@article{21369, abstract = {Formation of new amyloid fibrils and oligomers from monomeric protein on the surfaces of existing fibrils is an important driver of many disorders such as Alzheimer’s and Parkinson’s diseases. The structural basis of this secondary nucleation process, however, is poorly understood. Here, we ask whether secondary nucleation sites are found predominantly at rare growth defects: irregularities in the fibril core structure incorporated during their original assembly. We first demonstrate using the specific inhibitor of secondary nucleation, Brichos, that secondary nucleation sites on Alzheimer’s disease-associated fibrils composed of Aβ40 and Aβ42 peptides are rare compared to the number of protein molecules they contain. We then grow Aβ40 fibrils under conditions designed to eliminate most growth defects while leaving the regular fibril morphology unchanged, and confirm the latter using cryo-electron microscopy. We measure both the ability of these annealed fibrils to promote secondary nucleation and the stoichiometry of their secondary nucleation sites, finding that both are greatly reduced as predicted. Re-analysis of published data for other proteins suggests that fibril growth defects may also drive secondary nucleation generally across most amyloids. These findings could unlock structure-based drug design of therapeutics that aim to halt amyloid disorders by inhibiting secondary nucleation sites.}, author = {Hu, Jing and Scheidt, Tom and Thacker, Dev and Axell, Emil and Stemme, Elin and Łapińska, Urszula and Wennmalm, Stefan and Meisl, Georg and Curk, Samo and Andreasen, Maria and Vendruscolo, Michele and Arosio, Paolo and Šarić, Anđela and Schmit, Jeremy D. and Knowles, Tuomas P.J. and Sparr, Emma and Linse, Sara and Michaels, Thomas C.T. and Dear, Alexander J.}, issn = {2041-1723}, journal = {Nature Communications}, publisher = {Springer Nature}, title = {{Structural defects in amyloid-β fibrils drive secondary nucleation}}, doi = {10.1038/s41467-026-69377-1}, volume = {17}, year = {2026}, } @article{21748, abstract = {Cells are defined by lipid membranes that differ in their structure across the tree of life. While the membranes of most bacteria and eukaryotes consist of single-headed bilayer lipids, the membranes of archaea are composed of mixtures of single-headed bilayer lipids and double-headed bolalipids. Archaeal bolalipids can adopt straight or u-shaped conformations, enabling them—together with bilayer lipids—to control whether membranes form bilayer or monolayer structures. Yet, the physical principles governing archaeal membranes remain largely unexplored, especially how membrane structure couples to externally imposed curvature during membrane remodeling. Here, we perform coarse-grained molecular dynamics simulations of toroidal vesicles to systematically probe the effects of all relevant combinations of mean and Gaussian curvatures on shape stability and lipid organization. We find that soft bilayer membranes can sustain all curvatures induced, whereas rigid bolalipid monolayer membranes either transition to different vesicle shapes or rupture. Bilayer-mimicking u-shaped bolalipids and bilayer lipids are spatially accumulated in regions of high mean membrane curvature independent of Gaussian curvature. Our work identifies curvature–composition coupling as a physical signature of archaeal membrane remodeling.}, author = {Frey, Felix F and Santana de Freitas Amaral, Miguel and Šarić, Anđela}, issn = {1089-7690}, journal = {Journal of Chemical Physics}, number = {14}, publisher = {AIP Publishing}, title = {{Cracking donuts and sorting lipids: Geometry controls archaeal membrane stability and lipid organization}}, doi = {10.1063/5.0325170}, volume = {164}, year = {2026}, } @article{21749, abstract = {The collagen triple helix assembles hierarchically into bundled oligomers, solvated networks, and fibers. Synthetic peptide assemblies, driven by supramolecular interactions, can form single triple helices through intrahelical amino acid pairs; however, the principles guiding interhelical associations into higher-order structures remain unclear. Here, we incorporate cation−π and electrostatic charge pairs to probe interhelical interactions and elucidate the