bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nucleation of the destruction complex on the centrosome accelerates degradation of β-catenin and regulates Wnt signal transmission
Authors: Lach Ryan S. , Qiu Chongxu , Kajbaf Erfan Zeyaei , Baxter Naomi , Han Dasol , Wang Alex , Lock Hannah , Chirikian Orlando , Pruitt Beth , Wilson Maxwell Z. 
Published: February 2022

AbstractWnt signal transduction is mediated by a protein assembly called the Destruction Complex (DC) made from scaffold proteins and kinases that are essential for transducing extracellular Wnt ligand concentrations to changes in nuclear β-catenin, the pathway’s transcriptional effector. Recently, DC scaffold proteins have been shown to undergo liquid-liquid phase separation in vivo and in vitro providing evidence for a mesoscale organization of the DC. However, the mesoscale organization of DC at endogenous expression levels and how that organization could play a role in β-catenin processing is unknown. Here we find that the native mesoscale structure is a dynamic biomolecular condensate nucleated by the centrosome. Through a combination of advanced microscopy, CRISPR-engineered custom fluorescent tags, finite element simulations, and optogenetic tools, that allow for independent manipulation of the biophysical parameters that drive condensate formation, we find that a function of DC nucleation by the centrosome is to drive efficient processing of β-catenin by co-localizing DC components to a single reaction hub. We demonstrate that simply increasing the concentration of a single DC kinase onto the centrosome controls β-catenin processing. This simple change in localization completely alters the fate of the Wnt-driven human embryonic stem cell differentiation to mesoderm. Our findings demonstrate the role of nucleators in dynamically controlling the activities of biomolecular condensates and suggest a tight integration between cell cycle progression and Wnt signal transduction.
Insect asynchronous flight requires neural circuit de-synchronization by electrical synapses
Authors: Hürkey Silvan , Niemeyer Nelson , Schleimer Jan-Hendrik , Ryglewski Stefanie , Schreiber Susanne , Duch Carsten 
Published: February 2022

AbstractDespite profound mechanistic insight into motor pattern generation, for asynchronous insect flight – the most prevalent form of flight employed by >600.000 species – architecture and function of the underlying central pattern generating (CPG) neural network remain elusive. Combining electro- and optophysiology, Drosophila genetics, and mathematical modelling, we uncover a miniaturized circuit solution of motoneurons interconnected by electrical synapses that, contrary to doctrine, serve to de-synchronize network activity. This minimal gap-junctional motoneuron network suffices to translate unpatterned premotor input into stereotyped firing sequences which are conserved across species and generate stable wingbeat power. Mechanistically, network de-synchronization requires weak electrical coupling in conjunction with specific postsynaptic excitability dynamics, revealing an unexpected, generic feature in the control of neural circuit dynamics by electrical synapses.One Sentence SummaryElectrical synapses de-synchronize neural network firing to enable stable wingbeat power during insect flight.
RNase H-based analysis of synthetic mRNA 5’ cap incorporation
Authors: Chan Siu-Hong , Whipple Joseph M. , Dai Nan , Kelley Theresa M. , Withers Kathryn , Tzertzinis George , Corrêa Ivan R , Robb G. Brett 
Published: February 2022

AbstractAdvances in mRNA synthesis and lipid nanoparticles technologies have helped make mRNA therapeutics and vaccines a reality. The 5’ cap structure is a crucial modification required to functionalize synthetic mRNA for efficient protein translation in vivo and evasion of cellular innate immune responses. The extent of 5’ cap incorporation is one of the critical quality attributes in mRNA manufacturing. RNA cap analysis involves multiple steps: generation of pre-defined short fragments from the 5’ end of the kilobase-long synthetic mRNA molecules using RNase H, a ribozyme or a DNAzyme, enrichment of the 5’ cleavage products, and LC-MS intact mass analysis. In this communication, we describe 1) a framework to design site-specific RNA cleavage using RNase H; 2) a method to fluorescently label the RNase H cleavage fragments for more accessible readout methods such as gel electrophoresis or high-throughput capillary electrophoresis; 3) a simplified method for post-RNase H purification using desthiobiotinylated oligonucleotides and streptavidin magnetic beads followed by elution using water. By providing a design framework for RNase H-based RNA 5’ cap analysis using less resource-intensive analytical methods, we hope to make RNA cap analysis more accessible to the scientific community.
A natural fusion of flavodiiron, rubredoxin, and NADH:rubredoxin oxidoreductase domains is the highly efficient water-forming oxidase of T. vaginalis
Authors: Abdulaziz Evana N. , Bell Tristan A. , Rashid Bazlur , Heacock Mina L. , Skinner Owen S. , Yaseen Mohammad A. , Chao Luke H. , Mootha Vamsi K. , Pierik Antonio J. , Cracan Valentin 
Published: February 2022

