bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural insights into crista junction formation by the Mic60-Mic19 complex
Authors: Bock-Bierbaum Tobias , Funck Kathrin , Wollweber Florian , Lisicki Elisa , Laborenz Janina , Noel Jeffrey K. , Hessenberger Manuel , von der Malsburg Alexander , von der Malsburg Karina , Bernert Carola , Kunz Séverine , Riedel Dietmar , Lilie Hauke , Jakobs Stefan , van der Laan Martin , Daumke Oliver 
Published: March 2022

AbstractMitochondrial cristae membranes are the oxidative phosphorylation sites in cells. Crista junctions (CJs) form the highly curved neck regions of cristae and are thought to function as selective entry gates into the cristae space. Little is known about how CJs are generated and maintained. We show that the central coiled-coil domain of the mitochondrial contact and cristae organizing system (MICOS) subunit Mic60 forms an elongated, bow tie-shaped tetrameric assembly. Mic19 promotes Mic60 tetramerization via a conserved interface between the Mic60 mitofilin and Mic19 CHCH domains. Dimerization of mitofilin domains exposes a crescent-shaped membrane-binding site with convex curvature tailored to interact with curved CJ necks. Our study suggests that the Mic60-Mic19 subcomplex transverses CJs as a molecular strut, thereby controlling CJ architecture and function.
Ancestral origins are associated with SARS-CoV-2 susceptibility and protection in a Florida patient population
Authors: Shen Yiran , Khatri Bhuwan , Rananaware Santosh , Li Danmeng , Ostrov David A. , Jain Piyush K , Lessard Christopher J. , Nguyen Cuong Q. 
Published: March 2022

AbstractCOVID-19 is caused by severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The severity of COVID-19 is highly variable and related to known (e.g., age, obesity, immune deficiency) and unknown risk factors. The widespread clinical symptoms encompass a large group of asymptomatic COVID-19 patients, raising a crucial question regarding genetic susceptibility, e.g., whether individual differences in immunity play a role in patient symptomatology and how much human leukocyte antigen (HLA) contributes to this. To reveal genetic determinants of susceptibility to COVID-19 severity in the population and further explore potential immune-related factors, we performed a genome-wide association study on 284 confirmed COVID-19 patients (cases) and 95 healthy individuals (controls). We compared cases and controls of European (EUR) ancestry and African American (AFR) ancestry separately. We identified two loci on chromosomes 5q32 and 11p12, which reach the significance threshold of suggestive association (p<1×10-5 threshold adjusted for multiple trait testing) and are associated with the COVID-19 susceptibility in the European ancestry (index rs17448496: odds ratio [OR] = 0.173; 95% confidence interval [CI], 0.08–0.36 for G allele; p=5.15× 10-5 and index rs768632395: OR = 0.166; 95% CI, 0.07–0.35 for A allele; p= 4.25×10-6, respectively), which were associated with two genes, PPP2R2B at 5q32, and LRRC4C at 11p12, respectively. To explore the linkage between HLA and COVID-19 severity, we applied fine-mapping analysis to dissect the HLA association with mild and severe cases. Using In-silico binding predictions to map the binding of risk/protective HLA to the viral structural proteins, we found the differential presentation of viral peptides in both ancestries. Lastly, extrapolation of the identified HLA from the cohort to the worldwide population revealed notable correlations. The study uncovers possible differences in susceptibility to COVID-19 in different ancestral origins in the genetic background, which may provide new insights into the pathogenesis and clinical treatment of the disease.
Computational rewiring of allosteric pathways reprograms GPCR selective responses to ligands
Authors: Keri D. , Hijazi M. , Oggier A. , Barth P. 
Published: April 2022

