bluuebunny/crossref_metadata_2025_split huggingface dataset:
Structural and functional analyses of viral H2 protein of the vaccinia virus entry fusion complex
Authors: Kao Chi-Fei , Liu Chang-Yi , Hsieh Chia-Lin , Carillo Kathleen Joyce D. , Tzou Der-Lii M. , Wang Hao-Ching , Chang Wen 
Published: August 2023

AbstractVirus-mediated membrane fusion involves conformational changes of the viral fusion protein to fuse the opposing viral and host lipid bilayers. Unlike all other known viruses that contain a single fusion protein, poxviruses harbor a multimeric protein complex of 11 subunits, termed the entry fusion complex (EFC), to mediate fusion with host membranes. Yet, how the poxviral EFC mediates membrane fusion remains enigmatic. To establish the mechanism of EFC-triggered membrane fusion, we are deciphering the structure and function of individual EFC components. Here, we determined the crystal structure of the H2 ectodomain by X-ray diffraction, revealing a folded conformation comprising a central five-stranded β-sheet and three cladding α-helices. We reconstructed the full-length H2 byin silicoprediction, revealing that the N-terminal region (aa 51-90) of H2 protein may fold as a long helix connecting the ectodomain and transmembrane region. Using alanine-mutagenesis screening in a transient complementation system, coimmunoprecipitation, isothermal titration calorimetry and MV-triggered membrane fusion assays, we concluded that the surface of the ectodomain of H2 protein, including two loop regions,170LGYSG174and125RRGTGDAW132, constitutes a broad A28-binding region. Moreover, although not involved in A28 binding, the N-terminal helical region approximal to the transmembrane part, encompassing64RIK66,72W, and83ESDRGR88, is also crucial for viral EFC formation and MV infectivity.
Widespread regulation of the maternal transcriptome by Nanos in Drosophila
Authors: Marhabaie Mohammad , Wharton Tammy H. , Kim Sung Yun , Wharton Robin P. 
Published: August 2023

AbstractThe translational repressor Nanos (Nos) regulates a single target, maternalhunchback(hb)mRNA, to govern abdominal segmentation in the early Drosophila embryo. Nos is recruited specifically to sites in the 3’-UTR ofhbmRNA in collaboration with the sequence-specific RNA-binding protein Pumilio (Pum); on its own, Nos has no binding specificity. Nos is expressed at other stages of development, but very few mRNA targets that might mediate its action at these stages have been described. Nor has it been clear whether Nos is targeted to other mRNAs in concert with Pum or via other mechanisms. In this report, we identify mRNAs targeted by Nos via two approaches. In the first method, we identify mRNAs depleted upon expression of a chimera bearing Nos fused to the nonsense mediated decay (NMD) factor Upf1. We find that, in addition tohb, Upf1-Nos depletes ∼2600 mRNAs from the maternal transcriptome in early embryos. Virtually all of these appear to be targeted in a canonical,hb-like manner in concert with Pum. In a second, more conventional approach, we identify mRNAs that are stabilized during the maternal zygotic transition (MZT) in embryos fromnos-females. Most (86%) of the 1185 mRNAs regulated by Nos are also targeted by Upf1-Nos, validating use of the chimera. Approximately 60% of mRNAs targeted by Upf1-Nos are not stabilized in the absence of Nos. However, Upf1-Nos mRNA targets are hypo-adenylated and inefficiently translated at the ovary-embryo transition, whether or not they suffer Nos-dependent degradation in the embryo. We suggest that the late ovarian burst of Nos represses a large fraction of the maternal transcriptome, priming it for later degradation by other factors during the MZT in the embryo.
An autochthonous model of lung cancer in the Naked Mole-Rat (Heterocephalus glaber)
Authors: Shepard Alyssa , Troutman Scott , Hoxha Sany , Lester Daniel , Khaled Walid , Smith Ewan St. John , Park Thomas , Buffenstein Rochelle , Du Dongliang , Teng Mingxiang , Crish Christine , Tsai Kenneth Y. , Flores Elsa R. , Ventura Andrea , Kissil Joseph L. 
Published: August 2023

