@article{10220, abstract = {We study conditions under which a finite simplicial complex K can be mapped to ℝd without higher-multiplicity intersections. An almost r-embedding is a map f: K → ℝd such that the images of any r pairwise disjoint simplices of K do not have a common point. We show that if r is not a prime power and d ≥ 2r + 1, then there is a counterexample to the topological Tverberg conjecture, i.e., there is an almost r-embedding of the (d +1)(r − 1)-simplex in ℝd. This improves on previous constructions of counterexamples (for d ≥ 3r) based on a series of papers by M. Özaydin, M. Gromov, P. Blagojević, F. Frick, G. Ziegler, and the second and fourth present authors. The counterexamples are obtained by proving the following algebraic criterion in codimension 2: If r ≥ 3 and if K is a finite 2(r − 1)-complex, then there exists an almost r-embedding K → ℝ2r if and only if there exists a general position PL map f: K → ℝ2r such that the algebraic intersection number of the f-images of any r pairwise disjoint simplices of K is zero. This result can be restated in terms of a cohomological obstruction and extends an analogous codimension 3 criterion by the second and fourth authors. As another application, we classify ornaments f: S3 ⊔ S3 ⊔ S3 → ℝ5 up to ornament concordance. It follows from work of M. Freedman, V. Krushkal and P. Teichner that the analogous criterion for r = 2 is false. We prove a lemma on singular higher-dimensional Borromean rings, yielding an elementary proof of the counterexample.}, author = {Avvakumov, Sergey and Mabillard, Isaac and Skopenkov, Arkadiy B. and Wagner, Uli}, issn = {1565-8511}, journal = {Israel Journal of Mathematics}, pages = {501–534 }, publisher = {Springer Nature}, title = {{Eliminating higher-multiplicity intersections. III. Codimension 2}}, doi = {10.1007/s11856-021-2216-z}, volume = {245}, year = {2021}, } @article{10221, abstract = {We prove that any deterministic matrix is approximately the identity in the eigenbasis of a large random Wigner matrix with very high probability and with an optimal error inversely proportional to the square root of the dimension. Our theorem thus rigorously verifies the Eigenstate Thermalisation Hypothesis by Deutsch (Phys Rev A 43:2046–2049, 1991) for the simplest chaotic quantum system, the Wigner ensemble. In mathematical terms, we prove the strong form of Quantum Unique Ergodicity (QUE) with an optimal convergence rate for all eigenvectors simultaneously, generalizing previous probabilistic QUE results in Bourgade and Yau (Commun Math Phys 350:231–278, 2017) and Bourgade et al. (Commun Pure Appl Math 73:1526–1596, 2020).}, author = {Cipolloni, Giorgio and Erdös, László and Schröder, Dominik J}, issn = {1432-0916}, journal = {Communications in Mathematical Physics}, number = {2}, pages = {1005–1048}, publisher = {Springer Nature}, title = {{Eigenstate thermalization hypothesis for Wigner matrices}}, doi = {10.1007/s00220-021-04239-z}, volume = {388}, year = {2021}, } @article{10222, abstract = {Consider a random set of points on the unit sphere in ℝd, which can be either uniformly sampled or a Poisson point process. Its convex hull is a random inscribed polytope, whose boundary approximates the sphere. We focus on the case d = 3, for which there are elementary proofs and fascinating formulas for metric properties. In particular, we study the fraction of acute facets, the expected intrinsic volumes, the total edge length, and the distance to a fixed point. Finally we generalize the results to the ellipsoid with homeoid density.}, author = {Akopyan, Arseniy and Edelsbrunner, Herbert and Nikitenko, Anton}, issn = {1944-950X}, journal = {Experimental Mathematics}, pages = {1--15}, publisher = {Taylor and Francis}, title = {{The beauty of random polytopes inscribed in the 2-sphere}}, doi = {10.1080/10586458.2021.1980459}, year = {2021}, } @article{10223, abstract = {Growth regulation tailors development in plants to their environment. A prominent example of this is the response to gravity, in which shoots bend up and roots bend down1. This paradox is based on opposite effects of the phytohormone auxin, which promotes cell expansion in shoots while inhibiting it in roots via a yet unknown cellular mechanism2. Here, by combining microfluidics, live imaging, genetic engineering and phosphoproteomics in Arabidopsis thaliana, we advance understanding of how auxin inhibits root growth. We show that auxin activates two distinct, antagonistically acting signalling pathways that converge on rapid regulation of apoplastic pH, a causative determinant of growth. Cell surface-based TRANSMEMBRANE KINASE1 (TMK1) interacts with and mediates phosphorylation and activation of plasma membrane H+-ATPases for apoplast acidification, while intracellular canonical auxin signalling promotes net cellular H+ influx, causing apoplast alkalinization. Simultaneous activation of these two counteracting mechanisms poises roots for rapid, fine-tuned growth modulation in navigating complex soil environments.