mechanisms driving triple helix assembly into fibrils, nanotubes, and nanosheets. Introducing cation−π pairs into a fibrillating collagen mimetic resulted in D-periodic fibrils with pH-sensitive gelation. By alternating the presentation of electrostatic and cation−π pairs, the assembly of another D-periodic fibril featuring inner and outer triple-helical layers was resolved by cryo electron microscopy to a resolution of 8 Å. At physiological pH, antiparallel association of these triple helices leads to the formation of nanotubes. The packing behavior of triple helices correlates with the interhelical interactions, where parallel associations favor fibril formation and antiparallel interactions drive nanotube and nanosheet assembly. These self-assembling triple-helical peptides demonstrate how packing of higher-order structures can be tailored with supramolecular interactions and establish the relationship of different hierarchical collagen-mimetic assemblies as pH-dependent.}, author = {Cole, Carson C. and Kreutzberger, Mark A.B. and Klein, Kevin and Cahue, Kiana A. and Pogostin, Brett H. and Farsheed, Adam C. and Swain, Joseph W.R. and Bui, Thi H. and Dey, Arghadip and Makhoul, Jonathan T. and Dubackic, Marija and Pal, Antara and Olsson, Ulf and Šarić, Anđela and Egelman, Edward H. and Hartgerink, Jeffrey D.}, issn = {1526-4602}, journal = {Biomacromolecules}, number = {4}, pages = {2956--2965}, publisher = {American Chemical Society}, title = {{Supramolecular assembly of collagen-mimetic eptide D-periodic fibrils and nanoassemblies}}, doi = {10.1021/acs.biomac.6c00345}, volume = {27}, year = {2026}, } @misc{21800, abstract = {LAMMPS input scripts to simulate toroidal vesicles composed of pure bolalipid membranes and archaeal mixture membranes for the following publication: "Cracking donuts and sorting lipids: geometry controls archaeal membrane stability and lipid organization" by Felix Frey, Miguel Amaral, and Andela Saric.}, author = {Frey, Felix F and Santana de Freitas Amaral, Miguel and Šarić, Anđela}, publisher = {Zenodo}, title = {{Cracking donuts and sorting lipids: Geometry controls archaeal membrane stability and lipid organization}}, doi = {10.5281/ZENODO.18772086}, year = {2026}, } @article{22955, abstract = {The regulation of 3D cell shape is a fundamental problem of life. In multicellular tissues, cell shape emerges through the balance of forces inside and outside the cell. In epithelia, the basement membrane (BM) is the first extracellular barrier that cells sense biochemically and mechanically. Despite this, little is known about how BM mechanical properties are regulated and how they impact cell shape. Through mathematical modeling, we show that the stress relaxation time of the BM can regulate cell shape. Using molecular dynamics simulations, we show that the stress relaxation time of a collagen IV network can be inferred from the lifetime of collagen IV molecules. To measure collagen IV lifetime in vivo, we develop a fluorescent timer reporter for collagen IV and show that perlecan modifies collagen IV lifetime. This cross-disciplinary approach establishes a multiscale framework to probe matrix turnover, and its regulation and function in cell shape control.}, author = {Barrientos, Ricardo and Meadowcroft, Billie and Sánchez-Sánchez, Besaiz J. and Stramer, Brian M. and Paluch, Ewa K. and Charras, Guillaume and Banerjee, Shiladitya and Šarić, Anđela and Mao, Yanlan}, issn = {1097-4172}, journal = {Cell}, number = {18}, pages = {5611--5624.e4}, publisher = {Cell Press}, title = {{Basement membrane turnover controls cell shape}}, doi = {10.1016/j.cell.2026.07.010}, volume = {189}, year = {2026}, } @article{21235, abstract = {The condensation of charged polymers is an important driver for the formation of biomolecular condensates. Recent experiments suggest that this mechanism also controls the clustering of eukaryotic chromosomes during the late stages of cell division. In this process, interchromosome attraction is driven by the condensation of cytoplasmic RNA and Ki-67, a charged intrinsically disordered protein that coats the chromosomes as a brush. Attraction between chromosomes has been shown to be specifically promoted by a localized charged patch on Ki-67, although the