Characterizing the interactions that SARS-CoV-2 viral RNAs make with host cell proteins during infection can improve our understanding of viral RNA functions and the host innate immune response. ...Using RNA antisense purification and mass spectrometry, we identified up to 104 human proteins that directly and specifically bind to SARS-CoV-2 RNAs in infected human cells. We integrated the SARS-CoV-2 RNA interactome with changes in proteome abundance induced by viral infection and linked interactome proteins to cellular pathways relevant to SARS-CoV-2 infections. We demonstrated by genetic perturbation that cellular nucleic acid-binding protein (CNBP) and La-related protein 1 (LARP1), two of the most strongly enriched viral RNA binders, restrict SARS-CoV-2 replication in infected cells and provide a global map of their direct RNA contact sites. Pharmacological inhibition of three other RNA interactome members, PPIA, ATP1A1, and the ARP2/3 complex, reduced viral replication in two human cell lines. The identification of host dependency factors and defence strategies as presented in this work will improve the design of targeted therapeutics against SARS-CoV-2.
Neurotransmitter release as well as structural and functional dynamics at the presynaptic active zone (PAZ) comprising synaptic vesicles attached to the presynaptic plasma membrane are mediated and ...controlled by its proteinaceous components. Here we describe a novel experimental design to immunopurify the native PAZ-complex from individual mouse brain regions such as olfactory bulb, hippocampus, and cerebellum with high purity that is essential for comparing their proteome composition. Interestingly, quantitative immunodetection demonstrates significant differences in the abundance of prominent calcium-dependent PAZ constituents. Furthermore, we characterized the proteomes of the immunoisolated PAZ derived from the three brain regions by mass spectrometry. The proteomes of the release sites from the respective regions exhibited remarkable differences in the abundance of a large variety of PAZ constituents involved in various functional aspects of the release sites such as calcium homeostasis, synaptic plasticity and neurogenesis. On the one hand, our data support an identical core architecture of the PAZ for all brain regions and, on the other hand, demonstrate that the proteinaceous composition of their presynaptic active zones vary, suggesting that changes in abundance of individual proteins strengthen the ability of the release sites to adapt to specific functional requirements.
The proinflammatory cytokine IL-36γ is highly expressed in epithelial cells and is a pivotal mediator of epithelial inflammation. In particular, IL-36γ is strongly associated with the inflammatory ...skin disease psoriasis. As with other IL-1 cytokines, IL-36γ is expressed as an inactive precursor and must be processed by specific proteases to become bioactive. Our aim therefore was to identify protease/s capable of IL-36γ activation and explore the importance of this activation in psoriasis. Using a keratinocyte-based activity assay in conjunction with small-molecule inhibitors and siRNA gene silencing, cathepsin S was identified as the major IL-36γ–activating protease expressed by epithelial cells. Interestingly, cathepsin S activity was strongly up-regulated in samples extracted from psoriasis patients relative to healthy controls. In addition, IL-36γ–Ser18, identified as the main product of cathepsin S-dependent IL-36γ cleavage, induced psoriasiform changes in human skin-equivalent models. Together, these data provide important mechanistic insights into the activation of IL-36γ and highlight that cathepsin S-mediated activation of IL-36γ may be important in the development of numerous IL-36γ–driven pathologies, in addition to psoriasis.
Deregulated expression of MYC enhances glutamine utilization and renders cell survival dependent on glutamine, inducing “glutamine addiction”. Surprisingly, colon cancer cells that express high ...levels of MYC due to WNT pathway mutations are not glutamine‐addicted but undergo a reversible cell cycle arrest upon glutamine deprivation. We show here that glutamine deprivation suppresses translation of endogenous MYC via the 3′‐UTR of the MYC mRNA, enabling escape from apoptosis. This regulation is mediated by glutamine‐dependent changes in adenosine‐nucleotide levels. Glutamine deprivation causes a global reduction in promoter association of RNA polymerase II (RNAPII) and slows transcriptional elongation. While activation of MYC restores binding of MYC and RNAPII function on most promoters, restoration of elongation is imperfect and activation of MYC in the absence of glutamine causes stalling of RNAPII on multiple genes, correlating with R‐loop formation. Stalling of RNAPII and R‐loop formation can cause DNA damage, arguing that the MYC 3′‐UTR is critical for maintaining genome stability when ribonucleotide levels are low.
Synopsis
Glutamine and its metabolite adenosine control translation of MYC via the 3′‐UTR, linking RNA polymerase II (RNAPII) function to nucleotide availability. Bypassing this control induces stalling of RNAPII and R‐loop formation.
Glutamine deprivation inhibits translation of MYC via the 3′‐UTR.
The 3′‐UTR allows MYC‐driven tumour cells to escape from glutamine addiction.
Adenosine is the critical downstream effector of glutamine.
Control of MYC levels by adenosine links global RNAPII function to nucleoside availability.
Glutamine and its metabolite adenosine control translation of MYC via the 3′‐UTR, linking RNA polymerase II (RNAPII) function to nucleotide availability. Bypassing this control induces stalling of RNAPII and R‐loop formation.
The proinflammatory cytokine IL-36gamma is highly expressed in epithelial cells and is a pivotal mediator of epithelial inflammation. In particular, IL-36gamma is strongly associated with the ...inflammatory skin disease psoriasis. As with other IL-1 cytokines, IL-36gamma is expressed as an inactive precursor and must be processed by specific proteases to become bioactive. Our aim therefore was to identify protease/s capable of IL-36gamma activation and explore the importance of this activation in psoriasis. Using a keratinocyte-based activity assay in conjunction with small-molecule inhibitors and siRNA gene silencing, cathepsin S was identified as the major IL-36gamma-activating protease expressed by epithelial cells. Interestingly, cathepsin S activity was strongly up-regulated in samples extracted from psoriasis patients relative to healthy controls. In addition, IL-36gamma-Ser18, identified as the main product of cathepsin S-dependent IL-36gamma cleavage, induced psoriasiform changes in human skin-equivalent models. Together, these data provide important mechanistic insights into the activation of IL-36gamma and highlight that cathepsin S-mediated activation of IL-36gamma may be important in the development of numerous IL-36gamma-driven pathologies, in addition to psoriasis.
Welche Einrichtung hat in den letzten Jahren keinen massiven Stellenabbau im Pflegepersonal vollzogen? Gleichzeitig haben sich durch die demografischen Entwicklung und die modernen medizintechnischen ...Möglichkeiten, aber auch durch ein zunehmendes Gesundheitsbewusstsein der Bevölkerung die Patientenzahlen deutlich erhöht. Die damit einhergehende Fallzahlsteigerung wird nur zum Teil durch Verweildauerreduktionen aufgewogen. Was daraus resultiert ist eine massive Leistungsverdichtung in der stationären Krankenversorgung.
Wir widmen uns der Frage, wie in einem solchen Umfeld durch integrierte Organisationsmaßnahmen auf Station ruhigere Abläufe zu erreichen sind.
Die vorliegende Ausgabe des Medienbriefs präsentiert das Thema Englisch lernen mit Computerunterstützung anhand einiger Praxisbeispiele. Das Themenspektrum reicht vom Einsatz digitaler Lernwerkzeuge ...im Englischunterricht über Portfolioarbeit bis zum Einsatz von Lernplattformen. (DIPF/Bg.).
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