scholarly journals Rules for the self-assembly of ESCRT-III on endosomes

2021 ◽  
Author(s):  
Simon Sprenger ◽  
Simona M. Migliano ◽  
Florian Oleschko ◽  
Marvin Kobald ◽  
Michael Hess ◽  
...  

ABSTRACTThe endosomal sorting complexes required for transport (ESCRT) mediate various membrane remodeling processes in cells by mechanism that are incompletely understood. Here we combined genetic experiments in budding yeast with site-specific cross-linking to identify rules that govern the self-assembly of individual ESCRT-III proteins into functional ESCRT-III complexes on endosomes. Together with current structural models of ESCRT-III, our findings suggest that, once nucleated, the growing Snf7 protofilament seeds the lateral co-assembly of a Vps24 - Vps2 heterofilament. Both Vps24 and Vps2 use positively charged amino acid residues in their helices α1 to interact with negatively charged amino acids in helix α4 of Snf7 subunits of the protofilament. In the Vps24 - Vps2 heterofilament, the two subunits alternate and interact with each other using hydrophobic interactions between helices α2/α3. The co-assembly of the Vps24 - Vps2 heterofilament restricts the lateral expansion of Snf7 protofilaments and leads the immediate recruitment of the AAA-ATPase Vps4. This self-assembly process of three ESCRT-III subunits results in the formation of a Snf7 protofilament and the co-assembly of a Vps24 - Vps2 heterofilament. This sets the stage for Vps4 recruitment and the subsequent ATP-driven dynamic self-organization of ESCRT-III / Vps4 assemblies and the ensuing membrane budding and scission events.

ChemPhotoChem ◽  
2020 ◽  
Vol 4 (7) ◽  
pp. 481-486
Author(s):  
Mei‐Yu Yeh ◽  
Tzu‐Yu Tseng ◽  
Hui‐Chun Hsieh ◽  
Bao‐Xing Wu ◽  
Yi‐Shun Liao ◽  
...  

Nanomaterials ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 285 ◽  
Author(s):  
Li Wang ◽  
Coucong Gong ◽  
Xinzhu Yuan ◽  
Gang Wei

Biomolecular self-assembly provides a facile way to synthesize functional nanomaterials. Due to the unique structure and functions of biomolecules, the created biological nanomaterials via biomolecular self-assembly have a wide range of applications, from materials science to biomedical engineering, tissue engineering, nanotechnology, and analytical science. In this review, we present recent advances in the synthesis of biological nanomaterials by controlling the biomolecular self-assembly from adjusting internal interactions and external stimulations. The self-assembly mechanisms of biomolecules (DNA, protein, peptide, virus, enzyme, metabolites, lipid, cholesterol, and others) related to various internal interactions, including hydrogen bonds, electrostatic interactions, hydrophobic interactions, π–π stacking, DNA base pairing, and ligand–receptor binding, are discussed by analyzing some recent studies. In addition, some strategies for promoting biomolecular self-assembly via external stimulations, such as adjusting the solution conditions (pH, temperature, ionic strength), adding organics, nanoparticles, or enzymes, and applying external light stimulation to the self-assembly systems, are demonstrated. We hope that this overview will be helpful for readers to understand the self-assembly mechanisms and strategies of biomolecules and to design and develop new biological nanostructures or nanomaterials for desired applications.


2012 ◽  
Vol 48 (16) ◽  
pp. 2210 ◽  
Author(s):  
Jenifer Rubio ◽  
Ignacio Alfonso ◽  
M. Isabel Burguete ◽  
Santiago V. Luis

2006 ◽  
Vol 400 (1) ◽  
pp. 23-32 ◽  
Author(s):  
Mio Horii ◽  
Hideki Shibata ◽  
Ryota Kobayashi ◽  
Keiichi Katoh ◽  
Chiharu Yorikawa ◽  
...  