AbstractMicroaerophilic pathogens such as Giardia lamblia and Trichomonas vaginalis have robust oxygen consumption systems to detoxify oxygen and maintain the intracellular redox balance. This oxygen consumption is a result of the H2O-forming NADH oxidase activity of two distinct flavin-containing systems: H2O-forming NADH oxidases (NOXes) and multicomponent flavodiiron proteins (FDPs). Both systems are not membrane-bound and recycle NADH into oxidized NAD+ while simultaneously removing O2 from the local environment, making them crucial for the survival of human microaerophilic pathogens. In this study, using bioinformatic and biochemical analysis, we show that T. vaginalis lacks a NOX-like enzyme, and instead harbors three proteins that are very close in their amino acid sequence and represent a natural fusion between N-terminal FDP, central rubredoxin and C-terminal NADH:rubredoxin oxidoreductase domains. We demonstrate that this natural fusion protein with fully populated flavin redox centers unlike a “stand-alone” FDP (also present in T. vaginalis), directly accepts reducing equivalents of NADH to catalyze the four-electron reduction of O2 to water within a single polypeptide and with an extremely high turnover. Using single particle electron cryo-microscopy (cryo-EM) we present structural insight into the spatial organization of the FDP core within this multidomain fusion protein. Our studies represent an important addition to our understanding of systems that allow human protozoan parasites to maintain their optimal redox balance and survive transient exposure to oxic conditions.
Chemically modified dsRNA induces RNAi effects in insects in vitro and in vivo: A potential new tool for improving RNA-based plant protection
Authors: Howard John D. , Beghyn Myriam , Dewulf Nathalie , De Vos Yves , Philips Annelies , Portwood David , Kilby Peter M. , Oliver Duncan , Maddelein Wendy , Brown Stephen , Dickman Mark J. 
Published: February 2022

ABSTRACTGlobal agriculture loses over $100 billion of produce annually to crop pests such as insects. Many of these crop pests either have no current means of control or have developed resistance against chemical pesticides. Long dsRNAs are capable of inducing RNA interference (RNAi) in insects and are emerging as novel highly selective alternatives for sustainable insect management strategies. However, there are significant challenges associated with RNAi efficacy in insects. In this study, we synthesised a range of chemically modified long dsRNA in an approach to improve nuclease resistance and RNAi efficacy in insects. The results showed that dsRNA containing phosphorothioate modifications demonstrated increased resistance to southern green stink bug saliva nucleases. Phosphorothioate and 2’-fluoro modified dsRNA also demonstrated increased resistance to degradation by soil nucleases and increased RNAi efficacy in Drosophila melanogaster cell cultures. In live insects, chemically modified long dsRNA successfully resulted in mortality in both stink bug and corn rootworm. The results provide further mechanistic insight of RNAi efficacy dependence on modifications in the sense or antisense strand of the dsRNA in insects and demonstrate for the first time that RNAi can successfully be triggered by chemically modified long dsRNA in insect cells or live insects.
SRSF1 as a novel interacting partner for IFITM1/3 unravels the emergent role of IFITM1/3 mediating protein expression
Authors: Gómez-Herranz Maria , Faktor Jakub , Mayordomo Marcos Yébenes , Pilch Magdalena , Hernychova Lenka , Ball Kathryn L. , Vojtesek Borivoj , Hupp Ted R. , Kote Sachin 
Published: February 2022