}, author = {Li, Lanxin and Verstraeten, Inge and Roosjen, Mark and Takahashi, Koji and Rodriguez Solovey, Lesia and Merrin, Jack and Chen, Jian and Shabala, Lana and Smet, Wouter and Ren, Hong and Vanneste, Steffen and Shabala, Sergey and De Rybel, Bert and Weijers, Dolf and Kinoshita, Toshinori and Gray, William M. and Friml, Jiří}, issn = {14764687}, journal = {Nature}, keywords = {Multidisciplinary}, number = {7884}, pages = {273--277}, publisher = {Springer Nature}, title = {{Cell surface and intracellular auxin signalling for H+ fluxes in root growth}}, doi = {10.1038/s41586-021-04037-6}, volume = {599}, year = {2021}, } @article{10224, abstract = {We investigate the Fröhlich polaron model on a three-dimensional torus, and give a proof of the second-order quantum corrections to its ground-state energy in the strong-coupling limit. Compared to previous work in the confined case, the translational symmetry (and its breaking in the Pekar approximation) makes the analysis substantially more challenging.}, author = {Feliciangeli, Dario and Seiringer, Robert}, issn = {1432-0673}, journal = {Archive for Rational Mechanics and Analysis}, number = {3}, pages = {1835–1906}, publisher = {Springer Nature}, title = {{The strongly coupled polaron on the torus: Quantum corrections to the Pekar asymptotics}}, doi = {10.1007/s00205-021-01715-7}, volume = {242}, year = {2021}, } @inbook{10267, abstract = {Tropisms are among the most important growth responses for plant adaptation to the surrounding environment. One of the most common tropisms is root gravitropism. Root gravitropism enables the plant to anchor securely to the soil enabling the absorption of water and nutrients. Most of the knowledge related to the plant gravitropism has been acquired from the flowering plants, due to limited research in non-seed plants. Limited research on non-seed plants is due in large part to the lack of standard research methods. Here, we describe the experimental methods to evaluate gravitropism in representative non-seed plant species, including the non-vascular plant moss Physcomitrium patens, the early diverging extant vascular plant lycophyte Selaginella moellendorffii and fern Ceratopteris richardii. In addition, we introduce the methods used for statistical analysis of the root gravitropism in non-seed plant species.}, author = {Zhang, Yuzhou and Li, Lanxin and Friml, Jiří}, booktitle = {Plant Gravitropism}, editor = {Blancaflor, Elison B}, isbn = {978-1-0716-1676-5}, pages = {43--51}, publisher = {Springer Nature}, title = {{Evaluation of gravitropism in non-seed plants}}, doi = {10.1007/978-1-0716-1677-2_2}, volume = {2368}, year = {2021}, } @inbook{10268, abstract = {The analysis of dynamic cellular processes such as plant cytokinesis stands and falls with live-cell time-lapse confocal imaging. Conventional approaches to time-lapse imaging of cell division in Arabidopsis root tips are tedious and have low throughput. Here, we describe a protocol for long-term time-lapse simultaneous imaging of multiple root tips on a vertical-stage confocal microscope with automated root tracking. We also provide modifications of the basic protocol to implement this imaging method in the analysis of genetic, pharmacological or laser ablation wounding-mediated experimental manipulations. Our method dramatically improves the efficiency of cell division time-lapse imaging by increasing the throughput, while reducing the person-hour requirements of such experiments.}, author = {Hörmayer, Lukas and Friml, Jiří and Glanc, Matous}, booktitle = {Plant Cell Division}, isbn = {978-1-0716-1743-4}, issn = {1940-6029}, pages = {105--114}, publisher = {Humana Press}, title = {{Automated time-lapse imaging and manipulation of cell divisions in Arabidopsis roots by vertical-stage confocal microscopy}}, doi = {10.1007/978-1-0716-1744-1_6}, volume = {2382}, year = {2021}, } @article{10270, abstract = {Plants develop new organs to adjust their bodies to dynamic changes in the environment. How independent organs achieve anisotropic shapes and polarities is poorly understood. To address this question, we constructed a mechano-biochemical model for Arabidopsis root meristem growth that integrates biologically plausible principles. Computer model simulations demonstrate how differential growth of neighboring tissues results in the initial symmetry-breaking leading to anisotropic root growth. Furthermore, the root growth feeds back on a polar transport network of the growth regulator auxin. Model, predictions are in close agreement with in vivo patterns of anisotropic growth, auxin distribution, and cell polarity, as well as several root phenotypes caused by chemical, mechanical, or genetic perturbations. Our study demonstrates that the combination of tissue mechanics and polar auxin transport organizes anisotropic root growth and cell polarities during organ outgrowth. Therefore, a mobile auxin signal transported through immobile cells drives polarity and growth mechanics to coordinate complex organ development.