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Found 37684 matches. Displaying 371-380
Barbelanne M, Lu Y, Kumar K, Zhang XX, Li CM, Park K, Warner A, Xu XZS, Shaha...
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C. elegans PPEF-type phosphatase (Retinal degeneration C ortholog) fun...

SCIENTIFIC REPORTS 2024 NOV 16; 14(1):? Article 28347
Primary (non-motile) cilia represent structurally and functionally diverse organelles whose roles as specialized cellular antenna are central to animal cell signaling pathways, sensory physiology and development. An ever-growing number of ciliary proteins, including those found in vertebrate photoreceptors, have been uncovered and linked to human disorders termed ciliopathies. Here, we demonstrate that an evolutionarily-conserved PPEF-family serine-threonine phosphatase, not functionally linked to cilia in any organism but associated with rhabdomeric (non-ciliary) photoreceptor degeneration in the Drosophila rdgC (retinal degeneration C) mutant, is a bona fide ciliary protein in C. elegans. The nematode protein, PEF-1, depends on transition zone proteins, which make up a 'ciliary gate' in the proximal-most region of the cilium, for its compartmentalization within cilia. Animals lacking PEF-1 protein function display structural defects to several types of cilia, including potential degeneration of microtubules. They also exhibit anomalies to cilium-dependent behaviors, including impaired responses to chemical, temperature, light, and noxious CO2 stimuli. Lastly, we demonstrate that PEF-1 function depends on conserved myristoylation and palmitoylation signals. Collectively, our findings broaden the role of PPEF proteins to include cilia, and suggest that the poorly-characterized mammalian PPEF1 and PPEF2 orthologs may also have ciliary functions and thus represent ciliopathy candidates.
Wang Y, Zheng P, Cheng YC, Wang ZK, Aravkin A
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WENDY: Covariance dynamics based gene regulatory network inference

MATHEMATICAL BIOSCIENCES 2024 NOV; 377(?):? Article 109284
Determining gene regulatory network (GRN) structure is a central problem in biology, with a variety of inference methods available for different types of data. Fora widely prevalent and challenging use case, namely single-cell gene expression data measured after intervention at multiple time points with unknown joint distributions, there is only one known specifically developed method, which does not fully utilize the rich information contained in this data type. We develop an inference method for the GRN in this case, netWork infErence by covariaNce DYnamics, dubbed WENDY. The core idea of WENDY is to model the dynamics of the covariance matrix, and solve this dynamics as an optimization problem to determine the regulatory relationships. To evaluate its effectiveness, we compare WENDY with other inference methods using synthetic data and experimental data. Our results demonstrate that WENDY performs well across different data sets.
Short B
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A new stress test for ryanodine receptors

JOURNAL OF GENERAL PHYSIOLOGY 2024 NOV 19; 156(12):? Article e202413716
JGP study (Steinz et al. https://doi.org/10.1085/jgp.202313515) reveals that oxidative stress can induce stable posttranslational modifications of RyR1 that increase the channel's open probability and could therefore disrupt muscle contractility.
Lercher A, Cheong JG, Bale MJ, Jiang CY, Hoffmann HH, Ashbrook AW, Lewy T, Yi...
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Antiviral innate immune memory in alveolar macrophages following SARS-CoV-2 i...

IMMUNITY 2024 NOV 12; 57(11):?
Pathogen encounter can result in epigenetic remodeling that shapes disease caused by heterologous pathogens. Here, we examined innate immune memory in the context of commonly circulating respiratory viruses. Single-cell analyses of airway-resident immune cells in a disease-relevant murine model of SARS-CoV-2 recovery revealed epigenetic reprogramming in alveolar macrophages following infection. Post-COVID-19 human monocytes exhibited similar epigenetic signatures. In airway-resident macrophages, past SARS-CoV-2 infection increased activity of type I interferon (IFN-I)-related transcription factors and epigenetic poising of antiviral genes. Viral pattern recognition and canonical IFN-I signaling were required for the establishment of this innate immune memory and augmented secondary antiviral responses. Antiviral innate immune memory mounted by airway-resident macrophages post-SARS-CoV-2 was necessary and sufficient to ameliorate secondary disease caused by influenza A virus and curtailed hyperinflammatory dysregulation and mortality. Our findings provide insights into antiviral innate immune memory in the airway that may facilitate the development of broadly effective therapeutic strategies.
Catanese J, Murakami TC, Catto A, Kenny PJ, Ibañez-Tallon I
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Precise 3D Localization of Intracerebral Implants Using a Simple Brain Cleari...