physical mechanism remains unclear. To elucidate this process, we combine coarse-grained simulations and analytical theory to study the RNA-mediated interaction between charged polymer brushes on the chromosome surfaces. We show that the charged patch on Ki-67 leads to interchromosome attraction via RNA bridging between the two brushes, whereby the RNA preferentially interacts with the charged patches, leading to stable, long-range forces. By contrast, if the brush is uniformly charged, bridging is basically absent due to complete adsorption of RNA onto the brush. Moreover, the RNA dynamics becomes caged in presence of the charged patch while remaining diffusive with uniform charge. Our work sheds light on the physical origin of chromosome clustering, while also suggesting a general mechanism for cells to tune work production by biomolecular condensates via different charge distributions.}, author = {Sorichetti, Valerio and Robin, Paul and Palaia, Ivan and Hernandez-Armendariz, Alberto and Cuylen-Haering, Sara and Šarić, Anđela}, issn = {2835-8279}, journal = {PRX Life}, number = {3}, publisher = {American Physical Society}, title = {{Charge distribution of the coating brush drives interchromosome attraction}}, doi = {10.1103/41fd-r847}, volume = {3}, year = {2025}, } @article{21251, abstract = {Cellular membranes differ across the tree of life. In most bacteria and eukaryotes, single-headed lipids self-assemble into flexible bilayer membranes. By contrast, thermophilic archaea tend to possess bilayer lipids together with double-headed, monolayer spanning bolalipids, which are thought to enable cells to survive in harsh environments. Here, using a minimal computational model for bolalipid membranes, we explore the trade-offs at play when forming membranes. We find that flexible bolalipids form membranes that resemble bilayer membranes because they are able to assume a U-shaped conformation. Conversely, rigid bolalipids, which resemble the bolalipids with cyclic groups found in thermophilic archaea, take on a straight conformation and form membranes that are stiff and prone to pore formation when they undergo changes in shape. Strikingly, however, the inclusion of small amounts of bilayer lipids in a bolalipid membrane is enough to achieve fluid bolalipid membranes that are both stable and flexible, resolving this trade-off. Our study suggests a mechanism by which archaea can tune the material properties of their membranes as and when required to enable them to survive in harsh environments and to undergo essential membrane remodelling events like cell division.}, author = {Santana de Freitas Amaral, Miguel and Frey, Felix F and Jiang, Xiuyun and Baum, Buzz and Šarić, Anđela}, issn = {2050-084X}, journal = {eLife}, publisher = {eLife Sciences Publications}, title = {{Balancing stability and flexibility when reshaping archaeal membranes}}, doi = {10.7554/elife.105432}, volume = {14}, year = {2025}, } @article{21256, abstract = {Collagen IV is one of the main components of the basement membrane, a layer of material that lines the majority of tissues in multicellular organisms. Collagen IV molecules assemble into networks, providing stiffness and elasticity to tissues and informing cell and organ shape, especially during development. In this work, we develop two coarse-grained models for collagen IV molecules that retain biochemical bond specificity and coarse grain at different length scales. Through molecular-dynamics simulations, we test the assembly and mechanics of the resulting networks and measure their response to strain in terms of stress, microscopic alignment, and bond dynamics. Within the basement membrane, collagen IV networks rearrange by molecule turnover, which affects tissue organization and can be linked with enzyme activity. Here we explore network rearrangements via bond remodeling, the process of breaking and remaking of bonds between network molecules. We then investigate the effects of active (enzymatic) bond remodeling. We find that this nonequilibrium remodeling allows a network to keep its integrity under strain, while relaxing fully over a variety of timescales, a dynamic response that is unavailable to networks undergoing equilibrium remodeling.