}, author = {Marconi, Marco and Gallemi, Marçal and Benková, Eva and Wabnik, Krzysztof}, issn = {2050-084X}, journal = {eLife}, publisher = {eLife Sciences Publications}, title = {{A coupled mechano-biochemical model for cell polarity guided anisotropic root growth}}, doi = {10.7554/elife.72132}, volume = {10}, year = {2021}, } @article{10271, abstract = {Understanding interactions between antibiotics used in combination is an important theme in microbiology. Using the interactions between the antifolate drug trimethoprim and the ribosome-targeting antibiotic erythromycin in Escherichia coli as a model, we applied a transcriptomic approach for dissecting interactions between two antibiotics with different modes of action. When trimethoprim and erythromycin were combined, the transcriptional response of genes from the sulfate reduction pathway deviated from the dominant effect of trimethoprim on the transcriptome. We successfully altered the drug interaction from additivity to suppression by increasing the sulfate level in the growth environment and identified sulfate reduction as an important metabolic determinant that shapes the interaction between the two drugs. Our work highlights the potential of using prioritization of gene expression patterns as a tool for identifying key metabolic determinants that shape drug-drug interactions. We further demonstrated that the sigma factor-binding protein gene crl shapes the interactions between the two antibiotics, which provides a rare example of how naturally occurring variations between strains of the same bacterial species can sometimes generate very different drug interactions.}, author = {Qi, Qin and Angermayr, S. Andreas and Bollenbach, Mark Tobias}, issn = {1664-302X}, journal = {Frontiers in Microbiology}, keywords = {microbiology}, publisher = {Frontiers}, title = {{Uncovering Key Metabolic Determinants of the Drug Interactions Between Trimethoprim and Erythromycin in Escherichia coli}}, doi = {10.3389/fmicb.2021.760017}, volume = {12}, year = {2021}, } @article{10280, abstract = {Machines enabled the Industrial Revolution and are central to modern technological progress: A machine’s parts transmit forces, motion, and energy to one another in a predetermined manner. Today’s engineering frontier, building artificial micromachines that emulate the biological machinery of living organisms, requires faithful assembly and energy consumption at the microscale. Here, we demonstrate the programmable assembly of active particles into autonomous metamachines using optical templates. Metamachines, or machines made of machines, are stable, mobile and autonomous architectures, whose dynamics stems from the geometry. We use the interplay between anisotropic force generation of the active colloids with the control of their orientation by local geometry. This allows autonomous reprogramming of active particles of the metamachines to achieve multiple functions. It permits the modular assembly of metamachines by fusion, reconfiguration of metamachines and, we anticipate, a shift in focus of self-assembly towards active matter and reprogrammable materials.}, author = {Aubret, Antoine and Martinet, Quentin and Palacci, Jérémie A}, issn = {2041-1723}, journal = {Nature Communications}, number = {1}, publisher = {Springer Nature}, title = {{Metamachines of pluripotent colloids}}, doi = {10.1038/s41467-021-26699-6}, volume = {12}, year = {2021}, } @article{10281, abstract = {Mutations affecting mTOR or RAS signaling underlie defined syndromes (the so-called mTORopathies and RASopathies) with high risk for Autism Spectrum Disorder (ASD). These syndromes show a broad variety of somatic phenotypes including cancers, skin abnormalities, heart disease and facial dysmorphisms. Less well studied are the neuropsychiatric symptoms such as ASD. Here, we assess the relevance of these signalopathies in ASD reviewing genetic, human cell model, rodent studies and clinical trials. We conclude that signalopathies have an increased liability for ASD and that, in particular, ASD individuals with dysmorphic features and