AbstractStudies on cancer resistance in the naked mole-rat (NMR) have generally failed to interrogate possible resistance mechanisms in a physiological context. Here, we provide evidence that the NMR presents as a novel model of tumor initiation. We developed an endogenous lung cancer model in NMRs, driven by an oncogenic Eml4-Alk fusion protein introduced through CRISPR- mediated genome editing. While this is sufficient to drive tumorigenesis in mice, the development of progressive disease in NMRs required the additional loss of key tumor suppressors. Our results show that tumor initiation in NMRs more closely recapitulates that of human tumors. This suggests that the proposed “resistance” of NMRs to cancer development may stem from tumor initiation events that are likely to be comparable to the mechanisms in human cells.One-Sentence SummaryTumor development in the cancer-resistant naked mole-rat more accurately represents the tumor initiation process in humans.
Simian Immunodeficiency Virus and Storage Buffer: Field-friendly preservation methods for RNA viral detection in primate feces
Authors: Wilde Tessa H.C. , Shukla Rajni Kant , Madden Christopher , Vodovotz Yael , Sharma Amit , Mcgraw W. Scott , Hale Vanessa L. 
Published: August 2023

AbstractWild non-human primates carry many types of RNA viruses, including simian immunodeficiency virus (SIV), simian foamy virus, simian T-cell leukemia virus, and hepatitis C virus. These viruses can also infect humans via zoonotic transmission through handling and consumption of primate bushmeat. Characterizing viral prevalence and shedding in natural hosts is critical to understand infection and transmission risks within and between primate species. Here, we sought to identify a robust “field-friendly” method (i.e., without freezing or refrigeration) for preserving viral RNA, specifically SIV, in primate fecal samples. Fecal samples were collected from a mantled guereza colobus (Colobus guereza) housed at the Columbus Zoo and Aquarium. Samples were homogenized and inoculated with three concentrations (low, medium, high) of inactivated SIV virus and preserved in four different storage buffers (DNA/RNA Shield, RNAlater, 95% Ethanol, and Viral Transport Medium). SIV viral RNA was then extracted from samples at four time points (1 week, 4 weeks, 8 weeks, and 12 weeks) to determine the efficacy of each buffer for preserving SIV RNA. Quantitative RT-PCR was used for detection and quantification of viral RNA. At all concentrations, DNA/RNA Shield yielded the highest average SIV virion concentrations. We then successfully validated this approach using fecal samples from known SIV-positive and SIV-negative sooty mangabeys (Cercocebus atys) housed at Emory National Primate Research Center. Our results indicate that DNA/RNA shield is an optimal “field-friendly” buffer for preserving SIV RNA in fecal samples over time, and may also be effective for preserving other RNA viruses in feces.ImportanceHuman immunodeficiency virus (HIV) was introduced into human populations through zoonotic transmission of SIV from African primates, leading to a global epidemic and ongoing worldwide public health issue. SIV occurs naturally in over 40 primate species in sub-Saharan Africa and these viruses have crossed species barriers on multiple occasions, leading to the spread of HIV-1 and HIV-2. Quantifying RNA viruses in wild primate populations can be challenging as invasive sampling is often not feasible, and many field stations lack ready access to a freezer for storing biological samples. This study compares SIV RNA preservation and recovery across multiple storage buffers to identify a robust field-friendly option for RNA viral detection in noninvasively collected feces. Our results will inform future fieldwork and facilitate improved approaches to characterizing prevalence, shedding, and transmission of RNA viruses like SIV in natural hosts including wild-living nonhuman primates.
OpgH is an essential regulator ofCaulobactermorphology
Authors: Daitch Allison K. , Goley Erin D. 
Published: August 2023

