Scientists Uncover Astonishing Characteristics of the Cytoskeleton at Göttingen University
Visual representation of biological cells: Upper right (green) – Vimentin intermediate filaments in fibroblasts; Lower left (red) – Keratin intermediate filaments in epithelial cells. Scale: 10 µm. Image credit: top right (green): Ulrike Rölleke. bottom left (red): Ruth Meyer.
Researchers at Göttingen University have made a remarkable discovery regarding the cytoskeleton, shedding light on its surprising properties.
Typically, biological cells remain fixed in specific locations within an organism. However, in certain instances, these cells gain mobility, allowing them to traverse the body. Such occurrences arise during processes like wound healing or the unchecked division and spread of cancerous cells. Notably, the structure of the cytoskeleton differs between mobile and stationary cells.
The cytoskeleton’s protein filaments provide stability, elasticity, and resilience against external forces. Within this framework, “intermediate filaments” play a crucial role. Interestingly, mobile and stationary cells contain two distinct types of intermediate filaments. Scientists from the University of Göttingen and ETH Zurich have conducted precise measurements and descriptions of the mechanical properties of these two filaments, uncovering unexpected parallels with non-biological materials. The findings have been published in the journal Matter.
The researchers employed optical tweezers to examine how the filaments respond under tension. They attached the filaments’ ends to minuscule plastic beads, which they manipulated using a laser beam in a controlled manner. By stretching the vimentin and keratin filaments, the two different types under investigation, the scientists determined the necessary forces for stretching and observed how the filaments behaved through multiple rounds of stretching.
Surprisingly, when subjected to repeated stretching, the two filament types exhibit contrasting behavior: vimentin filaments become softer while maintaining their length, whereas keratin filaments become longer while retaining their stiffness.
The experimental results align with computer simulations of molecular interactions: the researchers postulate that vimentin filaments undergo structural openings akin to gels composed of multiple components, while keratin filaments experience internal shifts resembling those in metals. Both mechanisms elucidate how the intermediate filament networks within the cytoskeleton can undergo significant deformation without sustaining damage. However, this protective characteristic arises from fundamentally distinct physical principles.
Dr. Charlotta Lorenz, the study’s lead author, elaborates, “These findings expand our understanding of the varying mechanical properties exhibited by different cell types.” Professor Sarah Köster, the head of Göttingen University’s Institute of X-Ray Physics and the study’s leader, adds, “We can draw inspiration from nature and contemplate the development of novel, sustainable, and adaptable materials, tailored precisely to meet specific requirements.”
Reference: “Keratin filament mechanics and energy dissipation are determined by metal-like plasticity” by Charlotta Lorenz, Johanna Forsting, Robert W. Style, Stefan Klumpp, and Sarah Köster, 22 May 2023, Matter.
Frequently Asked Questions (FAQs) about cytoskeleton properties
What is the cytoskeleton?
The cytoskeleton is a structure of protein filaments found in biological cells that provides stability, stretchability, and resistance to external forces.
What are intermediate filaments?
Intermediate filaments are a type of protein filament within the cytoskeleton that plays an important role in the mechanical properties of cells. Different cell types have different types of intermediate filaments.
What did the researchers discover about the cytoskeleton?
The researchers discovered surprising properties of the cytoskeleton’s intermediate filaments. They found that vimentin filaments become softer when stretched repeatedly, while keratin filaments become longer while maintaining stiffness.
How did the researchers study the filaments?
The scientists used optical tweezers, a tool that utilizes a laser beam, to investigate the behavior of the filaments under tension. They attached the filaments to tiny plastic beads and controlled their movement to stretch them.
How do these findings contribute to materials science?
The findings provide insights into the mechanical properties of the cytoskeleton and offer inspiration for the design of new, sustainable materials that can be tailored to specific requirements.
More about cytoskeleton properties
- University of Göttingen: Göttingen University
- ETH Zurich: ETH Zurich
- Journal Matter: Matter Journal
- Optical Tweezers: Optical Tweezers – Wikipedia