intellectual disability (ID) have a higher chance for disruptive mutations in RAS- and mTOR-related genes. Studies on rodent and human cell models confirm aberrant neuronal development as the underlying pathology. Human studies further suggest that multiple hits are necessary to induce the respective phenotypes. Recent clinical trials do only report improvements for comorbid conditions such as epilepsy or cancer but not for behavioral aspects. Animal models show that treatment during early development can rescue behavioral phenotypes. Taken together, we suggest investigating the differential roles of mTOR and RAS signaling in both human and rodent models, and to test drug treatment both during and after neuronal development in the available model systems}, author = {Vasic, Verica and Jones, Mattson S.O. and Haslinger, Denise and Knaus, Lisa and Schmeisser, Michael J. and Novarino, Gaia and Chiocchetti, Andreas G.}, issn = {2073-4425}, journal = {Genes}, number = {11}, publisher = {MDPI}, title = {{Translating the role of mtor-and ras-associated signalopathies in autism spectrum disorder: Models, mechanisms and treatment}}, doi = {10.3390/genes12111746}, volume = {12}, year = {2021}, } @article{10282, abstract = {Advanced transcriptome sequencing has revealed that the majority of eukaryotic genes undergo alternative splicing (AS). Nonetheless, little effort has been dedicated to investigating the functional relevance of particular splicing events, even those in the key developmental and hormonal regulators. Combining approaches of genetics, biochemistry and advanced confocal microscopy, we describe the impact of alternative splicing on the PIN7 gene in the model plant Arabidopsis thaliana. PIN7 encodes a polarly localized transporter for the phytohormone auxin and produces two evolutionarily conserved transcripts, PIN7a and PIN7b. PIN7a and PIN7b, differing in a four amino acid stretch, exhibit almost identical expression patterns and subcellular localization. We reveal that they are closely associated and mutually influence each other's mobility within the plasma membrane. Phenotypic complementation tests indicate that the functional contribution of PIN7b per se is minor, but it markedly reduces the prominent PIN7a activity, which is required for correct seedling apical hook formation and auxin-mediated tropic responses. Our results establish alternative splicing of the PIN family as a conserved, functionally relevant mechanism, revealing an additional regulatory level of auxin-mediated plant development.}, author = {Kashkan, Ivan and Hrtyan, Mónika and Retzer, Katarzyna and Humpolíčková, Jana and Jayasree, Aswathy and Filepová, Roberta and Vondráková, Zuzana and Simon, Sibu and Rombaut, Debbie and Jacobs, Thomas B. and Frilander, Mikko J. and Hejátko, Jan and Friml, Jiří and Petrášek, Jan and Růžička, Kamil}, issn = {1469-8137}, journal = {New Phytologist}, pages = {329--343}, publisher = {Wiley}, title = {{Mutually opposing activity of PIN7 splicing isoforms is required for auxin-mediated tropic responses in Arabidopsis thaliana}}, doi = {10.1111/nph.17792}, volume = {233}, year = {2021}, } @article{10283, abstract = {During the past decade, the scientific community and outside observers have noted a concerning lack of rigor and transparency in preclinical research that led to talk of a “reproducibility crisis” in the life sciences (Baker, 2016; Bespalov & Steckler, 2018; Heddleston et al, 2021). Various measures have been proposed to address the problem: from better training of scientists to more oversight to expanded publishing practices such as preregistration of studies. The recently published EQIPD (Enhancing Quality in Preclinical Data) System is, to date, the largest initiative that aims to establish a systematic approach for increasing the robustness and reliability of biomedical research (Bespalov et al, 2021). However, promoting a cultural change in research practices warrants a broad adoption of the Quality System and its underlying philosophy. It is here that academic Core Facilities (CF), research service providers at universities and research institutions, can make a difference. It is fair to assume that a significant fraction of published data originated from experiments that were designed, run, or analyzed in CFs. These academic services play an important role in the research ecosystem by offering access to cutting-edge equipment and by developing and testing novel techniques and methods that impact research in the academic and private sectors alike (Bikovski et al, 2020). Equipment and infrastructure are not the only value: CFs employ competent personnel with profound knowledge and practical experience of the specific field of interest: animal behavior, imaging, crystallography, genomics, and so on. Thus, CFs are optimally positioned to address concerns about the quality and robustness of preclinical research.