AbstractBacterial growth and division rely on intricate regulation of morphogenetic complexes to remodel the cell envelope without compromising envelope integrity. Significant progress has been made in recent years towards understanding the regulation of cell wall metabolic enzymes. However, other cell envelope components play a role in morphogenesis as well. Components required to maintain osmotic homeostasis are among these understudied envelope-associated enzymes that may contribute to cell morphology. A primary factor required to protect envelope integrity in low osmolarity environments is OpgH, the synthase of osmoregulated periplasmic glucans (OPGs). Here, we demonstrate that OpgH is essential in the ⍺-proteobacteriumCaulobacter crescentus. Unexpectedly, depletion of OpgH results in striking asymmetric bulging and cell lysis, accompanied by misregulation of cell wall insertion and mislocalization of morphogenetic complexes. The enzymatic activity of OpgH is required for normal cell morphology as production of an OpgH mutant that disrupts a conserved glycosyltransferase motif phenocopies the depletion. Our data establish a surprising function for an OpgH homolog in morphogenesis and reveal an essential role of OpgH in maintaining proper cell morphology during normal growth and division inCaulobacter.SignificanceBacteria must synthesize and fortify the cell envelope in a tightly regulated manner to orchestrate growth and adaptation. Osmoregulated periplasmic glucans (OPGs) are important, but poorly understood, constituents of Gram-negative cell envelopes that contribute to envelope integrity and protect against osmotic stress. Here, we determined that the OPG synthase OpgH plays a surprising, essential role in morphogenesis inCaulobacter crescentus. Loss of OpgH causes asymmetric cell bulging and lysis via misregulation of the localization and activity of morphogenetic complexes. Because cell envelope integrity is critical for bacterial survival, understanding how OpgH activity contributes to morphogenesis could aid in the development of antibiotic therapies.
UPP affects chloroplast development by interfering with chloroplast proteostasis
Authors: Scherer Vanessa , Bellin Leo , Schwenkert Serena , Lehmann Martin , Rinne Jannis , Witte Claus-Peter , Jahnke Kathrin , Richter Andreas , Pruss Tobias , Lau Anne , Leister Dario , Möhlmann Torsten 
Published: August 2023

AbstractArabidopsis uracil phosphoribosyltransferase (UPP) has been identified as an essential protein with a previously unknown moonlighting activity. By analysis of UPP amiRNA mutants, we first confirmed a vital function of UPP in chloroplast development and growth which seems unrelated to nucleotide homeostasis since nucleotide levels were not altered in the mutants. Impaired photosynthesis and reductions in carbohydrate contents in these mutants resulted in an inability to induce flavonoid biosynthesis after high light (HL) treatment. Additionally, levels of raffinose, proline and fumarate, acting as osmoprotectants and carbon-stores were reduced as well. Proteomic analysis suggests a role of UPP in chloroplast proteostasis, particularly under HL, and this was confirmed by immunoblots. PetC, the iron-sulfur protein of the Cytb6f complex, was identified as putative UPP target that is massively reduced in UPP knock-down and knock-out plants, resulting in blocked photosynthetic electron transport, seen by increased unregulated energy dissipation and subsequent damage to the D1 protein of PSII. Proteases, including thylakoid-bound FtsHs, were up-regulated together with components of the chloroplast protein import machinery. We hypothesize that the UPP assists in the targeting of PetC and further interacting proteins to the thylakoid and when this mechanism is impaired in corresponding mutants chloroplast proteases are upregulated as a countermeasure.
Chemogenetic inhibition of IST1-CHMP1B interaction impairs endosomal recycling and promotes unconventional LC3 lipidation at stalled endosomes
Authors: Knyazeva Anastasia , Li Shuang , Corkery Dale P. , Shankar Kasturika , Herzog Laura K. , Zhang Xuepei , Singh Birendra , Niggemeyer Georg , Grill David , Gilthorpe Jonathan D. , Gaetani Massimiliano , Carlson Lars-Anders , Waldmann Herbert , Wu Yao-Wen 
Published: August 2023

AbstractThe Endosomal Sorting Complex Required for Transport (ESCRT) machinery constitutes a multisubunit protein complex that plays an essential role in membrane remodeling and trafficking. ESCRTs regulate a wide array of cellular processes, encompassing cytokinetic abscission, cargo sorting into multivesicular bodies (MVBs), membrane repair and autophagy. Given the versatile functionality of ESCRTs and the intricate organizational structure of the ESCRT complex, the targeted modulation of distinct ESCRT-mediated membrane deformations for functional dissection poses a considerable challenge. This study presents a pseudo-natural product targeting IST1-CHMP1B within the ESCRT-III complex. This compound specifically disrupts the interaction between IST1 and CHMP1B, thereby inhibiting the formation of IST1-CHMP1B copolymers essential for normal-topology membrane scission events. While the compound has no impact on cytokinesis, MVB sorting and exosome biogenesis, it rapidly hinders transferrin receptor (TfR) recycling in cells, resulting in the accumulation of transferrin in perinuclear endosomal recycling tubules. Stalled recycling endosomes acquire unconventional LC3 lipidation, establishing a link between non-canonical LC3 lipidation and endosomal recycling.
The protective function of an immunity protein against thecis-toxic effects of aXanthomonasType IV Secretion System Effector
Authors: Oka Gabriel U. , Souza Diorge P. , Sgro Germán G. , Guzzo Cristiane R. , Dunger German , Farah Chuck S. 
Published: August 2023