AbstractG-protein-coupled receptors (GPCRs) are the largest class of cell surface receptors and drug targets, and respond to a wide variety of chemical stimuli to activate diverse cellular functions. Understanding and predicting how ligand binding triggers a specific signaling response is critical for drug discovery and design but remains a major challenge. Here, computational design of GPCR allosteric functions is used to uncover the mechanistic relationships between agonist ligand chemistry, receptor sequence, structure, dynamics and allosteric signaling in the dopamine D2 receptor. Designed gain of function D2 variants for dopamine displayed very divergent G-protein signaling responses to other ligand agonists that strongly correlated with ligand structural similarity. Consistent with these observations, computational analysis revealed distinct topologies of allosteric signal transduction pathways for each ligand-bound D2 pair that were perturbed differently by the designs. We leveraged these findings by rewiring ligand-specific pathways and designed receptors with highly selective ligand responses. Overall, our study suggests that distinct ligand agonists can activate a given signaling effector through specific “allosteric activator” moieties that engage partially independent signal transmission networks in GPCRs. The results provide a mechanistic framework for understanding and predicting the impact of sequence polymorphism on receptor pharmacology, informing selective drug design and rationally designing receptors with highly selective ligand responses for basic and therapeutic applications.
Prediction of infectivity of SARS-CoV2: Mathematical model with analysis of docking simulation for spike proteins and angiotensin-converting enzyme 2
Authors: Takaoka Yutaka , Sugano Aki , Morinaga Yoshitomo , Ohta Mika , Miura Kenji , Kataguchi Haruyuki , Kumaoka Minoru , Kimura Shigemi , Maniwa Yoshimasa 
Published: April 2022

ABSTRACTVariants of a coronavirus (SARS-CoV-2) have been spreading in a global pandemic. Improved understanding of the infectivity of future new variants is important so that effective countermeasures against them can be quickly undertaken. In our research reported here, we aimed to predict the infectivity of SARS-CoV-2 by using a mathematical model with molecular simulation analysis, and we used phylogenetic analysis to determine the evolutionary distance of the spike protein gene (S gene) of SARS-CoV-2. We subjected the six variants and the wild type of spike protein and human angiotensin-converting enzyme 2 (ACE2) to molecular docking simulation analyses to understand the binding affinity of spike protein and ACE2. We then utilized regression analysis of the correlation coefficient of the mathematical model and the infectivity of SARS-CoV-2 to predict infectivity. The evolutionary distance of the S gene correlated with the infectivity of SARS-CoV-2 variants. The coefficient of the mathematical model obtained with results of molecular docking simulation also correlated with the infectivity of SARS-CoV-2 variants. These results suggest that the data from the docking simulation for the receptor binding domain of variant spike proteins and human ACE2 were valuable for prediction of SARS-CoV-2 infectivity. In addition, we developed a mathematical model for prediction of SARS-CoV-2 variant infectivity by using binding affinity obtained via molecular docking and the evolutionary distance of the S gene.
In vitro reconstitution of calcium-dependent recruitment of the human ESCRT machinery in lysosomal membrane repair
Authors: Shukla Sankalp , Larsen Kevin P. , Ou Chenxi , Rose Kevin , Hurley James H. 
Published: March 2022

AbstractThe endosomal sorting complex required for transport (ESCRT) machinery has been shown to be centrally involved in repair of damage to both the plasma and lysosome membranes. ESCRT recruitment to sites of damage occurs on a fast time scale, and Ca2+ has been proposed to play a key signaling role in the process. Here, we show that the Ca2+-binding regulatory protein ALG-2 binds directly to negatively charged membranes in a Ca2+-dependent manner. Next, by monitoring the colocalization of ALIX with ALG-2 on negatively charged membranes, we show that ALG-2 recruits ALIX to the membrane. Furthermore, we show that ALIX recruitment to membrane orchestrates the downstream assembly of late-acting CHMP4B, CHMP3, CHMP2A subunits along with the AAA+ ATPase VPS4B. Finally, we show that ALG-2 can also recruit the ESCRT-III machinery to the membrane via the canonical ESCRT-I/II pathway. Our reconstitution experiments delineate the minimal sets of components needed to assemble the entire membrane repair machinery and open a new avenue for mechanistic understanding of endolysosomal membrane repair.Significance statementOne of the ways by which protein aggregates can propagate and lead to progression of a neurodegenerative disease is by damaging the membrane that is destined to degrade the misfolded, aggregated protein. ESCRT machinery has been implicated in sealing these damaged membranes, and the nature of the membrane recruitment trigger signal for this machinery is a major open question. Here, we show in vitro that ALG-2 can bring ESCRT machinery to membranes in a Ca2+-dependent manner.
Multi-environment genome-wide association mapping of culm morphology traits in barley
Authors: Bretani G. , Shaaf S. , Tondelli A. , Cattivelli L. , Delbono S. , Waugh R. , Thomas W. , Russell J. , Bull H. , Igartua E. , Casas A. , Gracia P. , Rossi R. , Schulman A. , Rossini L. 
Published: April 2022