}, author = {Restivo, Leonardo and Gerlach, Björn and Tsoory, Michael and Bikovski, Lior and Badurek, Sylvia and Pitzer, Claudia and Kos-Braun, Isabelle C. and Mausset-Bonnefont, Anne Laure Mj and Ward, Jonathan and Schunn, Michael and Noldus, Lucas P.J.J. and Bespalov, Anton and Voikar, Vootele}, issn = {1469-3178}, journal = {EMBO Reports}, publisher = {EMBO Press}, title = {{Towards best practices in research: Role of academic core facilities}}, doi = {10.15252/embr.202153824}, volume = {22}, year = {2021}, } @article{10285, abstract = {We study the overlaps between right and left eigenvectors for random matrices of the spherical ensemble, as well as truncated unitary ensembles in the regime where half of the matrix at least is truncated. These two integrable models exhibit a form of duality, and the essential steps of our investigation can therefore be performed in parallel. In every case, conditionally on all eigenvalues, diagonal overlaps are shown to be distributed as a product of independent random variables with explicit distributions. This enables us to prove that the scaled diagonal overlaps, conditionally on one eigenvalue, converge in distribution to a heavy-tail limit, namely, the inverse of a γ2 distribution. We also provide formulae for the conditional expectation of diagonal and off-diagonal overlaps, either with respect to one eigenvalue, or with respect to the whole spectrum. These results, analogous to what is known for the complex Ginibre ensemble, can be obtained in these cases thanks to integration techniques inspired from a previous work by Forrester & Krishnapur.}, author = {Dubach, Guillaume}, issn = {1083-6489}, journal = {Electronic Journal of Probability}, publisher = {Institute of Mathematical Statistics}, title = {{On eigenvector statistics in the spherical and truncated unitary ensembles}}, doi = {10.1214/21-EJP686}, volume = {26}, year = {2021}, } @article{10290, abstract = {A precise quantitative description of the ultrastructural characteristics underlying biological mechanisms is often key to their understanding. This is particularly true for dynamic extra- and intracellular filamentous assemblies, playing a role in cell motility, cell integrity, cytokinesis, tissue formation and maintenance. For example, genetic manipulation or modulation of actin regulatory proteins frequently manifests in changes of the morphology, dynamics, and ultrastructural architecture of actin filament-rich cell peripheral structures, such as lamellipodia or filopodia. However, the observed ultrastructural effects often remain subtle and require sufficiently large datasets for appropriate quantitative analysis. The acquisition of such large datasets has been enabled by recent advances in high-throughput cryo-electron tomography (cryo-ET) methods. This also necessitates the development of complementary approaches to maximize the extraction of relevant biological information. We have developed a computational toolbox for the semi-automatic quantification of segmented and vectorized filamentous networks from pre-processed cryo-electron tomograms, facilitating the analysis and cross-comparison of multiple experimental conditions. GUI-based components simplify the processing of data and allow users to obtain a large number of ultrastructural parameters describing filamentous assemblies. We demonstrate the feasibility of this workflow by analyzing cryo-ET data of untreated and chemically perturbed branched actin filament networks and that of parallel actin filament arrays. In principle, the computational toolbox presented here is applicable for data analysis comprising any type of filaments in regular (i.e. parallel) or random arrangement. We show that it can ease the identification of key differences between experimental groups and facilitate the in-depth analysis of ultrastructural data in a time-efficient manner.