Kai Simons

Robert Koch Gold Medal 2016

Professor Kai Simons receives the Robert Koch Medal in Gold for his impressive lifetime achievements, which took him from Finland via the USA to Heidelberg and to the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden. He is an expert for cell membranes, those wafer-thin membranes made of a double layer of fat molecules (“lipids”) which surround each cell of the human body. It was long thought that these membranes were only a largely uniform fluid matrix. Thanks to Kai Simons, it has been possible to clearly demonstrate the great dynamic and wide range of functions of lipid membrane systems. He discovered island-like structures in the lipid bilayer of cell membranes, which reminded him of the log rafts of Finnish lumberjacks drifting downstream – hence the name “lipid rafts”. However, in fact these nanodomains are dynamic. They fluctuate in size and can be clustered to form liquid platforms that play a significant role in signal transduction and many other membrane processes.

The lipid raft model is linked to new therapy approaches, for example in neurological diseases such as Alzheimer’s, in which malfunctions in lipid rafts play a role. Kai Simons also found clear evidence that many viruses – including influenza, Ebola, measles and HI viruses – use lipid rafts to invade their host cells or to leave them again, by encasing themselves with rafts from the cell membrane.