scholarly journals Cryo-EM structure of the activated NAIP2-NLRC4 inflammasome reveals nucleated polymerization

Science ◽  
2015 ◽  
Vol 350 (6259) ◽  
pp. 404-409 ◽  
Author(s):  
L. Zhang ◽  
S. Chen ◽  
J. Ruan ◽  
J. Wu ◽  
A. B. Tong ◽  
...  
Keyword(s):  
Nucleated Polymerization

scholarly journals Nucleated polymerization with secondary pathways. III. Equilibrium behavior and oligomer populations

2011 ◽  
Vol 135 (6) ◽  
pp. 065107 ◽  
Author(s):  
Samuel I. A. Cohen ◽  
Michele Vendruscolo ◽  
Christopher M. Dobson ◽  
Tuomas P. J. Knowles
Keyword(s):  
Equilibrium Behavior ◽  
Nucleated Polymerization

Abstract B134:Cryo-EMstructure of the activated NAIP2-NLRC4 inflammasome reveals nucleated polymerization

2016 ◽  
Author(s):  
Liman Zhang ◽  
Shuobing Chen ◽  
Jianbin Ruan ◽  
Liron David ◽  
Youdong Mao ◽  
...  
Keyword(s):  
Nucleated Polymerization

scholarly journals Molecular interactions of amyloid nanofibrils with biological aggregation modifiers: implications for cytotoxicity mechanisms and biomaterial design

2017 ◽  
Vol 7 (4) ◽  
pp. 20160160 ◽  
Author(s):  
Durga Dharmadana ◽  
Nicholas P. Reynolds ◽  
Charlotte E. Conn ◽  
Céline Valéry
Keyword(s):  
Molecular Interactions ◽  
Lipid Membranes ◽  
Reaction Pathway ◽  
Third Party ◽  
Final Word ◽  
Nucleated Polymerization ◽  
Wide Range ◽  
Non Covalent Interactions ◽  
Functional Amyloids ◽  
Covalent Interactions

Amyloid nanofibrils are ubiquitous biological protein fibrous aggregates, with a wide range of either toxic or beneficial activities that are relevant to human disease and normal biology. Protein amyloid fibrillization occurs via nucleated polymerization, through non-covalent interactions. As such, protein nanofibril formation is based on a complex interplay between kinetic and thermodynamic factors. The process entails metastable oligomeric species and a highly thermodynamically favoured end state. The kinetics, and the reaction pathway itself, can be influenced by third party moieties, either molecules or surfaces. Specifically, in the biological context, different classes of biomolecules are known to act as catalysts, inhibitors or modifiers of the generic protein fibrillization process. The biological aggregation modifiers reviewed here include lipid membranes of varying composition, glycosaminoglycans and metal ions, with a final word on xenobiotic compounds. The corresponding molecular interactions are critically analysed and placed in the context of the mechanisms of cytotoxicity of the amyloids involved in diverse pathologies and the non-toxicity of functional amyloids (at least towards their biological host). Finally, the utilization of this knowledge towards the design of bio-inspired and biocompatible nanomaterials is explored.

scholarly journals Nucleated polymerization of actin from the membrane-associated ends of microvillar filaments in the intestinal brush border.

1982 ◽  
Vol 95 (1) ◽  
pp. 223-233 ◽  
Author(s):  
M S Mooseker ◽  
T D Pollard ◽  
K A Wharton
Keyword(s):  
Ionic Strength ◽  
Intestinal Epithelial ◽  
Capping Protein ◽  
The Core ◽  
Nucleated Polymerization ◽  
Myosin Subfragment ◽  
Brush Borders ◽  
Pointed End ◽  
Low Ionic Strength