}, author = {Meadowcroft, Billie and Sorichetti, Valerio and Ratajczyk, Eryk and Perez Verdugo, Fernanda L and Khalilgharibi, Nargess and Mao, Yanlan and Palaia, Ivan and Šarić, Anđela}, issn = {2835-8279}, journal = {PRX Life}, publisher = {American Physical Society}, title = {{Nonequilibrium remodeling of collagen IV networks in Silico}}, doi = {10.1103/gdd5-rnh7}, volume = {3}, year = {2025}, } @article{20318, abstract = {Lipid membranes and membrane deformations are a long-standing area of research in soft matter and biophysics. Computer simulations have complemented analytical and experimental approaches as one of the pillars in the field. However, setting up and using membrane simulations can come with barriers due to the multidisciplinary effort involved and the vast choice of existing simulations models. In this review, we introduce the non-expert reader to coarse-grained membrane simulations at the mesoscale. Firstly, we give a concise overview of the modelling approaches to study fluid membranes, together with guidance to more specialized references. Secondly, we provide a conceptual guide on how to develop mesoscale membrane simulations. Lastly, we construct a hands-on tutorial on how to apply mesoscale membrane simulations, by providing a pedagogical examination of membrane tether pulling, shape and mechanics of membrane tubes, and membrane fluctuations with three different membrane models, and discussing them in terms of their scope and how resource-intensive they are. To ease the reader's venture into the field, we provide a repository with ready-to-run tutorials.}, author = {Muñoz Basagoiti, Maitane and Frey, Felix F and Meadowcroft, Billie and Santana de Freitas Amaral, Miguel and Prada, Adam and Šarić, Anđela}, issn = {1744-6848}, journal = {Soft Matter}, number = {40}, pages = {7736--7756}, publisher = {Royal Society of Chemistry}, title = {{A tutorial for mesoscale computer simulations of lipid membranes: Tether pulling, tubulation and fluctuations}}, doi = {10.1039/d5sm00148j}, volume = {21}, year = {2025}, } @article{20530, abstract = {Cells must coordinate DNA segregation with cytokinesis to ensure that each daughter cell inherits a complete genome. Here, we explore how DNA segregation and division are mechanistically coupled in archaeal relatives of eukaryotes, which lack Cyclin-dependent kinase (CDK)/Cyclins. Using live cell imaging, we first describe the series of sequential changes in DNA organization that accompany cell division in Sulfolobus, which computational modeling shows likely aid genome segregation. Through a perturbation analysis we identify a regulatory checkpoint which ensures that the compaction of the genome into two spatially segregated nucleoids only occurs once cells have assembled a division ring—which also defines the axis of DNA segregation. Finally, we show that DNA compaction and segregation depend, in part, on a ParA homologue, SegA, and its partner SegB, whose absence leads to bridging DNA. Taken together, these data show how regulatory checkpoints like those operating in eukaryotes aid high-fidelity division in an archaeon.}, author = {Parham, Joe and Sorichetti, Valerio and Cezanne, Alice and Foo, Sherman and Kuo, Yin Wei and Hoogenberg, Baukje and Radoux-Mergault, Arthur and Mawdesley, Eloise and Gatward, Lydia Daniels and Boulanger, Jerome and Schulze, Ulrike and Šarić, Anđela and Baum, Buzz}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences}, number = {42}, pages = {e2513939122}, publisher = {National Academy of Sciences}, title = {{Temporal and spatial coordination of DNA segregation and cell division in an archaeon}}, doi = {10.1073/pnas.2513939122}, volume = {122}, year = {2025}, } @article{14844, abstract = {Many cell functions require a concerted effort from multiple membrane proteins, for example, for signaling, cell division, and endocytosis. One contribution to their successful self-organization stems from the membrane deformations that these proteins induce. While the pairwise interaction potential of two membrane-deforming spheres has recently been measured, membrane-deformation-induced interactions have been predicted to be nonadditive, and hence their collective behavior cannot be deduced from this measurement. We here employ a colloidal model system