Addition of electrophilic lipids to actin alters filament structure

2006 ◽  
Vol 349 (4) ◽  
pp. 1387-1393 ◽  
Author(s):  
Javier Gayarre ◽  
David Sánchez ◽  
Francisco J. Sánchez-Gómez ◽  
María C. Terrón ◽  
Oscar Llorca ◽  
...  
Keyword(s):  
Filament Structure ◽  
Electrophilic Lipids

The Hierarchic Order of Intermediate Filament Structure and Assembly

1985 ◽  
Vol 43 ◽  
pp. 722-725
Author(s):  
U. Aebi ◽  
E.C. Glavaris ◽  
R. Eichner
Keyword(s):  
Tissue Specificity ◽  
Structural Model ◽  
Eukaryotic Cells ◽  
Cdna Sequencing ◽  
Filament Structure ◽  
Keratin Filaments ◽  
Isoelectric Points ◽  
Immunological Crossreactivity

Five different classes of intermediate-sized filaments (IFs) have been identified in differentiated eukaryotic cells: vimentin in mesenchymal cells, desmin in muscle cells, neurofilaments in nerve cells, glial filaments in glial cells and keratin filaments in epithelial cells. Despite their tissue specificity, all IFs share several common attributes, including immunological crossreactivity, similar morphology (e.g. about 10 nm diameter - hence ‘10-nm filaments’) and the ability to reassemble in vitro from denatured subunits into filaments virtually indistinguishable from those observed in vivo. Further more, despite their proteinchemical heterogeneity (their MWs range from 40 kDa to 200 kDa and their isoelectric points from about 5 to 8), protein and cDNA sequencing of several IF polypeptides (for refs, see 1,2) have provided the framework for a common structural model of all IF subunits.

Modeling of the Fine Filament Structure of Quiescent Solar Prominences

2017 ◽  
Vol 57 (8) ◽  
pp. 1018-1022 ◽  
Author(s):  
O. A. Korolkova ◽  
A. A. Solov’ev
Keyword(s):  
Fine Filament ◽  
Solar Prominences ◽  
Filament Structure

scholarly journals αE-catenin actin-binding domain alters actin filament conformation and regulates binding of nucleation and disassembly factors

2013 ◽  
Vol 24 (23) ◽  
pp. 3710-3720 ◽  
Author(s):  
Scott D. Hansen ◽  
Adam V. Kwiatkowski ◽  
Chung-Yueh Ouyang ◽  
HongJun Liu ◽  
Sabine Pokutta ◽  
...  
Keyword(s):  
Actin Filament ◽  
Actin Filaments ◽  
Binding Domain ◽  
Actin Binding ◽  
Filamentous Actin ◽  
Filament Structure ◽  
Actin Binding Domain ◽  
Filament Bundles ◽  
Underlying Mechanisms ◽  
Cell Cell

The actin-binding protein αE-catenin may contribute to transitions between cell migration and cell–cell adhesion that depend on remodeling the actin cytoskeleton, but the underlying mechanisms are unknown. We show that the αE-catenin actin-binding domain (ABD) binds cooperatively to individual actin filaments and that binding is accompanied by a conformational change in the actin protomer that affects filament structure. αE-catenin ABD binding limits barbed-end growth, especially in actin filament bundles. αE-catenin ABD inhibits actin filament branching by the Arp2/3 complex and severing by cofilin, both of which contact regions of the actin protomer that are structurally altered by αE-catenin ABD binding. In epithelial cells, there is little correlation between the distribution of αE-catenin and the Arp2/3 complex at developing cell–cell contacts. Our results indicate that αE-catenin binding to filamentous actin favors assembly of unbranched filament bundles that are protected from severing over more dynamic, branched filament arrays.

The beaded filament of the eye lens: an unexpected key to intermediate filament structure and function

1996 ◽  
Vol 6 (4) ◽  
pp. 123-126 ◽  
Author(s):  
Roy A. Quinlan ◽  
Jane M. Carte ◽  
Aileen Sandilands ◽  
Alan R. Prescott
Keyword(s):  
Intermediate Filament ◽  
Structure And Function ◽  
Eye Lens ◽  
Filament Structure ◽  
And Function

scholarly journals Molecular interactions in paracrystals of a fragment corresponding to the alpha-helical coiled-coil rod portion of glial fibrillary acidic protein: evidence for an antiparallel packing of molecules and polymorphism related to intermediate filament structure.

