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Updated: May 27, 2026
14:23
Imaging Intermediate Filaments and Microtubules with 2-dimensional Direct Stochastic Optical Reconstruction Microscopy
Published on: March 6, 2018
Inroads into the structure and function of intermediate filament networks
Robert D Goldman1, Megan M Cleland, S N Prasanna Murthy
1Department of Cell and Molecular Biology, Northwestern University's Feinberg School of Medicine, 303 E. Chicago Avenue, Chicago, IL 60611, USA. r-goldman@northwestern.edu
Journal of Structural Biology
|November 29, 2011
Summary
Intermediate filaments (IFs), a key part of the cell cytoskeleton, are complex due to their large gene family and cell-specific regulation. This review highlights 40 years of research on IF structure and function.
Area of Science:
- Cell Biology
- Biochemistry
- Biophysics
Background:
- Intermediate filaments (IFs) are a major cytoskeletal system in vertebrate cells.
- Their complex structure and function remain incompletely understood.
- This complexity arises from a large gene family with cell- and tissue-specific developmental regulation.
Purpose of the Study:
- To honor Ueli Aebi's contributions to the field.
- To review over 40 years of laboratory research on intermediate filaments.
- To highlight advances in understanding IF structure and function.
Main Methods:
- Decades of laboratory research.
- Analysis of intermediate filament structure and function.
- Collaborative discussions and insights, often gained during outdoor activities.
Main Results:
- Significant advances in understanding the structure and function of intermediate filaments.
- Elucidation of the cell and tissue type-specific regulation of IFs.
- Development of new perspectives on IFs through interdisciplinary collaboration.
Conclusions:
- Intermediate filaments are crucial but complex cytoskeletal components.
- Continued research is essential for a comprehensive understanding of IFs.
- Interdisciplinary collaboration and dedicated research efforts drive scientific progress.
Related Concept Videos
01:19The Structure of Intermediate Filaments
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 filaments...
Intermediate filaments...
01:35Disassembly of Intermediate Filaments
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...
00:57Formation of Intermediate Filaments
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 reported.
01:39Mechanism of Filopodia Formation
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...
01:11Formation of Higher-order Actin Filaments
The polymerization of G-actin monomers into filamentous F-actin is a multi-step process. Once the F-actins are formed, they can bundle together in different arrangements to form higher-order networks and regulate cellular functions. Common examples include the formation of lamellipodia and filopodia at the cell's leading edge by actin reorganization in a migrating cell. The microvilli on the brush border epithelial cells are also formed through the F-actin network.
The high-order actin networks...
The high-order actin networks...
01:31Types of Intermediate Filaments
The intermediate filaments are an essential component of the cytoskeleton. Presently six types of intermediate filament have been identified. Type I and II are acidic and basic keratin proteins. Type III is of mesodermal origin and comprises four proteins: vimentin, desmin, glial fibrillary acidic protein (GFAP), and peripherin. Vimentin is commonly found in mesenchymal cells, desmin in muscle cells, GFAP in astrocytes, while peripherin is found in peripheral nervous system neurons (PNS). Type...