Every cell contains millions of protein molecules. Some of them have the ability to phase-separate to form non-membrane-bound compartments, called biomolecular condensates, inside a cell. It has long been assumed that there was no further structure underlying these condensates, only solution-soluble proteins.
A research group led by Rohit Pappu, PhD, the Gene K. Beare Distinguished Professor of biomedical engineering in the McKelvey School of Engineering at Washington University in St. Louis, and Anthony Hyman, director at the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) in Dresden, Germany, uncovered that there is, in fact, relevant structure underlying condensates.
The finding, a collaboration with scientists at the University of Cambridge, Heinrich Heine University Düsseldorf and Technische Universität Dresden, was published July 5, 2022, in the Proceedings of the National Academy of Sciences.
The team found proteins formed dynamic structures at concentrations too low to form condensates. “Because of specific interactions, you can make lots of small ‘clusters,’” Pappu said. “The clusters have structures, and the structures encode function.”