Cells rely on networks of biopolymers (like Actin filament) that are organized by special proteins to carry out functions such as changing shape, moving, or transporting cargo. RSC Publishing+1 A newer idea is that protein “condensates” (liquid-like droplets of proteins) can join in this organization. MSE professors, Dr. Kim Weirich, Dr. Konstantin Kornev, and their research group, including lead author and MSE grad student Carolyn Feigeles, explored how condensates of the protein FUS interact with pre-formed actin filaments. RSC Publishing
Key findings:
- The FUS condensates stick to bundles of actin filaments and cause them to bundle further. The condensates wrap around the bundles somewhat like how liquid drops spread on fibers. RSC Publishing
- The researchers measured how the condensates spread (for example by looking at the “contact angle” they make with the bundle) and how they merge with other condensates. RSC Publishing
- Importantly, when condensates sit at intersections of actin bundles they create capillary bridges (liquid‐bridge forces) that pull bundles together and remodel the network structure. So instead of just standard protein cross‐linkers doing the bundling, this shows a physical mechanism—capillary forces due to condensates—can reshape the network. RSC Publishing+1
Why this matters:
This work points to a new way cells might organize their cytoskeleton (the “skeleton” inside cells made of filaments like actin) not only via chemical binding-proteins, but also via physical wetting and bridging by condensates. That means network geometry and dynamics could depend on liquid-droplet behavior inside the cell. RSC Publishing
Takeaway:
By showing how protein condensates can drive bundling and network remodeling via capillary forces, the authors broaden our understanding of cellular organization. Imagine droplets of protein acting like glue and liquid bridges between fibers inside the cell—pulling things together and changing the network. It’s a neat intersection of biology and physics.
To read the article click here.
Protein condensates induce biopolymer filament bundling and network remodeling via capillary interactions Carolyn A. Feigeles , Artis Brasovs , Adam Puchalski , Olivia Laukat , Konstantin G. Kornev and Kimberly L. Weirich *
