Membrane-less organelles are intriguing structures that play crucial roles in cellular physiology. In recent years, it has become clear that these organelles are not static entities but rather highly dynamic and regulated compartments within the cell. They can undergo phase separation, forming biomolecular condensates such as liquid-like droplets or solid-like gels.1 To better understand the mechanisms behind the formation and regulation of these organelles, our project focuses on investigating mimics of membrane-less organelles in vitro using photoswitchable-peptide and RNA-containing condensates.
Photoswitchable peptides undergo a geometrical conformation change (E ↔ Z) upon irradiation with specific wavelengths. Using mixtures of our photoswitchable peptide and RNA we can therefore use different wavelengths of light to trigger the coacervation or de-coacervation (disassociation) of the RNA and peptide mixtures. In this project, we use this powerful tool to study in-depth the assembly and regulation of dynamic membrane-less organelles based on RNA-peptide condensates. This study contributes to our understanding of the cellular chemistry of protein-RNA interactions and provides the foundation for potential therapeutic applications that photoswitchable peptides might have in this context.