JOURNAL OF INTEGRATIVE NEUROSCIENCE 2024 NOV 20; 23(11):? Article 207
Background: Precise localization of intracerebral implants in rodent brains is required for physiological and behavioral studies, particularly if targeting deep brain nuclei. Traditional histological methods, based on manual estimation through sectioning can introduce errors and complicate data interpretation.Methods: Here, we introduce an alternative method based on recent advances in tissue-clearing techniques and light-sheet fluorescence microscopy. This method uses a simplified recipe of the Clear, Unobstructed Brain/Body Imaging Cocktails and Computational Analysis (CUBIC) method, which is a rapid clearing procedure using an aqueous-based solution compatible with fluorescence and fluorescence markers. We demonstrate the utility of this approach in anesthetized transgenic mice expressing channelrhodopsin-2 (ChR2) and enhanced yellow fluorescent fusion (EYFP) protein under the choline acetyltransferase (ChAT) promoter/enhancer regions (ChAT-ChR2-EYFP mice) with implanted linear silicon optrode probes into the midbrain interpeduncular nucleus (IPN).Results: By applying the red fluorescent DiD' dye (DiIC18(5) solid (1,1 '-Dioctadecyl-3,3,3 ',3 '-Tetramethylindodicarbocyanine, 4-Chlorobenzenesulfonate Salt) to the electrode surface, we precisely visualize the electrode localization in the IPN of ChAT-ChR2-EYFP mice. Three-dimensional brain videos from different orientations highlight the potential of this method. Optogenetic responses recorded from electrodes placed in the IPN validate these findings.Conclusions: This method allows for precise localization of brain implantation sites in transgenic mice expressing cell-specific fluorescence markers. It enables virtual brain slicing in any orientation, making it a useful tool for functional studies in mice.
Tse AL, Acreman CM, Ricardo-Lax I, Berrigan J, Lasso G, Balogun T, Kearns FL,...
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Distinct pathways for evolution of enhanced receptor binding and cell entry i...

PLOS PATHOGENS 2024 NOV; 20(11):? Article e1012704
Understanding the zoonotic risks posed by bat coronaviruses (CoVs) is critical for pandemic preparedness. Herein, we generated recombinant vesicular stomatitis viruses (rVSVs) bearing spikes from divergent bat CoVs to investigate their cell entry mechanisms. Unexpectedly, the successful recovery of rVSVs bearing the spike from SHC014-CoV, a SARS-like bat CoV, was associated with the acquisition of a novel substitution in the S2 fusion peptide-proximal region (FPPR). This substitution enhanced viral entry in both VSV and coronavirus contexts by increasing the availability of the spike receptor-binding domain to recognize its cellular receptor, ACE2. A second substitution in the S1 N-terminal domain, uncovered through the rescue and serial passage of a virus bearing the FPPR substitution, further enhanced spike:ACE2 interaction and viral entry. Our findings identify genetic pathways for adaptation by bat CoVs during spillover and host-to-host transmission, fitness trade-offs inherent to these pathways, and potential Achilles' heels that could be targeted with countermeasures.
Hayrapetyan A, Tumasyan A, Adam W, Andrejkovic JW, Bergauer T, Chatterjee S, ...
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Search for Soft Unclustered Energy Patterns in Proton-Proton Collisions at 13...

PHYSICAL REVIEW LETTERS 2024 NOV 5; 133(19):? Article 191902
The first search for soft unclustered energy patterns (SUEPs) is performed using an integrated luminosity of 138 fb(-1) of proton-proton collision data at root s = 13 TeV, collected in 2016-2018 by the CMS detector at the LHC. Such SUEPs are predicted by hidden valley models with a new, confining force with a large't Hooft coupling. In events with boosted topologies, selected by high-threshold hadronic triggers, the multiplicity and sphericity of clustered tracks are used to reject the background from standard model quantum chromodynamics. With no observed excess of events over the standard model expectation, limits are set on the cross section for production via gluon fusion of a scalar mediator with SUEP-like decays.
Fiedorczuk K, Iordanov I, Mihályi C, Szollosi A, Csanády L, Chen J
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The structures of protein kinase A in complex with CFTR : Mechanisms of phosp...

PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 2024 NOV 12; 121(46):? Article e2409049121
Protein kinase A (PKA) is a key regulator of cellular functions by selectively phosphorylating numerous substrates, including ion channels, enzymes, and transcription factors. It has long served as a model system for understanding the eukaryotic kinases. Using cryoelectron microscopy, we present complex structures of the PKA catalytic subunit (PKA-C) bound to a full- length protein substrate, the cystic fibrosis transmembrane conductance regulator (CFTR)-an ion channel vital to human health. CFTR gating requires phosphorylation of its regulatory (R) domain. Unphosphorylated CFTR engages PKA-C at two locations, establishing two "catalytic stations" near to, but not directly involving, the R domain. This configuration, coupled with the conformational flexibility of the R domain, permits transient interactions of the eleven spatially separated phosphorylation sites. Furthermore, we determined two structures of the open- pore CFTR stabilized by PKA-C, providing a molecular basis to understand how PKA-C stimulates CFTR currents even in the absence of phosphorylation.
Gonzalez CR, Basílio-Queirós D, Neehus AL, Merkert S, Tschritter D, Ünal S, H...
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Human CFTR deficient iPSC-macrophages reveal impaired functional and transcri...

FRONTIERS IN IMMUNOLOGY 2024 NOV 13; 15(?):? Article 1397886
Introduction Cystic fibrosis (CF) is a hereditary autosomal recessive disease driven by deleterious variants of the CFTR gene, leading, among other symptoms, to increased lung infection susceptibility. Mucus accumulation in the CF lung is, as of yet, considered as one important factor contributing to its colonization by opportunistic pathogens such as Pseudomonas aeruginosa. However, in recent years evidence was provided that alveolar macrophages, which form the first line of defense against airborne pathogens, seem to be intrinsically defective with regard to bactericidal functionality in the CF lung. To assess the impact of CFTR deficiency in human macrophages only insufficient systems are available.Methods To address this problem and to evaluate the role of CFTR in human macrophages, we successfully differentiated human induced pluripotent stem cells (iPSC) from a CF p.Phe508del homozygous individual and a healthy donor into primitive macrophages (iMac Delta F508 and iMacWT), respectively, and compared the bactericidal functionality in the relevant cell type.Results iMac Delta F508 showed impaired P. aeruginosa clearance and intracellular killing capacity in comparison to iMacWT. Furthermore, iMac Delta F508 exhibited a less acidic lysosomal pH, and upon P. aeruginosa infection, there were signs of mitochondrial fragmentation and autophagosome formation together with a hyperinflammatory phenotype and deficient type I interferon response.Conclusion In summary, we present a defective phenotype in iMac Delta F508 upon P. aeruginosa infection, which will constitute an ideal platform to further study the role of macrophages in the context of CF.
Sarfo FS, Frickmann H, Dompreh A, Osei Asibey S, Boateng R, Weinreich F, Osei...
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High Clinical Burden of Cryptosporidium spp. in Adult Patients with Ac...

MICROORGANISMS 2024 NOV; 12(11):? Article 2151
There is a paucity of information on the prevalence, risk factors, and clinical correlates of people living with HIV (PLWH) who are co-infected with Cryptosporidium spp. in the post-combined antiretroviral therapy era in Ghana. To provide such data, in this observational study, stool samples of 640 HIV-positive and 83 HIV-negative individuals in Ghana were screened for Cryptosporidium spp. Additionally, sociodemographic parameters, clinical symptoms, medication intake, and immunological parameters were assessed. The prevalence of Cryptosporidium spp. was 11.8% (n = 73) in HIV-positive and 1.2% (n = 1) in HIV-negative participants (p < 0.001). Within the group of HIV-positive participants, the prevalence reached 26.0% in patients with CD4+ T cell counts below 200 cells/mu L and 46.2% in the subgroup with CD4+ T cell counts below 50 cells/mu L. The frequencies of the clinical manifestation of weight loss and gastrointestinal symptoms were significantly higher in patients with Cryptosporidium spp. compared to those without co-infection (45.8% vs. 21.4%, p < 0.001 and 22.2% vs. 12.2%, p = 0.031, respectively). In the modern post-cART era, the acquisition of Cryptosporidium spp. among PLWH in Ghana is driven largely by the degree of immunosuppression. Access to cART and screening for Cryptosporidium spp. as part of routine care might help control and reduce the burden of the infection.