All CHMPs (charged multivesicular body proteins) reported to date have common features: they all contain approx. 200 amino acid residues, have coiled-coil regions and have a biased distribution of charged residues (basic N-terminal and acidic C-terminal halves). Yeast orthologues of CHMPs, including an ESCRT-III component Snf7, are required for the sorting of cargo proteins to intraluminal vesicles of multivesicular bodies. We have characterized a novel human ESCRT-III-related protein, designated CHMP7, which consists of 453 amino acid residues. CHMP7 contains an SNF7 domain and a distantly SNF7-related domain in its C-terminal half and N-terminal half respectively. Among the ten CHMP proteins classified previously in six subfamilies (CHMP1–CHMP6), the C-terminal SNF7 domain of CHMP7 is most similar to the SNF7 domain of CHMP6, which associates with CHMP4 proteins and EAP20, a component of ESCRT-II. Pull-down assays using lysates of HEK-293T (human embryonic kidney) cells that overexpressed Strep-tagged CHMP7 and GFP (green fluorescent protein)-fused CHMP4b (also named Shax1) revealed a positive interaction between the C-terminal half of CHMP7 and CHMP4b. However, interaction was not observed between CHMP7 and EAP20. Confocal fluorescence microscopic analyses revealed that FLAG–CHMP7 is distributed in HeLa cells diffusely throughout the cytoplasm, but with some accumulation, especially in the perinuclear area. The distribution of FLAG–CHMP7 was altered to a cytoplasmic punctate pattern by overexpression of either CHMP4b–GFP or GFP–Vps4BE235Q, a dominant-negative mutant of the AAA (ATPase associated with various cellular activities) Vps4B, and partially co-localized with them. Ubiquitinated proteins and endocytosed EGF accumulated in GFP–CHMP7-expressing cells. A dominant-negative effect of overexpressed GFP–CHMP7 was also observed in the release of virus-like particles from HEK-293T cells that transiently expressed the MLV (murine leukaemia virus) Gag protein. These results suggest that CHMP7, a novel CHMP4-associated ESCRT-III-related protein, functions in the endosomal sorting pathway.


Symmetry ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 1926
Author(s):  
Arnoud Jongeling ◽  
Carsten Svaneborg ◽  
Renko de Vries

The design of colloidal interactions to achieve target self-assembled structures has especially been done for compact objects such as spheres with isotropic interaction potentials, patchy spheres and other compact objects with patchy interactions. Inspired by the self-assembly of collagen-I fibrils and intermediate filaments, we here consider the design of interaction patterns on semiflexible chains that could drive their staggered assembly into regular (para)crystalline fibrils. We consider semiflexible chains composed of a finite number of types of interaction beads (uncharged hydrophilic, hydrophobic, positively charged and negatively charged) and optimize the sequence of these interaction beads with respect to the interaction energy of the semiflexible chains in a number of target-staggered crystalline packings. We find that structures with the lowest interaction energies, that form simple lattices, also have low values of L/D (where L is chain length and D is stagger). In the low interaction energy sequences, similar types of interaction beads cluster together to form stretches. Langevin Dynamics simulations confirm that semiflexible chains with optimal sequences self-assemble into the designed staggered (para)crystalline fibrils. We conclude that very simple interaction patterns should suffice to drive the assembly of long semiflexible chains into staggered (para)crystalline fibrils.


Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 541 ◽  
Author(s):  
André Carvalho ◽  
Juan Gallo ◽  
David Pereira ◽  
Patrícia Valentão ◽  
Paula Andrade ◽  
...  

Self-assembled peptide hydrogels have emerged in recent years as the new paradigm in biomaterials research. We have contributed to this field the development of hydrogels based on dehydrodipeptides N-capped with naproxen. The dehydrodipeptide hydrogels can be loaded with drugs, thus being potential nanocarriers for drug delivery. In this work novel dehydrodipeptides containing tyrosine and aspartic acid amino acid residues N-capped with naproxen and C-terminal dehydrophenylalanine were prepared and characterized. Superparamagnetic iron oxide nanoparticles (SPIONs) were incorporated into the dehydrodipeptide-based hydrogels and their effect on the self-assembly, structure and rheological and magnetic properties of the hydrogels was studied. Magnetic hydrogels, with incorporated SPIONs, displayed concentration-dependent T2-MRI contrast enhancement. Moreover, upon magnetic excitation (alternating magnetic field –AMF–) the SPIONs were able to generate a significant amount of heat. Hence, magnetic hyperthermia can be used as a remote trigger for release of drug cargos and SPIONs incorporated into the self-assembled dehydrodipeptide hydrogels.