}, author = {Dimchev, Georgi A and Amiri, Behnam and Fäßler, Florian and Falcke, Martin and Schur, Florian KM}, issn = {1047-8477}, journal = {Journal of Structural Biology}, keywords = {Structural Biology}, number = {4}, publisher = {Elsevier }, title = {{Computational toolbox for ultrastructural quantitative analysis of filament networks in cryo-ET data}}, doi = {10.1016/j.jsb.2021.107808}, volume = {213}, year = {2021}, } @phdthesis{10293, abstract = {Indirect reciprocity in evolutionary game theory is a prominent mechanism for explaining the evolution of cooperation among unrelated individuals. In contrast to direct reciprocity, which is based on individuals meeting repeatedly, and conditionally cooperating by using their own experiences, indirect reciprocity is based on individuals’ reputations. If a player helps another, this increases the helper’s public standing, benefitting them in the future. This lets cooperation in the population emerge without individuals having to meet more than once. While the two modes of reciprocity are intertwined, they are difficult to compare. Thus, they are usually studied in isolation. Direct reciprocity can maintain cooperation with simple strategies, and is robust against noise even when players do not remember more than their partner’s last action. Meanwhile, indirect reciprocity requires its successful strategies, or social norms, to be more complex. Exhaustive search previously identified eight such norms, called the “leading eight”, which excel at maintaining cooperation. However, as the first result of this thesis, we show that the leading eight break down once we remove the fundamental assumption that information is synchronized and public, such that everyone agrees on reputations. Once we consider a more realistic scenario of imperfect information, where reputations are private, and individuals occasionally misinterpret or miss observations, the leading eight do not promote cooperation anymore. Instead, minor initial disagreements can proliferate, fragmenting populations into subgroups. In a next step, we consider ways to mitigate this issue. We first explore whether introducing “generosity” can stabilize cooperation when players use the leading eight strategies in noisy environments. This approach of modifying strategies to include probabilistic elements for coping with errors is known to work well in direct reciprocity. However, as we show here, it fails for the more complex norms of indirect reciprocity. Imperfect information still prevents cooperation from evolving. On the other hand, we succeeded to show in this thesis that modifying the leading eight to use “quantitative assessment”, i.e. tracking reputation scores on a scale beyond good and bad, and making overall judgments of others based on a threshold, is highly successful, even when noise increases in the environment. Cooperation can flourish when reputations are more nuanced, and players have a broader understanding what it means to be “good.” Finally, we present a single theoretical framework that unites the two modes of reciprocity despite their differences. Within this framework, we identify a novel simple and successful strategy for indirect reciprocity, which can cope with noisy environments and has an analogue in direct reciprocity. We can also analyze decision making when different sources of information are available. Our results help highlight that for sustaining cooperation, already the most simple rules of reciprocity can be sufficient.}, author = {Schmid, Laura}, issn = {2663-337X}, pages = {171}, publisher = {Institute of Science and Technology Austria}, title = {{Evolution of cooperation via (in)direct reciprocity under imperfect information}}, doi = {10.15479/at:ista:10293}, year = {2021}, } @article{10299, abstract = {Turbulence generally arises in shear flows if velocities and hence, inertial forces are sufficiently large. In striking contrast, viscoelastic fluids can exhibit disordered motion even at vanishing inertia. Intermediate between these cases, a state of chaotic motion, “elastoinertial turbulence” (EIT), has been observed in a narrow Reynolds number interval. We here determine the origin of EIT in experiments and show that characteristic EIT structures can be detected across an unexpectedly wide range of parameters. Close to onset, a pattern of chevron-shaped streaks emerges in qualitative agreement with linear and weakly nonlinear theory. However, in experiments, the dynamics remain weakly chaotic, and the instability can be traced to far lower Reynolds numbers than permitted by theory. For increasing inertia, the flow undergoes a transformation to a wall mode composed of inclined near-wall streaks and shear layers. This mode persists to what is known as the “maximum drag reduction limit,” and overall EIT is found to dominate viscoelastic flows across more than three orders of magnitude in Reynolds number.