Actin chromobody imaging reveals sub-organellar actin dynamics

The actin cytoskeleton plays multiple critical roles in cells, from cell migration to organelle dynamics. The small and transient actin structures regulating organelle dynamics are difficult to detect with fluorescence microscopy, and the limited resolution of fluorescence microscopy makes it difficult to determine whether actin filaments are directly associated with specific membranes. To address these limitations, we developed an approach using fluorescent protein-tagged actin nanobodies targeted to organelle membranes to enable live cell imaging of sub-organellar actin dynamics with unprecedented spatiotemporal resolution.