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  • Mogensen Thorsen posted an update 5 hours, 4 minutes ago

    Skeletal muscle is one of the most important organs of the animal body. Long noncoding RNAs (lncRNAs) play a crucial role in the regulation of skeletal muscle development via several mechanisms. We recently identified lnc-ORA in a search for lncRNAs that influence adipogenesis, finding it impacted adipocyte differentiation by regulating the PI3K/AKT/mTOR pathway. However, whether lnc-ORA has additional roles, specifically in skeletal muscle myogenesis, is not known. Here, we found that lnc-ORA was significantly differentially expressed with age in mouse skeletal muscle tissue and predominantly located in the cytoplasm. Overexpression of lnc-ORA promoted C2C12 myoblast proliferation and inhibited myoblast differentiation. In contrast, lnc-ORA knockdown repressed myoblast proliferation and facilitated myoblast differentiation. Interestingly, silencing of lnc-ORA rescued dexamethasone (Dex)-induced muscle atrophy in vitro. Furthermore, adeno-associated virus 9 (AAV9)-mediated overexpression of lnc-ORA decreased muscle mass and the cross-sectional area of muscle fiber by upregulating the levels of muscle atrophy-related genes and downregulating the levels of myogenic differentiation-related genes in vivo. Mechanistically, lnc-ORA inhibited skeletal muscle myogenesis by acting as a sponge of miR-532-3p, which targets the phosphatase and tensin homologue (PTEN) gene; the resultant changes in PTEN suppressed the phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) signaling pathway. Additionally, lnc-ORA interacted with insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) and reduced the stability of myogenesis genes such as myogenic differentiation 1 (MyoD) and myosin heavy chain (MyHC). Collectively, these findings indicate that lnc-ORA could be a novel underlying regulator of skeletal muscle development.The recent discovery of the cancer-associated E76K mutation in histone H2B (H2BE76-to-K) in several types of cancers revealed a new class of oncohistone. H2BE76K weakens the stability of histone octamers, alters gene expression, and promotes colony formation. However, the mechanism linking the H2BE76K mutation to cancer development remains largely unknown. In this study, we knock-in the H2BE76K mutation in MDA-MB-231 breast cancer cells using CRISPR/Cas9 and show that the E76K mutant histone H2B preferentially localizes to genic regions. Interestingly, genes upregulated in the H2BE76K mutant cells are enriched for the E76K mutant H2B and are involved in cell adhesion and proliferation pathways. We focused on one H2BE76K target gene, ADAM19 (A Disintegrin And Metalloproteinase domain-containing protein 19), a gene highly expressed in various human cancers including breast invasive carcinoma, and demonstrate that H2BE76K directly promotes ADAM19 transcription by facilitating efficient transcription along the gene body. ADAM19 depletion reduced the colony formation ability of the H2BE76K mutant cells whereas wildtype MDA-MB-231 cells overexpressing ADAM19 mimics the colony formation phenotype of the H2BE76K mutant cells. Collectively, our data demonstrate the mechanism by which H2BE76K deregulates the expression of genes that control oncogenic properties through a combined effect of its specific genomic localization and nucleosome destabilization effect.Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerge during the last months of 2019, expanding throughout the world as a highly transmissible infectious illness designated as COVID-19. Vaccines have now appeared, but the challenges in producing sufficient material and distributing them around the world means that effective treatments to limit infection and improve recovery are still urgently needed. This review is focused on the relevance of different glycobiological molecules that could potentially serve as or inspire therapeutic tools during SARS-CoV-2 infection. Diphenyleneiodonium solubility dmso As such, we highlight the glycobiology of the SARS-CoV-2 infection process, where glycans on viral proteins and on host glycosaminoglycans have critical roles in efficient infection. We also take notice of the glycan-binding proteins involved in the infective capacity of virus and in human defense. In addition, we critically evaluate the glycobiological contribution of candidate drugs for COVID-19 therapy such as glycans for vaccines, anti-glycan antibodies, recombinant lectins, lectin inhibitors, glycosidase inhibitors, polysaccharides, and numerous glycosides, emphasizing some opportunities to repurpose FDA-approved drugs. For the next generation drugs suggested here, biotechnological engineering making new probes to block the SARS-CoV-2 infection might be based in the essential glycobiological insight on glycosyltransferases, glycans, glycan-binding proteins and glycosidases related to this pathology.Microbial plant pathogens secrete effector proteins which manipulate the host to promote infection. Effectors can be recognised by plant intracellular nucleotide-binding leucine-rich repeat (NLR) receptors, initiating an immune response. The AVR-Pik effector from the rice blast fungus Magnaporthe oryzae is recognised by a pair of rice NLR receptors, Pik-1 and Pik-2. Pik-1 contains a non-canonical integrated heavy metal-associated (HMA) domain, which directly binds AVR-Pik to activate plant defences. The host targets of AVR-Pik are also HMA domain-containing proteins, namely heavy metal-associated isoprenylated plant proteins (HIPPs) and heavy metal-associated plant proteins (HPPs). Here, we demonstrate that one of these targets interacts with a wider set of AVR-Pik variants compared to the Pik-1 HMA domains. We define the biochemical and structural basis of the interaction between AVR-Pik and OsHIPP19, and compare the interaction to that formed with the HMA domain of Pik-1. Using analytical gel filtration and surface plasmon resonance, we show that multiple AVR-Pik variants, including the stealthy variants AVR-PikC and AVR-PikF which do not interact with any characterised Pik-1 alleles, bind to OsHIPP19 with nanomolar affinity. The crystal structure of OsHIPP19 in complex with AVR-PikF reveals differences at the interface that underpin high-affinity binding of OsHIPP19-HMA to a wider set of AVR-Pik variants than achieved by the integrated HMA domain of Pik-1. Our results provide a foundation for engineering the HMA domain of Pik-1 to extend binding to currently unrecognised AVR-Pik variants and expand disease resistance in rice to divergent pathogen strains.