We examined the nucleated polymerization of actin from the two ends of filaments that comprise the microvillus (MV) core in intestinal epithelial cells by electron microscopy. Three different in vitro preparations were used to nucleate the polymerization of muscle G-actin: (a) MV core fragments containing "barbed" and "pointed" filament ends exposed by shear during isolation, (b) isolated, membrane-intact brush borders, and (c) brush borders demembranated with Triton-X 100. It has been demonstrated that MV core fragments nucleate filament growth from both ends with a strong bias for one end. Here we identify the barbed end of the core fragment as the fast growing end by decoration with myosin subfragment one. Both cytochalasin B (CB) and Acanthamoeba capping protein block filament growth from the barbed but not the pointed end of MV core fragments. To examine actin assembly from the naturally occurring, membrane-associated ends of MV core filaments, isolated membrane-intact brush borders were used to nucleate the polymerization of G-actin. Addition of salt (75 mM KCl, 1 mM MgSO4) to brush borders preincubated briefly at low ionic strength with G-actin induced the formation of 0.2-0.4 micron "growth zones" at the tips of microvilli. The dense plaque at the tip of the MV core remains associated with the membrane and the presumed growing ends of the filaments. We also observed filament growth from the pointed ends of core filaments in the terminal web. We did not observe filament growth at the membrane-associated ends of core filaments when the latter were in the presence of 2 microM CB or if the low ionic strength incubation step was omitted. Addition of G-actin to demembranated brush borders, which retain the dense plaque on their MV tips, resulted in filament growth from both ends of the MV core. Again, 2 microM CB blocked filament growth from only the barbed (tip) end of the core. The dense plaque remained associated with the tip-end of the core in the presence of CB but usually was dislodged in control preparations where nucleated polymerization from the tip-end of the core occurred. Our results support the notion that microvillar assembly and changes in microvillar length could occur by actin monomer addition/loss at the barbed, membrane-associated ends of MV core filaments.

scholarly journals The 8 and 5 kDa Fragments of Plasma Gelsolin Form Amyloid Fibrils by a Nucleated Polymerization Mechanism, while the 68 kDa Fragment Is Not Amyloidogenic

Biochemistry ◽  
2009 ◽  
Vol 48 (48) ◽  
pp. 11370-11380 ◽  
Author(s):  
James P. Solomon ◽  
Isaac T. Yonemoto ◽  
Amber N. Murray ◽  
Joshua L. Price ◽  
Evan T. Powers ◽  
...  
Keyword(s):  
Amyloid Fibrils ◽  
Polymerization Mechanism ◽  
Plasma Gelsolin ◽  
Nucleated Polymerization

scholarly journals Genetic Study of Interactions Between the Cytoskeletal Assembly Protein Sla1 and Prion-Forming Domain of the Release Factor Sup35 (eRF3) in Saccharomyces cerevisiae

Genetics ◽  
1999 ◽  
Vol 153 (1) ◽  
pp. 81-94 ◽  
Author(s):  
Peggy A Bailleul ◽  
Gary P Newnam ◽  
Judith N Steenbergen ◽  
Yury O Chernoff
Keyword(s):  
De Novo ◽  
Normal Function ◽  
Proximal Fragment ◽  
Release Factor ◽  
Nucleated Polymerization ◽  
Translational Readthrough ◽  
Prion Propagation ◽  
Structural Networks ◽  
Translational Apparatus ◽  
Two Hybrid

Abstract Striking similarities between cytoskeletal assembly and the “nucleated polymerization” model of prion propagation suggest that similar or overlapping sets of proteins may assist in both processes. We show that the C-terminal domain of the yeast cytoskeletal assembly protein Sla1 (Sla1C) specifically interacts with the N-terminal prion-forming domain (Sup35N) of the yeast release factor Sup35 (eRF3) in the two-hybrid system. Sla1C and several other Sup35N-interacting proteins also exhibit two-hybrid interactions with the poly-Gln-expanded N-proximal fragment of human huntingtin, which promotes Huntington disease-associated aggregation. The Sup35N-Sla1C interaction is inhibited by Sup35N alterations that make Sup35 unable to propagate the [PSI+] state and by the absence of the chaperone protein Hsp104, which is essential for [PSI] propagation. In a Sla1– background, [PSI] curing by dimethylsulfoxide or excess Hsp104 is increased, while translational readthrough and de novo [PSI] formation induced by excess Sup35 or Sup35N are decreased. These data show that, in agreement with the proposed function of Sla1 during cytoskeletal formation, Sla1 assists in [PSI] formation and propagation, but is not required for these processes. Sla1– strains are sensitive to some translational inhibitors, and some sup35 mutants, obtained in a Sla1– background, are sensitive to Sla1, suggesting that the interaction between Sla1 and Sup35 proteins may play a role in the normal function of the translational apparatus. We hypothesize that Sup35N is involved in regulatory interactions with intracellular structural networks, and [PSI] prion may be formed as a by-product of this process.

scholarly journals Nucleated polymerization with secondary pathways. I. Time evolution of the principal moments

2011 ◽  
Vol 135 (6) ◽  
pp. 065105 ◽  
Author(s):  
Samuel I. A. Cohen ◽  
Michele Vendruscolo ◽  
Mark E. Welland ◽  
Christopher M. Dobson ◽  
Eugene M. Terentjev ◽  
...  
Keyword(s):  
Time Evolution ◽  
Nucleated Polymerization
Sign in / Sign up

Export Citation Format

Share Document