consisting of adhesive spheres and giant unilamellar vesicles to test these predictions by measuring the interaction potential of the simplest case of three membrane-deforming, spherical particles. We quantify their interactions and arrangements and, for the first time, experimentally confirm and quantify the nonadditive nature of membrane-deformation-induced interactions. We furthermore conclude that there exist two favorable configurations on the membrane: (1) a linear and (2) a triangular arrangement of the three spheres. Using Monte Carlo simulations, we corroborate the experimentally observed energy minima and identify a lowering of the membrane deformation as the cause for the observed configurations. The high symmetry of the preferred arrangements for three particles suggests that arrangements of many membrane-deforming objects might follow simple rules.}, author = {Azadbakht, Ali and Meadowcroft, Billie and Majek, Juraj and Šarić, Anđela and Kraft, Daniela J.}, issn = {1542-0086}, journal = {Biophysical Journal}, number = {3}, pages = {307--316}, publisher = {Elsevier}, title = {{Nonadditivity in interactions between three membrane-wrapped colloidal spheres}}, doi = {10.1016/j.bpj.2023.12.020}, volume = {123}, year = {2024}, } @article{15001, abstract = {Self-replication of amyloid fibrils via secondary nucleation is an intriguing physicochemical phenomenon in which existing fibrils catalyze the formation of their own copies. The molecular events behind this fibril surface-mediated process remain largely inaccessible to current structural and imaging techniques. Using statistical mechanics, computer modeling, and chemical kinetics, we show that the catalytic structure of the fibril surface can be inferred from the aggregation behavior in the presence and absence of a fibril-binding inhibitor. We apply our approach to the case of Alzheimer’s A amyloid fibrils formed in the presence of proSP-C Brichos inhibitors. We find that self-replication of A fibrils occurs on small catalytic sites on the fibril surface, which are far apart from each other, and each of which can be covered by a single Brichos inhibitor.}, author = {Curk, Samo and Krausser, Johannes and Meisl, Georg and Frenkel, Daan and Linse, Sara and Michaels, Thomas C.T. and Knowles, Tuomas P.J. and Šarić, Anđela}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {7}, publisher = {National Academy of Sciences}, title = {{Self-replication of Aβ42 aggregates occurs on small and isolated fibril sites}}, doi = {10.1073/pnas.2220075121}, volume = {121}, year = {2024}, } @article{15116, abstract = {Water is known to play an important role in collagen self-assembly, but it is still largely unclear how water–collagen interactions influence the assembly process and determine the fibril network properties. Here, we use the H2O/D2O isotope effect on the hydrogen-bond strength in water to investigate the role of hydration in collagen self-assembly. We dissolve collagen in H2O and D2O and compare the growth kinetics and the structure of the collagen assemblies formed in these water isotopomers. Surprisingly, collagen assembly occurs ten times faster in D2O than in H2O, and collagen in D2O self-assembles into much thinner fibrils, that form a more inhomogeneous and softer network, with a fourfold reduction in elastic modulus when compared to H2O. Combining spectroscopic measurements with atomistic simulations, we show that collagen in D2O is less hydrated than in H2O. This partial dehydration lowers the enthalpic penalty for water removal and reorganization at the collagen–water interface, increasing the self-assembly rate and the number of nucleation centers, leading to thinner fibrils and a softer network. Coarse-grained simulations show that the acceleration in the initial nucleation rate can be reproduced by the enhancement of electrostatic interactions. These results show that water acts as a mediator between collagen monomers, by modulating their interactions so as to optimize the assembly process and, thus, the final network properties. We believe that isotopically modulating the hydration of proteins can be a valuable method to investigate the role of water in protein structural dynamics and protein self-assembly.