AbstractIFITM proteins play a role in cancer cell progression through undefined mechanisms. Here, we propose an emergent role of IFITM1/3 regulating protein synthesis. SBP-tagged IFITM1 protein was used to identify an association of IFITM1 protein with the cytosolic isoform of SRSF1 that transports mRNA to the ribosome. This cytosolic association was confirmed in situ using proximity ligation assays for SRSF1 and IFITM1/3, suggesting a role associated with translation. Accordingly, IFITM1/3 were shown to interact with HLA-B mRNA in response to IFNγ stimulation using RNA-protein proximity ligation assays. In addition, shotgun RNA sequencing in IFITM1/IFITM3 null cells and wt-SiHa cells indicated that reduced HLA-B gene expression does not account for lowered HLA-B protein synthesis in response to IFNγ. Furthermore, ribosome profiling using sucrose gradient sedimentation identified a reduction in 80S ribosomal fraction an IFITM1/IFITM3 null cells compared to their wild-type counterpart, partially reverted by IFITM1/3 complementation. Our data all together link the binding of IFITM1/3 proteins to HLA-B mRNA and SRSF1 as a mechanism to catalyze the synthesis of target proteins, suggesting an RNA chaperonin role for IFITM1/3 proteins.SignificanceIFITMs are widely studied for their role in inhibiting viruses, and multiple studies have associated IFITMs with cancer progression. However, mechanistic insights are not well understood. Our study proposes that IFITMs have a role regulating protein synthesis, a pivotal function highly relevant for viral infection and cancer progression. Our results suggest that IFITM1/3 is present in the ribosomal fraction and regulates particular protein expression; among them, we identified HLA-B. Changes in HLA-B expression could impact the presentation and recognition of oncogenic antigens on the cell surface by cytotoxic T cells and, ultimately, limit tumor cell eradication. In addition, the role of IFITMs mediating protein translation is relevant, as has the potential of regulating the expression of viral and oncogenic proteins.
Effects of calorie restriction on reactive oxygen species production by mitochondrial reverse electron transport, mitochondrial permeability transition pore, and beta-adrenergic stimulation during cardiac hypertrophy
Authors: Lucas Aline Maria Brito , Palacio Plinio Bezerra , Cunha Pedro Lourenzo Oliveira , Facundo Heberty Tarso 
Published: February 2022

AbstractCalorie restriction is a nutritional intervention that reproducibly protects against the maladaptive consequences of cardiovascular diseases. Pathological cardiac hypertrophy leads to cellular growth, dysfunction (with mitochondrial dysregulation), and oxidative stress. The mechanisms behind the cardiovascular protective effects of calorie restriction are still under investigation. In this study, we addressed the impact of calorie restriction on mitochondria, oxidative stress markers, and β-adrenergic signaling during cardiac hypertrophy. This dietetic intervention prevented cardiac protein elevation, decreased atrial natriuretic peptide levels, and blocked the increase in heart weight per tibia length index seen in isoproterenol-induced cardiac hypertrophy. Our data suggest that inhibition of cardiac pathological growth by calorie restriction is accompanied by a lower mitochondrial reactive oxygen species formation and improved mitochondrial content. We also found that superoxide dismutase and glutathione peroxidase activities negatively correlate with cardiac hypertrophy. Calorie restriction also attenuated the opening of the Ca2+-induced mitochondrial permeability transition pore in mitochondria isolated from isoproterenol-treated mice. Isoproterenol (a β-agonist) increases cardiac rate (chronotropic response) and force of contraction (inotropic response). Given the nature of cardiac hypertrophy induction by isoproterenol, we tested whether calorie restriction could change the cardiac β-adrenergic sensitivity. Using isolated rat hearts in a langendorff system, we found that calorie restriction mice (similar to controls) have preserved β-adrenergic signaling. On the flipside, hypertrophic hearts (treated for seven days with isoproterenol) were insensitive to β-adrenergic activation using isoproterenol (50 nM). Despite protecting against cardiac hypertrophy, calorie restriction did not alter the lack of responsiveness to isoproterenol of isolated hearts harvested from isoproterenol-treated rats. These results suggest (through a series of mitochondrial, oxidative stress, and cardiac hemodynamic studies) that calorie restriction possesses beneficial effects against hypertrophic cardiomyopathy. However, it may lack effects on some of the hypertrophic consequences, such as β-adrenergic signaling repression.
AlphaFold accurately predicts distinct conformations based on oligomeric state of a de novo designed protein
Authors: Cummins Matthew C. , Jacobs Tim M. , Teets Frank D. , DiMaio Frank , Tripathy Ashutosh , Kuhlman Brian 
Published: February 2022