AbstractMany bacterial species use specialized secretion systems to translocate proteinaceous toxic effectors into target bacterial cells. In most cases, effectors are encoded in bicistronic operons with their cognate immunity proteins. The current model is that immunity proteins could, in principle, provide protection in two different ways: i) by avoiding self-intoxication (suicide orcis-intoxication) or ii) by inhibiting intoxication due to “friendly-fire” translocation from neighboring sister cells (fratricide ortrans-intoxication). Here, we set out to distinguish between these two protection mechanisms in the case of the bactericidalXanthomonas citriType IV Secretion System (X-T4SS), where killing is due to the action of a cocktail of secreted effectors (X-Tfes) that are inhibited by their cognate immunity proteins (X-Tfis). We use a set ofX. citrimutants lacking multiple X-Tfe/X-Tfi pairs to show that X-Tfis are not absolutely required to protect againsttrans-intoxication. Our investigation then focused on thein vivofunction of the lysozyme-like effector X-TfeXAC2609and its cognate immunity protein X-TfiXAC2610. We observe the accumulation of damage in theX. citricell envelope and inhibition of biofilm formation due to the action of X-TfeXAC2609in the absence of X-TfiXAC2610. We show that X-TfeXAC2609toxicity is independent of an active X-T4SS and that X-TfiXAC2610protects the cell colony against X-TfeXAC2609-inducedcis-intoxication via autolysis.In vitroassays employing X-TfiXAC2610mutants were used to test and validate an AlphaFold2-derived model of the X-TfeXAC2609-X-TfiXAC2610complex which presents topological similarities with the distantly related Tse1/Tsi1 complex fromP. aeruginosaand the the i-type lysozyme fromMeretrix lusoria(MI-iLys) in complex with PliI-Ah fromAeromonas hydrophila. While immunity proteins in other systems have been shown to protect against attacks by sister cells (trans-intoxication), this is the first description of an antibacterial secretion system in which the immunity proteins are dedicated to protecting cells againstcis-intoxication.
Microbe transmission from pet shop to lab-reared zebrafish reveals a pathogenic birnavirus
Authors: Rice Marlen C. , Elde Nels C. , Gagnon James A. , Balla Keir M. 
Published: August 2023

ABSTRACTZebrafish are popular research organisms selected for laboratory use due in part to widespread availability from the pet trade. Many contemporary colonies of laboratory zebrafish are maintained in aquaculture facilities that monitor and aim to curb infections that can negatively affect colony health and confound experiments. The impact of laboratory control on the microbial constituents associated with zebrafish in research environments compared to the pet trade are unclear. Diseases of unknown causes are common in both environments. We conducted a metagenomic survey to broadly compare the zebrafish-associated microbes in pet trade and laboratory environments. We detected many microbes in animals from the pet trade that were not found in laboratory animals. Co-housing experiments revealed several transmissible microbes including a newly described non-enveloped, double-stranded RNA virus in the Birnaviridae family we name Rocky Mountain birnavirus (RMBV). Infections were detected in asymptomatic animals from the pet trade, but when transmitted to laboratory animals RMBV was associated with pronounced antiviral responses and hemorrhagic disease. These experiments highlight the pet trade as a distinct source of diverse microbes that associate with zebrafish and establish a paradigm for the discovery of newly described pathogenic viruses and other infectious microbes that can be developed for study in the laboratory.
Spatial patterning regulates neuron numbers in theDrosophilavisual system
Authors: Malin Jennifer A. , Chen Yen-Chung , Simon Félix , Keefer Evelyn , Desplan Claude 
Published: August 2023

SummaryNeurons must be made in the correct proportions to communicate with the appropriate synaptic partners and form functional circuits. In theDrosophilavisual system, multiple subtypes of Distal medulla (Dm) inhibitory interneurons are made in distinct, reproducible numbers—from 5 to 800 per optic lobe. These neurons are born from a crescent-shaped neuroepithelium called the Outer Proliferation Center (OPC), which can be subdivided into specific domains based on transcription factor expression. We fate mapped Dm neurons and found that more abundant neural types are born from larger neuroepithelial subdomains, while less abundant subtypes are born from smaller ones. Additionally, morphogenetic Dpp/BMP signaling provides a second layer of patterning that subdivides the neuroepithelium into smaller domains to provide more granular control of cell proportions. Apoptosis appears to play a minor role in regulating Dm neuron abundance. This work describes an underappreciated mechanism for the regulation of neuronal stoichiometry.
Application of fluorescence lifetimes to multi-imaging analysis in plant cells
Authors: Aoyama Tsuyoshi , Sugimoto Nagisa , Sato Yoshikatsu 
Published: August 2023