}, author = {Giubertoni, Giulia and Feng, Liru and Klein, Kevin and Giannetti, Guido and Rutten, Luco and Choi, Yeji and Van Der Net, Anouk and Castro-Linares, Gerard and Caporaletti, Federico and Micha, Dimitra and Hunger, Johannes and Deblais, Antoine and Bonn, Daniel and Sommerdijk, Nico and Šarić, Anđela and Ilie, Ioana M. and Koenderink, Gijsje H. and Woutersen, Sander}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {11}, publisher = {National Academy of Sciences}, title = {{Elucidating the role of water in collagen self-assembly by isotopically modulating collagen hydration}}, doi = {10.1073/pnas.2313162121}, volume = {121}, year = {2024}, } @article{18526, abstract = {Multivesicular endosomes (MVEs) sequester membrane proteins destined for degradation within intralumenal vesicles (ILVs), a process mediated by the membrane-remodeling action of Endosomal Sorting Complex Required for Transport (ESCRT) proteins. In Arabidopsis, endosomal membrane constriction and scission are uncoupled, resulting in the formation of extensive concatenated ILV networks and enhancing cargo sequestration efficiency. Here, we used a combination of electron tomography, computer simulations, and mathematical modeling to address the questions of when concatenated ILV networks evolved in plants and what drives their formation. Through morphometric analyses of tomographic reconstructions of endosomes across yeast, algae, and various land plants, we have found that ILV concatenation is widespread within plant species, but only prevalent in seed plants, especially in flowering plants. Multiple budding sites that require the formation of pores in the limiting membrane were only identified in hornworts and seed plants, suggesting that this mechanism has evolved independently in both plant lineages. To identify the conditions under which these multiple budding sites can arise, we used particle-based molecular dynamics simulations and found that changes in ESCRT filament properties, such as filament curvature and membrane binding energy, can generate the membrane shapes observed in multiple budding sites. To understand the relationship between membrane budding activity and ILV network topology, we performed computational simulations and identified a set of membrane remodeling parameters that can recapitulate our tomographic datasets.}, author = {Weiner, Ethan and Berryman, Elizabeth and Frey, Felix F and Solís, Ariadna González and Leier, André and Lago, Tatiana Marquez and Šarić, Anđela and Otegui, Marisa S.}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {44}, publisher = {National Academy of Sciences}, title = {{Endosomal membrane budding patterns in plants}}, doi = {10.1073/pnas.2409407121}, volume = {121}, year = {2024}, } @article{18072, abstract = {The individualization of chromosomes during early mitosis and their clustering upon exit from cell division are two key transitions that ensure efficient segregation of eukaryotic chromosomes. Both processes are regulated by the surfactant-like protein Ki-67, but how Ki-67 achieves these diametric functions has remained unknown. Here, we report that Ki-67 radically switches from a chromosome repellent to a chromosome attractant during anaphase in human cells. We show that Ki-67 dephosphorylation during mitotic exit and the simultaneous exposure of a conserved basic patch induce the RNA-dependent formation of a liquid-like condensed phase on the chromosome surface. Experiments and coarse-grained simulations support a model in which the coalescence of chromosome surfaces, driven by co-condensation of Ki-67 and RNA, promotes clustering of chromosomes. Our study reveals how the switch of Ki-67 from a surfactant to a liquid-like condensed phase can generate mechanical forces during genome segregation that are required for re-establishing nuclear-cytoplasmic compartmentalization after mitosis.