OHSU study uncovers internal cell 'trade winds' that drive movement and repair

Scientists at Oregon Health and Science University have uncovered a system of internal fluid flows that push essential proteins to the front of cells. The discovery, published in Nature Communications, shows that cells actively generate targeted streams rather than relying solely on random diffusion for protein transport. Researchers describe the mechanism as critical to cell migration, cancer spread and wound healing. The finding originated from an unexpected observation during a neurobiology course at the Marine Biological Laboratory, according to co-corresponding authors Catherine Galbraith and James Galbraith. The Galbraiths, associate professors in the OHSU Biomedical Engineering Department and investigators in the OHSU Knight Cancer Institute, used laser techniques to track proteins inside living cells. A second dark line appeared at the leading edge, revealing a wave of soluble actin being directed forward by the flows. Experiments showed the cells create directional currents, compared to atmospheric rivers, inside a specialized compartment at the front separated by an actin-myosin condensate barrier. The nonspecific flows sweep up many types of proteins at once to support protrusion, adhesion and shape changes needed for movement, immune response and tissue repair. The Galbraiths said the mechanism may explain why certain cancer cells migrate aggressively. The project drew on collaborators at Janelia Research Campus and received support from the National Institute of General Medical Sciences and other organizations.