2025 Volume 65 Issue 4 Pages 188-191
In metazoan cells, microtubules (MTs), intermediate filaments (IFs), and actin filaments (AFs) are involved in maintaining cell integrity and regulating cell motility. Unlike MTs and AFs, IFs are nonpolar filaments composed of elongated units. It has been postulated that type 3 IFs and AFs interact directly, which may facilitate the organization of cytoplasmic networks. We observed colocalization between desmin IFs (type 3 IFs in muscle cells) and AFs in cell-sized droplets in vitro via fluorescence microscopy. Direct observation of individual desmin IFs and moving AFs on myosins demonstrated a nematic behavior of AFs along desmin IFs due to loose interactions.