}, author = {Hernandez-Armendariz, Alberto and Sorichetti, Valerio and Hayashi, Yuki and Koskova, Zuzana and Brunner, Andreas and Ellenberg, Jan and Šarić, Anđela and Cuylen-Haering, Sara}, issn = {1097-4164}, journal = {Molecular Cell}, number = {17}, pages = {P3254--3270.E9}, publisher = {Cell Press}, title = {{A liquid-like coat mediates chromosome clustering during mitotic exit}}, doi = {10.1016/j.molcel.2024.07.022}, volume = {84}, year = {2024}, } @article{17239, abstract = {Collagen is the most abundant protein in tissue scaffolds in live organisms. Collagen can self-assemble in vitro, which has led to a number of biotechnological and biomedical applications. To understand the dominant factors that participate in the formation of collagen nanostructures, here we study in real time and with nanoscale resolution the disassembly and reassembly of collagens. We implement a high-speed force microscope, which provides in situ high spatiotemporal resolution images of collagen nanostructures under changing pH conditions. The disassembly and reassembly are dominated by the electrostatic interactions among amino-acid residues of different molecules. Acidic conditions favor disassembly by neutralizing negatively charged residues. The process sets a net repulsive force between collagen molecules. A neutral pH favors the presence of negative and positively charged residues along the collagen molecules, which promotes their electrostatic attraction. Molecular dynamics simulations reproduce the experimental behavior and validate the electrostatic-based model of the disassembly and reassembly processes.}, author = {Garcia-Sacristan, Clara and Gisbert, Victor G. and Klein, Kevin and Šarić, Anđela and Garcia, Ricardo}, issn = {1936-086X}, journal = {ACS Nano}, number = {28}, pages = {18485--18492}, publisher = {American Chemical Society}, title = {{In operando imaging electrostatic-driven disassembly and reassembly of collagen nanostructures}}, doi = {10.1021/acsnano.4c03839}, volume = {18}, year = {2024}, } @article{17460, abstract = {Filaments in the cell commonly treadmill. Driven by energy consumption, they grow on one end while shrinking on the other, causing filaments to appear motile even though individual proteins remain static. This process is characteristic of cytoskeletal filaments and leads to collective filament self-organization. Here we show that treadmilling drives filament nematic ordering by dissolving misaligned filaments. Taking the bacterial FtsZ protein involved in cell division as an example, we show that this mechanism aligns FtsZ filaments in vitro and drives the organization of the division ring in living Bacillus subtilis cells. We find that ordering via local dissolution also allows the system to quickly respond to chemical and geometrical biases in the cell, enabling us to quantitatively explain the ring formation dynamics in vivo. Beyond FtsZ and other cytoskeletal filaments, our study identifies a mechanism for self-organization via constant birth and death of energy-consuming filaments.}, author = {Vanhille-Campos, Christian Eduardo and Whitley, Kevin D. and Radler, Philipp and Loose, Martin and Holden, Séamus and Šarić, Anđela}, issn = {1745-2481}, journal = {Nature Physics}, pages = {1670--1678}, publisher = {Springer Nature}, title = {{Self-organization of mortal filaments and its role in bacterial division ring formation}}, doi = {10.1038/s41567-024-02597-8}, volume = {20}, year = {2024}, } @unpublished{18670, abstract = {Across the tree of life, distinct designs of cellular membranes have evolved. In bacteria and eukaryotes single-headed lipids self-assemble into flexible bilayer membranes. By contrast, archaea often possess double-headed, monolayer spanning bolalipids, mixed with bilayer lipids, enabling them to survive in harsh environments. Here, using a minimal computational model for bolalipid membranes, we discover trade-offs when forming membranes. We find that membranes made out of flexible bolalipids resemble bilayer membranes as bolalipids exhibit conformational switch into U-shaped conformations to enable higher curvatures. Conversely, stiffer bolalipids, resembling those in extremophile archaea, take on straight conformations and form liquid membranes that are stiff, and prone to pore formation during membrane reshaping. Strikingly, we show how to achieve fluid bolalipid membranes that are both stable and flexible – by including small amounts of bilayer lipids, as archaea do. Our study explains how different organisms resolve trade-offs when generating membranes of desired material properties.