AbstractIn cereals with hollow internodes, lodging resistance is influenced by morphological characteristics such as internode diameter and culm wall thickness. Despite their relevance, knowledge of the genetic control of these traits and their relationship with lodging is lacking in temperate cereals such as barley. To fill this gap, we developed an image-analysis based protocol to accurately phenotype culm diameter and culm wall thickness across 261 barley accessions. Analysis of culm trait data collected from field trials in 7 different environments revealed genetic control as supported by high heritability values, as well as genotype-by-environment interactions. The collection was structured mainly according to row-type, which had a confounding effect on culm traits as evidenced by phenotypic correlations. In addition, culm traits showed strong negative correlations with lodging but weak correlations with plant height across row-types, indicating the possibility of improving lodging resistance independent of plant height. Using 50k iSelect SNP genotyping data, we conducted multi-environment genome-wide association studies using mixed model approach across the whole panel and row-type subsets: we identified a total of 192 QTLs for the studied traits, including subpopulation-specific QTLs and several main effect loci for culm traits showing negative effects on lodging without impacting plant height. Providing first insights into the genetic architecture of culm morphology in barley and the possible role of candidate genes involved in hormone and cell wall related pathways, this work supports the potential of loci underpinning culm features to improve lodging resistance and increase barley yield stability under changing environments.One-sentence summaryGenetic analysis of a diverse collection of European barleys reveals genomic regions underpinning stem morphological features associated with lodging resistance.
Selective IL13Rα2-Targeted Functionality of IL13-Ligand CARs is Enhanced by Inclusion of 4-1BB Co-Stimulation
Authors: Starr Renate , Yang Xin , Aguilar Brenda , Gumber Diana , Huard Stephanie , Wang Dongrui , Chang Wen-Chung , Brito Alfonso , Chiu Vivian , Ostberg Julie R. , Badie Benham , Forman Stephen J. , Alizadeh Darya , Wang Leo D. , Brown Christine E. 
Published: March 2022

ABSTRACTChimeric antigen receptor (CAR) T cell immunotherapy is emerging as a powerful strategy for cancer therapy; however, an important safety consideration is the potential for off-tumor recognition of normal tissue. This is particularly important as ligand-based CARs are optimized for clinical translation. Our group has developed and clinically translated an IL13(E12Y) ligand- based CAR targeting the cancer antigen IL13Rα2 for treatment of glioblastoma (GBM). There remains limited understanding of how IL13-ligand CAR design impacts the activity and selectivity for the intended tumor-associated target IL13Rα2 versus the more ubiquitous unintended target IL13Rα1. In this study, we functionally compared IL13(E12Y)-CARs incorporating different intracellular signaling domains, including first-generation CD3ζ- containing CARs (IL13ζ), second-generation 4-1BB- (CD137) or CD28-containing CARs (IL13- BBζ or IL13-28ζ), and third-generation CARs containing both 4-1BB and CD28 (IL13-28BBζ). In vitro co-culture assays at high tumor burden establish that 2nd generation IL13-BBζ or IL13- 28ζ outperform first-generation IL13ζ and 3rd generation IL13-28BBζ CAR designs, with IL13- BBζ providing superior CAR proliferation and in vivo anti-tumor potency in human xenograft mouse models. IL13-28ζ displayed a lower threshold for antigen recognition, resulting in higher off-target IL13Rα1 reactivity both in vitro and in vivo. Syngeneic mouse models of GBM also demonstrate safety and anti-tumor potency of murine IL13-BBζ CAR T cells delivered systemically after lymphodepletion. These findings support the use of IL13-BBζ CARs for greater selective recognition of IL13Rα2 over IL13Rα1, higher proliferative potential, and superior anti-tumor responsiveness. This study exemplifies the potential of modulating factors outside the antigen targeting domain of a CAR to improve selective tumor recognition..
An open protocol for modeling T Cell Clonotype repertoires using TCRβ CDR3 sequences
Authors: Gurun Burcu , Horton Wesley , Murugan Dhaarini , Zhu Biqing , Leyshock Patrick , Kumar Sushil , Byrne Katelyn T. , Vonderheide Robert H. , Margolin Adam A. , Mori Motomi , Spellman Paul T. , Coussens Lisa M. , Speed Terence P. 
Published: April 2022

