Live-Cell Microscopy Reveals How Cell Movement is Driven
In science, it’s difficult to predict where the next discovery will emerge. While researchers hope that their grant-funded research will be fruitful, sometimes impactful findings can arise from seemingly unlikely source—which is what investigators at the Woods Hole Marine Biological Laboratory (MBL) recently encountered. Two new studies, which began as a student project in the MBL Physiology Course and were developed in the MBL Whitman Center, show how cells respond to internal forces when they orient, gain traction, and migrate in a specific direction.
The findings from the new studies were published recently in Proceedings of the National Academy of Sciences (PNAS), in an article entitled “Actin Retrograde Flow Actively Aligns and Orients Ligand-Engaged Integrins in Focal Adhesions,” and Nature Communications, in an article entitled “Direction of Actin Flow Dictates Integrin LFA-1 Orientation during Leukocyte Migration.”
Both papers focused on the activation of integrins—proteins that allow cells to attach to their external environment and respond to signals coming from other cells. Integrins are transmembrane proteins that often conduct extracellular signals internally, causing structural proteins to react in numerous ways. Using the microscope invented at the MBL, the researchers showed that when integrins unfurl from the cell surface and bind extracellularly, they simultaneously align in the same direction as a force inside the cell (actin retrograde flow).