A novel technique for designing and constructing protein droplets within cells

In living cells, biomolecules such as proteins and RNAs assemble into liquid-like droplets, which range in size from several hundred nanometers to several micrometers. Recent studies have revealed that various proteins are capable of forming droplets, but the mechanisms underlying their formation and their physiological significance remain largely unknown. In this study, Dr. Miki's group developed a peptide tag method to easily and artificially construct these mysterious droplets within cells. In detail, they developed the YK peptide that can reversibly assemble and disassemble. The YK peptide is an artificial peptide consisting of 7 to 15 amino acid residues with an alternating sequence of tyrosine (Y) and lysine (K). When YK peptides were fused as tags to the green fluorescent protein (sfGFP), the resulting YK-sfGFP formed droplets within cells. Furthermore, by adjusting the length of the YK peptide chain, the fluidity of the droplets could be controlled. The group also succeeded in constructing multi-component droplets in cells by tagging multiple proteins with the YK peptide. Using this technique, the research group artificially constructed Nck1/N-WASP droplets, which are involved in actin polymerization, within cells and clarified the relationship between their fluidity and function.

Papers

Journal: Nature Communications

Title: De novo designed YK peptides forming reversible amyloid for synthetic protein condensates in mammalian cells

Authors: T. Miki, M. Hashimoto, H. Takahashi, M. Shimizu, S. Nakayama, T. Furuta and H. Mihara

DOI: 10.1038/s41467-024-52708-5