Biological polymer aggregates play an essential role in cellular function. They also have medical relevance as liquid droplets formed by phase separation can be intermediates in the formation of solid protein aggregates that play crucial pathological roles in age-associated diseases, e.g. Alzheimer’s disease. Recent experiments suggest that the solidification of protein condensates is mediated by the condensate surface. Theoretical modeling of phase separation in biological (and other) systems is possible via field-theoretical models, which have contributed significantly to our understanding of such processes. They also allow for a derivation of classical nucleation theory, which describes how a system switches from a metastable to a stable phase. Such studies are currently mostly restricted to very simple nucleation scenarios and have in particular not addressed the solidification scenario relevant for neurodegenerative aging diseases such as Alzheimer’s disease, frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) – see e.g. CRC 1551 projects R02 (PIs Kremer/Kukharenko/Ulrich), R04 (PIs Landfester/Methner/Weil), R08 (PIs Dormann/Stelzl), and R13 (PIs Andrade/Dormann/Walther).
Johannes Gutenberg-Universität Mainz