Optogenetic and chemical genetic tools for rapid repositioning of vimentin intermediate filaments.
Abstract:
Intermediate filaments (IFs) are a key component of the cytoskeleton, essential for regulating cell mechanics, maintaining nuclear integrity, positioning organelles, and modulating cell signaling. Unlike actin filaments and microtubules, IFs have slower dynamics, and current insights into IF function primarily come from studies using long-term perturbations, such as protein depletion or mutation. Here, we present tools that allow rapid manipulation of vimentin IFs in the whole cytoplasm or within specific subcellular regions by inducibly coupling them to microtubule motors, either pharmacologically or using light. Perinuclear clustering of vimentin had no strong effect on the actin or microtubule organization, cell spreading, and focal adhesions, but reduced cell stiffness. Mitochondria and endoplasmic reticulum sheets were repositioned together with vimentin, whereas lysosomes were only briefly repositioned and rapidly regained their normal distribution. Keratin was displaced along with vimentin in some cell lines but remained intact in others. Our tools help to study the immediate effects of vimentin perturbation and identify direct links of vimentin to other cellular structures.
