Max Planck Institutes and Experts

Cells contact other cells via precise docking points. Cell migration and immune reactions require a finely tuned attachment and detachment process. Therefore, the contact sites consist of a whole machinery of proteins, in which talin plays a central role. Using cryo-electron microscopy, we were able to show how talin can assume an inactive spherical shape and is thus inaccessible to contact other proteins. These results help to understand the adhesion mechanism and also dysfunctions in disease processes.

Climate extremes, in particular heat waves, droughts, and their combination are inevitably increasing as a result of climate change. But little is known about how these events affect the terrestrial biosphere, which ecosystem functions are severely affected, and what feedbacks this may trigger in the climate system. At the Max Planck Institute for Biogeochemistry we are developing new methods for the detection of extreme events in heterogeneous data streams. Our results show, among other things, how differently various ecosystems can react to extreme events.

Many cancers reprogram cellular metabolism in order to sustain tumour growth. Mitochondria are essential organelles which provide cancer cells with the metabolic flexibility required in challenging environmental conditions. Our recent work has revealed that tumour cells growing in low oxygen or nutrient deprived conditions are able to rewire their mitochondria by degrading specific mitochondrial proteins. We propose that analyzing this mechanism will provide therapeutic targets in hard-to-treat tumours such as pancreatic cancer.

The overexpression of four specific transcription factors allows for reprogramming of somatic cells into induced pluripotent stem cells (iPSCs), which can give rise to all cell types of the adult body. We found that overexpression of one of these factors,  Oct4, causes epigenetic changes that deteriorate the quality of the resultant iPSCs. Excluding Oct4 from the reprogramming cocktail leads to iPSCs with unprecedented developmental potential.

Controlled protein degradation plays a crucial role for the correct progression of cell cycle, signal transduction, gene expression or programmed cell death. In eukaryotes, organisms with a nucleus, a complex machinery of enzymes handles this highly regulated process. Recently, the existence of related enzyme systems has also been found in prokaryotes, organisms without a nucleus. The analysis of these nanomachines provides insight into the evolution of cellular protein degradation and the origin of the eukaryotic degradation machinery.