}, author = {Choueiri, George H and Lopez Alonso, Jose M and Varshney, Atul and Sankar, Sarath and Hof, Björn}, issn = {1091-6490}, journal = {Proceedings of the National Academy of Sciences}, keywords = {multidisciplinary, elastoinertial turbulence, viscoelastic flows, elastic instability, drag reduction}, number = {45}, publisher = {National Academy of Sciences}, title = {{Experimental observation of the origin and structure of elastoinertial turbulence}}, doi = {10.1073/pnas.2102350118}, volume = {118}, year = {2021}, } @article{10301, abstract = {De novo protein synthesis is required for synapse modifications underlying stable memory encoding. Yet neurons are highly compartmentalized cells and how protein synthesis can be regulated at the synapse level is unknown. Here, we characterize neuronal signaling complexes formed by the postsynaptic scaffold GIT1, the mechanistic target of rapamycin (mTOR) kinase, and Raptor that couple synaptic stimuli to mTOR-dependent protein synthesis; and identify NMDA receptors containing GluN3A subunits as key negative regulators of GIT1 binding to mTOR. Disruption of GIT1/mTOR complexes by enhancing GluN3A expression or silencing GIT1 inhibits synaptic mTOR activation and restricts the mTOR-dependent translation of specific activity-regulated mRNAs. Conversely, GluN3A removal enables complex formation, potentiates mTOR-dependent protein synthesis, and facilitates the consolidation of associative and spatial memories in mice. The memory enhancement becomes evident with light or spaced training, can be achieved by selectively deleting GluN3A from excitatory neurons during adulthood, and does not compromise other aspects of cognition such as memory flexibility or extinction. Our findings provide mechanistic insight into synaptic translational control and reveal a potentially selective target for cognitive enhancement.}, author = {Conde-Dusman, María J and Dey, Partha N and Elía-Zudaire, Óscar and Garcia Rabaneda, Luis E and García-Lira, Carmen and Grand, Teddy and Briz, Victor and Velasco, Eric R and Andero Galí, Raül and Niñerola, Sergio and Barco, Angel and Paoletti, Pierre and Wesseling, John F and Gardoni, Fabrizio and Tavalin, Steven J and Perez-Otaño, Isabel}, issn = {2050-084X}, journal = {eLife}, keywords = {general immunology and microbiology, general biochemistry, genetics and molecular biology, general medicine, general neuroscience}, publisher = {eLife Sciences Publications}, title = {{Control of protein synthesis and memory by GluN3A-NMDA receptors through inhibition of GIT1/mTORC1 assembly}}, doi = {10.7554/elife.71575}, volume = {10}, year = {2021}, } @phdthesis{10303, abstract = {Nitrogen is an essential macronutrient determining plant growth, development and affecting agricultural productivity. Root, as a hub that perceives and integrates local and systemic signals on the plant’s external and endogenous nitrogen resources, communicates with other plant organs to consolidate their physiology and development in accordance with actual nitrogen balance. Over the last years, numerous studies demonstrated that these comprehensive developmental adaptations rely on the interaction between pathways controlling nitrogen homeostasis and hormonal networks acting globally in the plant body. However, molecular insights into how the information about the nitrogen status is translated through hormonal pathways into specific developmental output are lacking. In my work, I addressed so far poorly understood mechanisms underlying root-to-shoot communication that lead to a rapid re-adjustment of shoot growth and development after nitrate provision. Applying a combination of molecular, cell, and developmental biology approaches, genetics and grafting experiments as well as hormonal analytics, I identified and characterized an unknown molecular framework orchestrating shoot development with a root nitrate sensory system. }, author = {Abualia, Rashed}, issn = {2663-337X}, pages = {139}, publisher = {Institute of Science and Technology Austria}, title = {{Role of hormones in nitrate regulated growth}}, doi = {10.15479/at:ista:10303}, year = {2021}, } @phdthesis{10307, abstract = {Bacteria-host interactions represent a continuous trade-off between benefit and risk. Thus, the host immune response is faced with a non-trivial problem – accommodate beneficial commensals and remove harmful pathogens. This is especially difficult as molecular patterns, such as lipopolysaccharide or specific surface organelles such as pili, are conserved in both, commensal and pathogenic bacteria. Type 1 pili, tightly regulated by phase variation, are considered an important virulence factor of pathogenic bacteria as they facilitate invasion into host cells. While invasion represents a de facto passive mechanism for pathogens to escape the host immune response, we demonstrate a fundamental role of type 1 pili as active modulators of the innate and adaptive immune response.}, author = {Tomasek, Kathrin}, issn = {2663-337X}, pages = {73}, publisher = {Institute of Science and Technology Austria}, title = {{Pathogenic Escherichia coli hijack the host immune response}}, doi = {10.15479/at:ista:10307}, year = {2021}, }