2021 ◽  
Vol 54 ◽  
Author(s):  
Björn Lindman ◽  
Bruno Medronho ◽  
Luís Alves ◽  
Magnus Norgren ◽  
Lars Nordenskiöld

Abstract Desoxyribosenucleic acid, DNA, and cellulose molecules self-assemble in aqueous systems. This aggregation is the basis of the important functions of these biological macromolecules. Both DNA and cellulose have significant polar and nonpolar parts and there is a delicate balance between hydrophilic and hydrophobic interactions. The hydrophilic interactions related to net charges have been thoroughly studied and are well understood. On the other hand, the detailed roles of hydrogen bonding and hydrophobic interactions have remained controversial. It is found that the contributions of hydrophobic interactions in driving important processes, like the double-helix formation of DNA and the aqueous dissolution of cellulose, are dominating whereas the net contribution from hydrogen bonding is small. In reviewing the roles of different interactions for DNA and cellulose it is useful to compare with the self-assembly features of surfactants, the simplest case of amphiphilic molecules. Pertinent information on the amphiphilic character of cellulose and DNA can be obtained from the association with surfactants, as well as on modifying the hydrophobic interactions by additives.


Soft Matter ◽  
2018 ◽  
Vol 14 (30) ◽  
pp. 6320-6326 ◽  
Author(s):  
Edward D. H. Mansfield ◽  
Matthias Hartlieb ◽  
Sylvain Catrouillet ◽  
Julia Y. Rho ◽  
Sophie C. Larnaudie ◽  
...  

Self-assembling cyclic peptides (CP) consisting of amino acids with alternating d- and l-chirality form nanotubes by hydrogen bonding, hydrophobic interactions, and π–π stacking in solution.


2021 ◽  
Author(s):  
Carolina Conter ◽  
Luca Bombardi ◽  
Marco Pedretti ◽  
Filippo Favretto ◽  
Adele Di Matteo ◽  
...  

Centrins are conserved calcium (Ca2+)-binding proteins typically associated with centrosomes that have been implicated in several biological processes. In Toxoplasma gondii, a parasite that causes toxoplasmosis, three centrin isoforms have been recognized. We have recently characterized the metal binding and structural features of isoform 1 (TgCEN1), demonstrating that it possesses properties consistent with a role as a Ca2+ sensor and displays a Ca2+-dependent tendency to self-assemble. Herein, we expanded our studies, focusing on the self-association and target binding properties of TgCEN1 by combining biophysical techniques including dynamic light scattering, isothermal titration calorimetry, nuclear magnetic resonance, circular dichroism, and fluorescence spectroscopy. We found that the self-assembly process of TgCEN1 depends on different physicochemical factors, including Ca2+ concentration, temperature, and protein concentration, and is mediated by both electrostatic and hydrophobic interactions. The process is completely abolished upon removal of the first 21-residues of the protein and is significantly reduced in the presence of a binding target peptide derived from the human XPC protein (P17-XPC). Titration of P17-XPC to the intact protein and isolated domains showed that TgCEN1 possesses two binding sites with distinct affinities and Ca2+ sensitivity; a high-affinity site in the C-lobe which may be constitutively bound to the peptide and a low-affinity site in the N-lobe which is active only upon Ca2+ stimulus. Overall, our results suggest a specific mechanism of TgCEN1 for Ca2+-modulated target binding and support a N-to-C self-assembly mode, in which the first 21-residues of one molecule likely interact with the C-lobe of the other.


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