ABSTRACTUsing the molecular modeling program Rosetta, we designed a de novo protein, called SEWN0.1, that binds the heterotrimeric G protein Gαq. The design is helical, well-folded, and primarily monomeric in solution at a concentration of 10 uM. However, when we solved the crystal structure of SEWN0.1, we observed a dimer in a conformation incompatible with binding Gαq. Unintentionally, we had designed a protein that adopts alternate conformations depending on its oligomeric state. Recently, there has been tremendous progress in the field of protein structure prediction as new methods in artificial intelligence have been used to predict structures with high accuracy. We were curious if the structure prediction method AlphaFold could predict the structure of SEWN0.1 and if the prediction depended on oligomeric state. When AlphaFold was used to predict the structure of monomeric SEWN0.1, it produced a model that resembles the Rosetta design model and is compatible with binding Gαq, but when used to predict the structure of a dimer, it predicted a conformation that closely resembles the SEWN0.1 crystal structure. AlphaFold’s ability to predict multiple conformations for a single protein sequence should be useful for engineering protein switches.
Nutrient gradients mediate creation of highly resistant layers in structured microbial populations during antibiotic exposures
Authors: Stevanovic Mirjana , Boukéké-Lesplulier Thomas , Hupe Lukas , Hasty Jeff , Bittihn Philip , Schultz Daniel 
Published: February 2022

AbstractAntibiotic treatments often fail to eliminate bacterial populations due to heterogeneity in how individual cells respond to the drug. In structured bacterial populations such as biofilms, bacterial metabolism and environmental transport processes lead to an emergent phenotypic structure and self-generated nutrient gradients towards the interior of the colony, which can affect cell growth, gene expression and susceptibility to the drug. Even in single cells, survival depends on a dynamic interplay between the drug’s action and the expression of resistance genes. How expression of resistance is coordinated across populations in the presence of such spatiotemporal environmental coupling remains elusive. Using a custom microfluidic device, we observe the response of spatially extended microcolonies of tetracycline-resistant E. coli to precisely defined dynamic drug regimens. We find an intricate interplay between drug-induced changes in cell growth and growth-dependent expression of resistance genes, resulting in the redistribution of nutrients and the reorganization of growth patterns. This dynamic environmental feedback affects the regulation of drug resistance differently across the colony, generating dynamic phenotypic structures that maintain colony growth during exposure to high drug concentrations and increase population-level resistance to subsequent exposures. A mathematical model linking metabolism and the regulation of gene expression is able to capture the main features of spatiotemporal colony dynamics. Uncovering the fundamental principles that govern collective mechanisms of antibiotic resistance in spatially extended populations will allow the design of optimal drug regimens to counteract them.
Phase separating RNA binding proteins form heterogeneous distributions of clusters in subsaturated solutions
Authors: Kar Mrityunjoy , Dar Furqan , Welsh Timothy J. , Vogel Laura , Kühnemuth Ralf , Majumdar Anupa , Krainer Georg , Franzmann Titus M. , Alberti Simon , Seidel Claus A. M. , Knowles Tuomas P.J. , Hyman Anthony A. , Pappu Rohit V. 
Published: February 2022