}, author = {Santana de Freitas Amaral, Miguel and Frey, Felix F and Jiang, Xiuyun and Baum, Buzz and Šarić, Anđela}, booktitle = {bioRxiv}, title = {{Stability vs flexibility: Reshaping archaeal membranes in silico}}, doi = {10.1101/2024.10.18.619072}, year = {2024}, } @article{12708, abstract = {Self-organisation is the spontaneous emergence of spatio-temporal structures and patterns from the interaction of smaller individual units. Examples are found across many scales in very different systems and scientific disciplines, from physics, materials science and robotics to biology, geophysics and astronomy. Recent research has highlighted how self-organisation can be both mediated and controlled by confinement. Confinement is an action over a system that limits its units’ translational and rotational degrees of freedom, thus also influencing the system's phase space probability density; it can function as either a catalyst or inhibitor of self-organisation. Confinement can then become a means to actively steer the emergence or suppression of collective phenomena in space and time. Here, to provide a common framework and perspective for future research, we examine the role of confinement in the self-organisation of soft-matter systems and identify overarching scientific challenges that need to be addressed to harness its full scientific and technological potential in soft matter and related fields. By drawing analogies with other disciplines, this framework will accelerate a common deeper understanding of self-organisation and trigger the development of innovative strategies to steer it using confinement, with impact on, e.g., the design of smarter materials, tissue engineering for biomedicine and in guiding active matter.}, author = {Araújo, Nuno A.M. and Janssen, Liesbeth M.C. and Barois, Thomas and Boffetta, Guido and Cohen, Itai and Corbetta, Alessandro and Dauchot, Olivier and Dijkstra, Marjolein and Durham, William M. and Dussutour, Audrey and Garnier, Simon and Gelderblom, Hanneke and Golestanian, Ramin and Isa, Lucio and Koenderink, Gijsje H. and Löwen, Hartmut and Metzler, Ralf and Polin, Marco and Royall, C. Patrick and Šarić, Anđela and Sengupta, Anupam and Sykes, Cécile and Trianni, Vito and Tuval, Idan and Vogel, Nicolas and Yeomans, Julia M. and Zuriguel, Iker and Marin, Alvaro and Volpe, Giorgio}, issn = {1744-6848}, journal = {Soft Matter}, pages = {1695--1704}, publisher = {Royal Society of Chemistry}, title = {{Steering self-organisation through confinement}}, doi = {10.1039/d2sm01562e}, volume = {19}, year = {2023}, } @article{12756, abstract = {ESCRT-III family proteins form composite polymers that deform and cut membrane tubes in the context of a wide range of cell biological processes across the tree of life. In reconstituted systems, sequential changes in the composition of ESCRT-III polymers induced by the AAA–adenosine triphosphatase Vps4 have been shown to remodel membranes. However, it is not known how composite ESCRT-III polymers are organized and remodeled in space and time in a cellular context. Taking advantage of the relative simplicity of the ESCRT-III–dependent division system in Sulfolobus acidocaldarius, one of the closest experimentally tractable prokaryotic relatives of eukaryotes, we use super-resolution microscopy, electron microscopy, and computational modeling to show how CdvB/CdvB1/CdvB2 proteins form a precisely patterned composite ESCRT-III division ring, which undergoes stepwise Vps4-dependent disassembly and contracts to cut cells into two. These observations lead us to suggest sequential changes in a patterned composite polymer as a general mechanism of ESCRT-III–dependent membrane remodeling.}, author = {Hurtig, Fredrik and Burgers, Thomas C.Q. and Cezanne, Alice and Jiang, Xiuyun and Mol, Frank N. and Traparić, Jovan and Pulschen, Andre Arashiro and Nierhaus, Tim and Tarrason-Risa, Gabriel and Harker-Kirschneck, Lena and Löwe, Jan and Šarić, Anđela and Vlijm, Rifka and Baum, Buzz}, issn = {2375-2548}, journal = {Science Advances}, number = {11}, publisher = {American Association for the Advancement of Science}, title = {{The patterned assembly and stepwise Vps4-mediated disassembly of composite ESCRT-III polymers drives archaeal cell division}}, doi = {10.1126/sciadv.ade5224}, volume = {9}, year = {2023}, }