ABSTRACTT cell receptor (TCR) repertoires can be profiled using next generation sequencing (NGS) to monitor dynamical changes in response to disease and other perturbations. Several strategies for profiling TCRs have been recently developed with different benefits and drawbacks. Genomic DNA-based bulk sequencing, however, remains the most cost-effective method to profile TCRs. The major disadvantage of this method is the need for multiplex target amplification with a large set of primer pairs with potentially very different amplification efficiencies. One approach addressing this problem is by iteratively adjusting the concentrations of the primers based on their efficiencies, and then computationally correcting any remaining bias. Yet there are no standard, publicly available protocols to process and analyze raw sequencing data generated by this method. Here, we utilize an equimolar primer mixture and propose a single statistical normalization step that efficiently corrects for amplification bias post sequencing. Using samples analyzed by both approaches, we show that the concordance between bulk clonality metrics obtained from using the commercial kits and that developed herein is high. Therefore, we suggest the method presented here as an inexpensive and non-commercial alternative for measuring and monitoring adaptive dynamics in TCR clonotype repertoire.
Endothelial Caspase-9 Promotes Glial Changes, Inflammation, and Contrast Sensitivity Decline in Retinal Vascular Injury
Authors: Ortiz Crystal Colón , Neal Albertine M. , Avrutsky Maria I. , Choi Monica , Smart Jade , Lawson Jacqueline , Troy Carol M. 
Published: March 2022

ABSTRACTRetinal glial cells— microglia, astrocytes, and Müller glia—provide homeostatic support, regulate vascular blood flow, and react to injury by releasing inflammatory cytokines. Glial reactivity has been shown to be relevant for retinal vascular pathology and neuronal death. Non-apoptotic expression of endothelial caspase-9 (EC Casp9) was recently identified as a key mediator of retinal edema, hypoxic-ischemic injury, and neurodegeneration in retinal vein occlusion (RVO). In the current study we aimed to determine the glial responses that are modulated by EC Casp9 as a means to identify relevant neuro-immune mechanisms for the development of retinal edema and neurodegeneration. To this end we used a mouse model of RVO and a tamoxifen inducible EC Casp9 KO mouse line. We show that EC Casp9 leads to an increase in reactive microglia and to macrogliosis in a time-dependent manner. RVO induced an EC Casp9 dependent astroglial caspase-6 and cleavage of GFAP. Cytokine array analysis revealed that RVO increases expression of inflammatory cytokines out of which CX3CL1, IGF-1, IL-4, LIX, IL-1α, M-CSF, TNF-α, IL-1β, IL-10, and VEGF-A, were regulated by EC Casp9. Moreover, we found that EC Casp9 deletion resulted in protection from contrast sensitivity decline one day post-RVO. These results demonstrate that caspase-9 in hypoxic endothelial cells regulates retinal inflammatory signaling in microglia, astrocytes and Müller cells and changes in visual function.
OTTERS: A powerful TWAS framework leveraging summary-level reference data
Authors: Dai Qile , Zhou Geyu , Zhao Hongyu , Võsa Urmo , Franke Lude , Battle Alexis , Teumer Alexander , Lehtimäki Terho , Raitakari Olli , Esko Tõnu ,   eQTLGen Consortium, Epstein Michael P. , Yang Jingjing 
Published: April 2022

AbstractMost existing TWAS tools require individual-level eQTL reference data and thus are not applicable to summary-level reference eQTL datasets. The development of TWAS methods that can harness summary-level reference data is valuable to enable TWAS in broader settings and enhance power due to increased reference sample size. Thus, we develop a TWAS framework called OTTERS (Omnibus Transcriptome Test using Expression Reference Summary data) that adapts multiple polygenic risk score (PRS) methods to estimate eQTL weights from summary-level eQTL reference data and conducts an omnibus TWAS. We show that OTTERS is a practical and powerful TWAS tool by both simulations and application studies.
HTL/KAI2 signalling substitutes for light to control plant germination
Authors: Bunsick Michael , Xu Zhenhua , Pescetto Gianni , Ly George , Hountalas Jenna , Boyer François-Didier , McErlean Christopher S. P. , Scholes Julie D. , Lumba Shelley 
Published: March 2022

