Microscopy images of biological cells: leading right (green)– Vimentin intermediate filaments in fibroblasts; bottom left (red)– Keratin intermediate filaments in epithelial cells. Credit: top right (green): Ulrike Rölleke.
Göttingen University researchers discover surprising properties of the cytoskeleton.
Many biological cells have a repaired location in an organism. The characteristics of fixed and mobile cells display a number of distinctions, one notable one being the structure of their cytoskeleton.
This structure of protein filaments makes the cells stable, stretchable, and resistant to external forces. In this context, “intermediate filaments” play an important role. Remarkably, 2 various kinds of intermediate filaments are discovered in fixed and mobile cells. Researchers at the University of Göttingen and ETH Zurich have actually prospered in precisely determining and explaining the mechanical residential or commercial properties of the 2 filaments. At the same time, they found parallels with non-biological products. The results have actually been released in the journal Matter.
The researchers used optical tweezers to investigate how the filaments act under tension. The researchers worked out which forces were necessary for the extending and how the various filaments acted when they were extended numerous times.
Microscopy images of biological cells: top right (green)– Vimentin intermediate filaments in fibroblasts; bottom left (red)– Keratin intermediate filaments in epithelial cells. Interestingly, two different types of intermediate filaments are discovered in mobile and stationary cells. The speculative outcomes match computer simulations of molecular interactions: in vimentin filaments, the researchers presume that structures open up, comparable to gels made of several parts; in keratin filaments, they assume that structures shift against each other, as in metals. Both mechanisms explain that the networks of intermediate filaments in the cytoskeleton can be warped very strongly without being damaged.
Remarkably, the two various filaments act in contrasting ways when repeatedly extended: vimentin filaments become softer and keep their length, keratin filaments become longer and retain their stiffness.
The speculative outcomes match computer system simulations of molecular interactions: in vimentin filaments, the researchers assume that structures open up, comparable to gels made of numerous components; in keratin filaments, they presume that structures shift versus each other, as in metals. Both systems describe that the networks of intermediate filaments in the cytoskeleton can be deformed really strongly without being damaged. However, this protective factor is discussed by fundamentally different physical concepts.
” These outcomes extend our understanding of why different cell types have such different mechanical residential or commercial properties,” describes Dr Charlotta Lorenz, first author of the research study. Teacher Sarah Köster, from Göttingen Universitys Institute of X-Ray Physics and leader of the research study, adds: “We can discover from nature and think about the style of new, sustainable and transformable materials whose residential or commercial properties can be chosen or designed to fit the requirements precisely.”
Recommendation: “Keratin filament mechanics and energy dissipation are figured out by metal-like plasticity” by Charlotta Lorenz, Johanna Forsting, Robert W. Style, Stefan Klumpp and Sarah Köster, 22 May 2023, Matter.DOI: 10.1016/ j.matt.2023.04.014.