Related Experiment Video
Updated: Aug 1, 2026
12:15
In Vitro Polymerization of F-actin on Early Endosomes
Published on: August 28, 2017
Integration of intermediate filaments into cellular organelles
1Program of Cell Biology, European Molecular Biology Laboratory, Germany.
International Review of Cytology
|January 1, 1996
Summary
Intermediate filaments are key cytoskeleton components that interact with cell membranes. This review examines current research to understand the molecular mechanisms of these crucial cytoskeleton-membrane links.
Area of Science:
- Cell Biology
- Cytoskeleton Dynamics
- Molecular Cell Biology
Background:
- Intermediate filaments are essential cytoskeleton components.
- They interact with various membranous organelles, such as desmosomes and the nuclear envelope.
- The precise molecular mechanisms of these interactions remain largely unknown.
Purpose of the Study:
- To review and synthesize existing knowledge on intermediate filament-membrane interactions.
- To formulate working hypotheses regarding the molecular mechanisms involved.
- To bridge the gap between pioneering and recent research in the field.
Main Methods:
- Literature review of pioneering and recent studies.
- Comparative analysis of different intermediate filament systems.
- Synthesis of data to identify common principles and mechanisms.
Main Results:
- Established examples of intermediate filament-membrane attachments (keratin-desmosomes, lamin-nuclear membrane).
- Identification of knowledge gaps in understanding molecular linkages.
- Consolidation of a research base for hypothesis generation.
Conclusions:
- Intermediate filament-membrane interactions are fundamental to cell structure and function.
- Further research is needed to elucidate the specific molecular players and mechanisms.
- This review provides a framework for future investigations into cytoskeleton-organelle connections.
Related Concept Videos
01:33Introduction to the Cytoskeleton
Overview of the Cytoskeleton
The cytoskeleton is a network of protein filaments present within the cell, having three distinct filaments ̶ microfilaments, microtubules, and intermediate filaments. Each has characteristic features that distinguish them, including the dynamics of their assembly and disassembly, mechanical properties, polarity, and the type of molecular motors associated with them. Earlier, they were thought to be present only in eukaryotic cells; however, their homologs were...
The cytoskeleton is a network of protein filaments present within the cell, having three distinct filaments ̶ microfilaments, microtubules, and intermediate filaments. Each has characteristic features that distinguish them, including the dynamics of their assembly and disassembly, mechanical properties, polarity, and the type of molecular motors associated with them. Earlier, they were thought to be present only in eukaryotic cells; however, their homologs were...
01:12Adaptability of Cytoskeletal Filaments
The cytoskeleton is a complex dynamic structure performing varied functions based on cellular requirements. The adaptability of the individual filaments in the cytoskeleton determines their ability to perform various functions within the cell. It can undergo rapid reorganization during processes like cell division or remain stable for several hours as in the interphase. The adaptability of these filaments depends on stringent regulatory mechanisms. The microfilament and microtubules of the...
01:18Assembly of Cytoskeletal Filaments
Cytoskeletal filaments are polymeric forms of smaller protein subunits. However, individual cytoskeletal filaments may easily disassemble or associate with other similar filaments to form rigid structures. Microfilaments, made of actin monomers, rely on actin-binding proteins to form bundles and create networks of individual actin filaments. Microtubules rely on microtubule-associated proteins (MAPs) to form sturdy cylindrical structures. However, the proteins involved in forming complex...
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...
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.
01:35Disassembly 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...