Related Experiment Video
Updated: Jul 5, 2025
08:00
DNA Nanotubes as a Versatile Tool to Study Semiflexible Polymers
Published on: October 25, 2017
6.9K
Inference of the force pattern acting on a semiflexible filament from shape analysis.
Julieta Wenger1, Azul Brigante1, Agustina B Fernández Casafuz2
1Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Física, C1428EGA Buenos Aires, Argentina.
Physical Review. E
|January 20, 2024
Summary
We developed a new method to measure forces on cytoskeleton filaments. This technique uses curvature analysis to pinpoint the location and strength of active forces on single filaments.
Area of Science:
- Cellular Biophysics
- Biomechanics
- Soft Matter Physics
Background:
- Studying forces on cytoskeleton filaments requires noninvasive methods.
- Existing techniques struggle to analyze deformations in natural cellular environments.
Purpose of the Study:
- To present a practical, noninvasive method for analyzing forces on semiflexible filaments.
- To enable exploration of single filament deformation in vivo.
Main Methods:
- Solving the hydrodynamic beam equation with transverse forces.
- Analyzing discontinuities in the derivative of local curvature.
- Utilizing kymographs of curvature to visualize force dynamics.
Main Results:
- Discontinuities in curvature derivative precisely locate applied transverse forces.
- Curvature kymographs reveal temporal force behavior.
- Method validated through numerical simulations of microtubule deformation.
Conclusions:
- The proposed method accurately identifies and quantifies forces on individual filaments.
- This technique offers a valuable tool for understanding cytoskeletal dynamics.
- Enables new insights into intracellular active forces.
Related Concept Videos
01:17Studying the Cytoskeleton
6.2K
The cytoskeletal architecture can be studied using different microscopic and biochemical techniques. Electron microscopy was instrumental in discovering the cytoskeletal architecture around the 1960s, which allowed obtaining structural information at a high-resolution level. However, the sample preparation procedure often limits this ability in biological samples. Several protocols have been developed over the years to optimize sample preparation. In one of the protocols known as rotary...
6.2K
01:35Disassembly of Intermediate Filaments
2.1K
Intermediate filaments (IFs) do not undergo spontaneous disassembly. Enzymes, kinases, and phosphatases add and remove phosphates from specific sites to regulate their disassembly. The IF concentration in the cytoplasm also regulates the disassembly. If the concentration crosses a threshold, it activates the protein kinases in the vicinity, allowing the phosphorylation of IFs.
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
2.1K
00:57Formation of Intermediate Filaments
3.1K
Intermediate filaments are cytoskeletal proteins with higher tensile strength and flexibility than microfilaments and microtubules. Unlike the other two cytoskeletal proteins, intermediate filament formation lacks the enzymatic activity to hydrolyze nucleotides like ATP and GTP to generate energy for polymerization. Therefore, the formation of intermediate filaments is multistep self-assembly. The involvement of any accessory proteins in intermediate filament formation has not yet been...
3.1K
01:14Generation of Straight or Branched Actin Filaments
2.9K
The straight or branched structure formation of actin filaments is controlled by nucleating proteins such as the formins and Arp2/3 complex. Formin-mediated assembly results in straight filaments, whereas Arp2/3 protein complex-mediated assembly results in branched actin filaments.
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
2.9K
01:19The Structure of Intermediate Filaments
4.0K
The intermediate filaments are one of three widely studied cytoskeletal filaments. They are so named as their diameter (10 nm) is in between that of microfilaments (7 nm) and the microtubules (25 nm). These filaments are highly stable and can remain intact when exposed to high salt concentrations and detergents. These filaments are responsible for providing stability and mechanical support to the cells. They also help in cell adhesion and maintaining tissue integrity.
Intermediate...
Intermediate...
4.0K
01:39Mechanism of Filopodia Formation
2.3K
Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
2.3K