Yosef Gruenbaum: li. This article has been cited by other articles in PMC. Abstract In humans the superfamily of intermediate filament IF proteins is encoded by more than 70 different genes, which are expressed in a cell- and tissue-specific manner. IFs assemble into approximately 10 nm-wide filaments that account for the principal structural elements at the nuclear periphery, nucleoplasm, and cytoplasm. They are also required for organizing the microtubule and microfilament networks. In this review, we focus on the dynamics of IFs and how modifications regulate it.

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Intermediate filaments: structure, dynamics, function, and disease. Google Scholar 4 Herrmann, H. Functional complexity of intermediate filament cytoskeletons: from structure to assembly to gene ablation. Google Scholar 5 Omary, M. Intermediate filament proteins and their associated diseases.

Google Scholar 6 Capell, B. Human laminopathies: nuclei gone genetically awry. Nature Rev. Google Scholar 7 Green, K. Intermediate filament associated proteins.

Protein Chem. Google Scholar 8 Bershadsky, A. Adhesion-dependent cell mechanosensitivity. Cell Dev. Google Scholar 9 Herrmann, H. Intermediate filaments: molecular structure, assembly mechanism, and integration into functionally distinct intracellular scaffolds. Google Scholar 10 Goldman, R. The function of intermediate filaments in cell shape and cytoskeletal integrity.

Cell Biol. The injection of peptides that represent coil 1A of vimentin into fibroblasts leads to the disassembly of IFs, followed by a massive reorganization of the whole cytoskeleton and alterations of cellular shape.

Google Scholar 11 Gruenbaum, Y. The nuclear lamina comes of age. Google Scholar 12 Tzur, Y. Google Scholar 13 Roper, K.

Cell Sci. Google Scholar 14 Wilhelmsen, K. Nesprin-3, a novel outer nuclear membrane protein, associates with the cytoskeletal linker protein plectin.

The outer nuclear membrane protein nesprin-3 is shown to bind to and recruit plectin to the nuclear periphery, suggesting that a continuous connection between the nucleus and the extracellular matrix is mediated with the help of the IF cytoskeleton and the integrin system.


Intermediate filament

Function of intermediate filaments Intermediate filaments are crucial for providing physical support and stabilizing the structure of cells and tissus, enabling them to withstand mechanical stress and tension. A subgroup of intermediate filaments, VIM , has been shown to exhibit different properties when exposed to increasing levels of strain in vitro. Intermediate filaments have also been implicated in cell adhesion and mobility Leduc C et al, Both mutations in genes encoding cytoplasmic intermediate filaments, as well as genes coding for nuclear lamins, have been linked to a number of severe diseases Herrmann H et al, A Gene Ontology GO -based analysis genes localized to the intermediate filament proteome shows enrichment of terms for both biological processes Figure 4a and molecular function Figure 4b that are well in-line with the known functions of the intermediate filaments.


Intermediate filaments: a dynamic network that controls cell mechanics

Accordingly, wildtype cells expressing a vimentin variant unable to polymerize show deficient endoplasmic spreading as well as defects in FA growth. Moreover, treatment of these cells with the calpain inhibitor 1, ALLN, restores FA growth despite the lack of vimentin IFs, but does not restore endoplasmic spreading, implying that vimentin IFs are needed for endoplasm spreading. Consistent with that hypothesis, vimentin IFs are always displaced from FAs when the endoplasm does not spread. Taken together, these and other findings suggest that endoplasmic spreading requires the coalescence of vimentin IFs at force-bearing FAs [ ]. Conclusions It is clear that IFs are essential components of cell architecture.


Intermediate filaments: from cell architecture to nanomechanics.

Structure of intermediate filament The structure of proteins that form intermediate filaments IF was first predicted by computerized analysis of the amino acid sequence of a human epidermal keratin derived from cloned cDNAs. This name reflects the fact that the structure of each protein is helical, and the intertwined pair is also a helical structure. Structural analysis of a pair of keratins shows that the two proteins that form the coiled-coil bind by hydrophobic. Identical ULFs associate laterally into staggered, antiparallel , soluble tetramers, which associate head-to-tail into protofilaments that pair up laterally into protofibrils, four of which wind together into an intermediate filament. The N-terminus and the C-terminus of IF proteins are non-alpha-helical regions and show wide variation in their lengths and sequences across IF families.

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