolstering the idea that mitochondria communicate their fitness to the rest of the cell. Studies in this area are not only of basic scientific interest, but may also provide new avenues towards treatment of mitochondrial dysfunction in a variety of human diseases and ageing.

The group mainly uses in vivo transgenic mouse models and also the roundworm Caenorhabditis elegans to tackle specific questions of mitochondrial pathophysiology. Many of the transgenic mice models are developed within the group. The group relies mainly on various molecular biology techniques to understand the complex signalling pathways, many of which are specifically developed to understand the mitochondrial physiology. To tackle complex molecular mechanisms of specific processes in details, we often turn to mammalian cell-based models and different biochemical approaches. As one of the main aims is to understand the consequences of energy depletion in cells and the organism as a whole, the lab has established many different bioenergetic approaches in vitro and in vivo, and this expertise is provided to the Cologne research community.