SUMMARYDeciphering signalling pathways is essential to understanding how organisms respond to environmental cues but elucidating how these signalling pathways evolve in new environments is less clear.1,2 Most plants, for example, monitor multiple environmental cues to optimize the time and place to germinate. Some root parasitic plants, however, germinate in response to small molecules like strigolactones (SLs) emanating from host roots3,4 whilst a number of ephemeral weeds germinate in response to chemicals called karrikins (KARs) released after a forest fire.5,6 Although these species represent distinct clades, they use the same HYPOSENSITIVE TO LIGHT/KARRIKIN INSENSITIVE 2 (HTL/KAI2) signalling pathway to perceive strigolactones or karrikins, which suggests convergent evolution.3,5 Because specialist lifestyles are derived traits, it is not clear if HTL/KAI2 signalling in these species evolved from a specific germination-signalling pathway or whether this pathway had other functions that were co-opted for specialist germination circumstances. Here, we show HTL/KAI2 signalling in Arabidopsis bypasses the light requirement for germination. In part, this is because the HTL/KAI2 downstream component, SMAX1 impinges on PHYTOCHROME INTERACTING FACTOR 1/PHYTOCHROME INTERACTING FACTOR 3-LIKE 5 (PIF1/PIL5)-regulated hormone response pathways conducive to germination. We identified Arabidopsis accessions that can germinate in the dark, which had altered expression of HTL/KAI2 signalling components, suggesting that divergence in this signalling pathway occurs in nature. Moreover, Arabidopsis HTL/KAI2-regulated gene signatures were observed in germinating Striga seed. The ability of HTL/KAI2 signalling to substitute for light advances an explanation for how some specialist plants evolved their underground germination behaviour in response to specific environments.
Glucocorticoids Mediate Transcriptome-wide Alternative Polyadenylation: Mechanisms and Functional Implications
Authors: Le Nguyen Thanh Thanh , Liu Duan , Gao Huanyao , Ye Zhenqing , Lee Jeong-Heon , Wei Lixuan , Yu Jia , Zhang Lingxin , Wang Liewei , Ordog Tamas , Weinshilboum Richard M. 
Published: March 2022

ABSTRACTAlternative polyadenylation (APA) is a common genetic regulatory mechanism that generates distinct 3′ ends for RNA transcripts. Changes in APA have been associated with multiple biological processes and disease phenotypes. However, the role of hormones and their drug analogs in APA remains largely unknown. In this study, we investigated transcriptome-wide the impact of glucocorticoids on APA in 30 human B-lymphoblastoid cell lines. We found that glucocorticoids could regulate APA of a subset of genes, possibly by changing the expression of 142 RNA-binding proteins, some with known APA-regulating properties. Interestingly, genes with glucocorticoid-mediated APA were enriched in viral translation-related pathways, while genes with glucocorticoid-mediated expression were enriched in interferon and interleukin pathways, suggesting that glucocorticoid-mediated APA might result in functional consequences distinct from gene expression. Glucocorticoid-mediated APA was also cell-type-specific, suggesting an action of glucocorticoids that may be unique to immune regulation. We also observed evidence for genotype-dependent glucocorticoid-mediated APA, providing potential functional mechanisms for a series of common genetic variants that had previously been associated with immune disorders, but without a clear mechanism. In summary, this study reports a series of novel observations regarding the impact of glucocorticoids on APA, suggesting novel avenues for mechanistic studies of hormonal biology.
A fluctuation-based approach to infer kinetics and topology of cell-state switching
Authors: Saint-Antoine Michael , Grima Ramon , Singh Abhyudai 
Published: April 2022

AbstractIn the noisy cellular environment, RNAs and proteins are subject to considerable stochastic fluctuations in copy numbers over time. As a consequence, single cells within the same isoclonal population can differ in their expression profile and reside in different phenotypic states. The dynamic nature of this intercellular variation, where individual cells can transition between different states over time makes it a particularly hard phenomenon to characterize. Here we propose a novel fluctuation-test approach to infer the kinetics of transitions between cell states. More specifically, single cells are randomly drawn from the population and grown into cell colonies. After growth for a fixed number of generations, the number of cells residing in different states is assayed for each colony. In a simple system with reversible switching between two cell states, our analysis shows that the extent of colony-to-colony fluctuations in the fraction of cells in a given state is monotonically related to the switching kinetics. Several closed-form formulas for inferring the switching rates from experimentally quantified fluctuations are presented. We further extend this approach to multiple cell states where harnessing fluctuation signatures can reveal both the topology and the rates of cell-state switching. In summary, our analysis provides a powerful approach for dissecting cell-state transitions based on asingletime point measurement. This is especially important for scenarios where a measurement involves killing the cell (for example, performing single-cell RNA-seq or assaying whether a microbial/cancer cell is in a drug-sensitive or drug-tolerant state), and hence the state of the same cell cannot be measured at different time points.