AbstractMacromolecular phase separation is thought to be one of the processes that drives the formation of membraneless biomolecular condensates in cells. The dynamics of phase separation, especially at low endogenous concentrations found in cells, are thought to follow the tenets of classical nucleation theory describing a sharp transition between a dense phase and a dilute phase characterized by dispersed monomers. Here, we usedin vitrobiophysical studies to study subsaturated solutions of phase separating RNA binding proteins with intrinsically disordered prion like domains (PLDs) and RNA binding domains (RBDs). Surprisingly, we find that subsaturated solutions are characterized by heterogeneous distributions of clusters comprising tens to hundreds of molecules. These clusters also include low abundance mesoscale species that are several hundreds of nanometers in diameter. Our results show that cluster formation in subsaturated solutions and phase separation in supersaturated solutions are strongly coupled via sequence-encoded interactions. Interestingly, however, cluster formation and phase separation can be decoupled from one another using solutes that impact the solubilities of phase separating proteins. They can also be decoupled by specific types of mutations. Overall, our findings implicate the presence of distinct, sequence-specific energy scales that contribute to the overall phase behaviors of RNA binding proteins. We discuss our findings in the context of theories of associative polymers.Significance StatementMembraneless biomolecular condensates are molecular communities with distinct compositional preferences and functions. Considerable attention has focused on phase separation as the process that gives rise to condensates. Here, we show that subsaturated solutions of RNA binding proteins form heterogeneous distributions of clusters in subsaturated solutions. The formation of clusters in subsaturated solutions and condensates in supersaturated solution are coupled through sequence-specific interactions. Given the low endogenous concentrations of phase separating proteins, our findings suggest that clusters in subsaturated conditions might be of functional relevance in cells.
Effects of Big Five personality traits and market mavenship on consumers' intention to spread word-of-mouth in the art context
Authors: Chieffi Verdiana , Pichierri Marco , Peluso Alessandro M. , Collu Cristiana , Guido Gianluigi 
Published: February 2022

PurposeThis study investigates the transmission of art-related aspects (i.e. art products or services and people's experiences at museums) via word-of-mouth (WOM) from a personality perspective. Specifically, the study explores the effects of the Big Five personality traits (based on the five-factor model) and market mavenship (i.e. the propensity to provide general marketplace and shopping information) on intention to spread WOM in the art context.Design/methodology/approachData were gathered through two field surveys, conducted via a structured questionnaire and analyzed using multiple regression analysis.FindingsResults indicate that extraversion is the only Big Five personality trait that increases WOM intention (e.g. by talking to others about a visit to a museum). Market mavenship also increases such an intention (e.g. by talking to others about art services).Practical implicationsThe study's findings could motivate arts managers to formulate and/or refine segmentation strategies around their consumers' personality traits, since these variables may differently motivate them to spread art-related WOM. The findings may also help companies and institutions operating in the art industry to design communication strategies oriented around their consumers' personality type to appropriately connect with different groups of customers based on their innate human drives.Originality/valueThis is the first study to assess the effects of Big Five personality traits and market mavenship on WOM intention in the art context, thus expanding scholarly understanding of psychological drivers behind arts-related WOM.
Sustainability teaching using case-based debates
Authors: Georgallis Panikos , Bruijn Kayleigh 
Published: February 2022

Purpose
Given today’s pressing societal challenges, business schools are increasingly expected to incorporate sustainability in their curricula. Yet, while research on corporate sustainability is on the rise, there is less innovation in teaching methods as most institutions rely on traditional methods to teach sustainability in the classroom. This paper aims to present the case-based debate as an appropriate teaching method for exposing students to the complexity of business sustainability issues.

Design/methodology/approach
The pedagogical background of the traditional case method and the debate method have been analyzed to provide an integrated understanding of the benefits of combining the two in the case-based debate. Building on the authors’ experiences from using case-based debates in the classroom, the paper describes what a case-debate is and how it can be implemented.

Findings
The paper offers a practical tool that can be used to teach sustainability in business schools and other educational institutions. Case-based debates can elicit active participation, support the development of students’ critical thinking skills and improve reflexivity by compelling students to seriously and actively engage with opposing viewpoints on a given issue.

Originality/value
This paper presents a hybrid approach for sustainability teaching that combines the benefits of the traditional case method with those of an in-class debate. The case-based debate method has received little attention in educational research and business sustainability teaching practice but can serve multiple teaching objectives relevant to sustainability teaching.