1989 ◽  
Vol 109 (1) ◽  
pp. 225-234 ◽  
Author(s):  
M Stewart ◽  
R A Quinlan ◽  
R D Moir
Keyword(s):  
Glial Fibrillary Acidic Protein ◽  
Molecular Interactions ◽  
Divalent Cations ◽  
Coiled Coil ◽  
Unit Cell ◽  
Acidic Protein ◽  
Filament Structure ◽  
Solution Studies ◽  
Dyad Symmetry ◽  
Fundamental Pattern

We have expressed in Escherichia coli a fragment of c-DNA that broadly corresponds to the alpha-helical coiled-coil rod section of glial fibrillary acidic protein (GFAP) and have used the resultant protein to prepare paracrystals in which molecular interactions can be investigated. An engineered fragment of mouse GFAP c-DNA was inserted into a modified version of the E. coli expression vector pLcII, from which large quantities of a lambda cII-GFAP rod fusion protein were prepared. A protein fragment corresponding to the GFAP rod was then obtained by proteolysis with thrombin. Paracrystals of this material were produced using divalent cations (Mg, Ca, Ba) in the presence of a chaotrophic agent such as thiocyanate. These paracrystals showed a number of polymorphic patterns that were based on a fundamental pattern that had dyad symmetry and an axial repeat of 57 nm. Analysis of both positive and negative staining patterns showed that this fundamental pattern was consistent with a unit cell containing two 48-nm-long molecules in an antiparallel arrangement with their NH2 termini overlapping by approximately 34 nm. More complicated patterns were produced by stacking the fundamental pattern with staggers of approximately 1/5, 2/5, and 1/2 the axial repeat. The molecular packing the unit cell was consistent with a range of solution studies on intermediate filaments that have indicated that a molecular dimer (i.e., a tetramer containing four chains or two coiled-coil molecules) is an intermediate in filament assembly. Moreover, these paracrystals allow the molecular interactions involved in the tetramer to be investigated in some detail.

scholarly journals Evolution of polymer formation within the actin superfamily

2017 ◽  
Vol 28 (19) ◽  
pp. 2461-2469 ◽  
Author(s):  
Patrick R. Stoddard ◽  
Tom A. Williams ◽  
Ethan Garner ◽  
Buzz Baum
Keyword(s):  
Convergent Evolution ◽  
Atp Hydrolysis ◽  
Linear Polymers ◽  
Related Protein ◽  
Protein Families ◽  
Structure And Dynamics ◽  
Polymer Formation ◽  
Filament Structure ◽  
Related Proteins ◽  
Actin Superfamily

While many are familiar with actin as a well-conserved component of the eukaryotic cytoskeleton, it is less often appreciated that actin is a member of a large superfamily of structurally related protein families found throughout the tree of life. Actin-related proteins include chaperones, carbohydrate kinases, and other enzymes, as well as a staggeringly diverse set of proteins that use the energy from ATP hydrolysis to form dynamic, linear polymers. Despite differing widely from one another in filament structure and dynamics, these polymers play important roles in ordering cell space in bacteria, archaea, and eukaryotes. It is not known whether these polymers descended from a single ancestral polymer or arose multiple times by convergent evolution from monomeric actin-like proteins. In this work, we provide an overview of the structures, dynamics, and functions of this diverse set. Then, using a phylogenetic analysis to examine actin evolution, we show that the actin-related protein families that form polymers are more closely related to one another than they are to other nonpolymerizing members of the actin superfamily. Thus all the known actin-like polymers are likely to be the descendants of a single, ancestral, polymer-forming actin-like protein.

Interaction of the Femtosecond Laser Pulses with the New Silica Nanocomposites Containing Au and CdS

2013 ◽  
Vol 834-836 ◽  
pp. 60-63 ◽  
Author(s):  
Dmitriy Proschenko ◽  
Alexandr Mayor ◽  
Oleg Bukin ◽  
Sergey Golik ◽  
Alexey Chekhlenok ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Laser Pulses ◽  
Component Composition ◽  
Femtosecond Laser Pulses ◽  
Cds Nanoparticles ◽  
Experimental Conditions ◽  
Silica Nanocomposites ◽  
Filament Structure

Our work is dedicated for review of the synthesis of the new nanocomposite media with Au and CdS nanoparticles. Also formation of filament structure in presented samples as result of interaction with femtosecond laser pulses in depending on the component composition of the samples and the various experimental conditions was investigated.

scholarly journals Side-binding proteins modulate actin filament dynamics

2014 ◽  
Author(s):  
Alvaro H. Crevenna ◽  
Marcelino Arciniega ◽  
Aurelie Dupont ◽  
Kaja Kowalska ◽  
Oliver Lange ◽  
...  
Keyword(s):  
Actin Filament ◽  
Brownian Dynamics ◽  
Actin Polymerization ◽  
Actin Dynamics ◽  
Central Feature ◽  
Filament Dynamics ◽  
Filament Structure ◽  
The Rich ◽  
Dynamics Simulations ◽  
Pointed End

Actin filament dynamics govern many key physiological processes from cell motility to tissue morphogenesis. A central feature of actin dynamics is the capacity of the filament to polymerize and depolymerize at its ends in response to cellular conditions. It is currently thought that filament kinetics can be described by a single rate constant for each end. Here, using direct visualization of single actin filament elongation, we show that actin polymerization kinetics at both filament ends are strongly influenced by proteins that bind to the lateral filament surface. We also show that the less dynamic end, called the pointed-end, has a non-elongating state that dominates the observed filament kinetic asymmetry. Estimates of filament flexibility and Brownian dynamics simulations suggest that the observed kinetic diversity arises from structural alteration. Tuning filament kinetics by exploiting the natural malleability of the actin filament structure may be a ubiquitous mechanism to generate the rich variety of observed cellular actin dynamics.

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