AbstractMulti-imaging analysis has become an indispensable technique to visualize multiple target proteins and intracellular components simultaneously. While current multi-imaging analysis relies on the differences in emission spectra of fluorescent molecules, the use of fluorescence lifetime imaging microscopy (FLIM), which exploits the differences in fluorescence lifetimes of fluorescent proteins, in multi-imaging analysis is quite limited. In this study, we successfully discriminated fluorescent proteins with similar colors but different fluorescence lifetimesin vitroandin planta. We found that four fluorescent proteins with similar emission spectra could be distinguished by FLIM. In addition, we found that FLIM could clearly separate fluorescent proteins if they differ by at least 0.2 ns. In a proof-of-concept experiments for plant live imaging, we transiently expressed fluorescent proteins with different subcellular localization tags inPhyscomitrium patensby particle bombardment. Each fluorescent protein exhibited its fluorescence lifetime at the subcellular localization corresponding to the localization tag inP. patenswith little or no effect of chlorophyll autofluorescence. Our results demonstrate the effectiveness of FLIM in revealing the spatiotemporal dynamics of a large number of fluorescent proteins in living plant cells.
Supply chain finance, firm performance and industry competition: empirical evidence from Pakistan
Authors: Sajid Memoona , Safdar Raheel 
Published: August 2023

PurposeThis study empirically tests the relationship between supply chain finance (SCF) and firm performance. Moreover, this study also investigates the potential role of industry competition in the proposed relationship between SCF and firm performance.Design/methodology/approachA conceptual framework is developed and tested using secondary data collected from 122 non-financial listed firms on the Pakistan Stock Exchange (PSX) for the period of ten years (2012–2021). Ordinary least squares (OLS) regression analysis is performed in STATA to validate the proposed relationships.FindingsThe results highlight that SCF has a positive impact on firm performance. Moreover, industry competition positively moderates the relationship between SCF and firm performance.Practical implicationsThis study would help firms in assessing the value of operational financing to their financially constrained suppliers/customers by adopting supply chain finance practices. Furthermore, this study will help understand the role of the competitive environment in supply chain finance decision-making.Originality/valueThe findings will help core firms better understand how implementing SCF benefits firm performance under high product competition, especially in emerging markets.
Adoption of blockchain technology in hospitality and tourism industry and sustainability performance: impact of technological turbulence and senior leadership support
Authors: Chaudhuri Ranjan , Chatterjee Sheshadri , Vrontis Demetris 
Published: August 2023

PurposeThe rapid increase of use of online platforms by the customers in the hospitality and tourism industry has invited the needs for using digital platforms by the concerned industry. In such a scenario, the purpose of this study is to examine how adoption of blockchain technology in hospitality and tourism industry could impact the sustainability performance of the organizations under the moderating influence of technological turbulence and senior leadership support.Design/methodology/approachWith the help of existing literature, stakeholder theory and dynamic capability view (DCV), a theoretical model is proposed. It was validated using the PLS-SEM technique with 311 respondents who have different managerial positions in the hospitality and tourism industry. The proposed theoretical model is unique and effective as it has high explanatory power.FindingsThe study demonstrates the importance of adopting BCT in the hospitality and tourism sector and how it could improve the sustainability performance of organizations in that sector. This study also finds that there is a significant moderating impact of technological turbulence and senior leadership support on such organizations that adopt BCT.Research limitations/implicationsThis study provides valuable inputs to practitioners in the industry by showing how adopting BCT can improve their sustainability performance. The study also demonstrates that leaders and the managers should support adopting BCT in their organizations and they can help to overcome any technological challenges that might come up while adopting it.Originality/valueThe present study proposes a unique theoretical model which was also validated using a statistical approach. Moreover, both stakeholder theory and dynamic capability view were integrated to propose the theoretical model, which is a novel attempt so far as adoption of BCT in hospitality and tourism industry is concerned.