Publications by authors named "Uriu K"
Article Synopsis
- Researchers created a mathematical model to illustrate how Per2 and Per2AS mutually repress each other, influencing circadian oscillation's amplitude and period through negative feedback.
- The new model aligns with experimental data better than previous models and can help analyze other sense-antisense RNA interactions in the future.
Virological characteristics of the SARS-CoV-2 Omicron EG.5.1 variant.
Microbiol Immunol
September 2024
Article Synopsis
- A new variant of SARS-CoV-2, called EG.5.1, is spreading rapidly and has been studied using various scientific methods to understand its features.
- Key mutations in EG.5.1, specifically S:F456L and ORF9b:I5T, enhance its viral fitness compared to other variants like XBB.1.5.
- Structural differences were found in the spike proteins of EG.5.1 versus XBB.1.5, and the research helps us understand the evolution of emerging viruses that can affect human health.
Article Synopsis
- Researchers isolated a coronavirus called BANAL-20-236 (B236) from Malayan horseshoe bats and found it lacks a key site in its spike protein that is present in SARS-CoV-2.
- * They compared B236's characteristics using human-derived cells and hamster infection experiments, discovering it's less pathogenic and grows slower in respiratory cells compared to SARS-CoV-2, but grows better in intestinal cells.
- * The study suggests that SC2r-CoVs like B236 may primarily replicate in the intestines rather than the respiratory system, supporting prior findings about its behavior in other models.
Antisense transcripts are a unique group of non-coding RNAs that are transcribed from the opposite strand of a sense coding gene in an antisense orientation. Even though they do not encode a protein, these transcripts play a regulatory role in a variety of biological processes, including circadian rhythms. We and others found an antisense transcript, , that is transcribed from the strand opposite the sense transcript ( ) and exhibits a rhythmic and antiphasic expression pattern compared to in mouse.
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- The emergence of a new Variant of Interest, XBB.1.5, is linked to mutations from the pre-existing variant XBB.1, specifically an S486P spike mutation and a nonsense mutation in ORF8.
- Phylogenetic analysis indicates that XBB.1.5 maintains similar immune escape abilities compared to XBB.1, and structural studies reveal that the spike proteins of both variants are largely similar.
- Research involving hamsters shows that the ORF8 nonsense mutation in XBB.1.5 reduces MHC suppression and results in lower virulence in this variant compared to XBB.1.
The pandemic HIV-1, HIV-1 group M, emerged from a single spillover event of its ancestral lentivirus from a chimpanzee. During human-to-human spread worldwide, HIV-1 diversified into multiple subtypes. Here, our interdisciplinary investigation mainly sheds light on the evolutionary scenario of the viral budding system of HIV-1 subtype C (HIV-1C), a most successfully spread subtype.
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- In late 2023, the SARS-CoV-2 BA.2.86 variant emerged alongside the dominant XBB descendants like EG.5.1, distinguishing itself with over 30 mutations in its spike protein.
- Modeling showed BA.2.86 has a higher reproduction number compared to EG.5.1, suggesting it spreads more easily.
- Despite its increased spread, BA.2.86 demonstrated lower pathogenicity and replication capacity in hamsters, indicating it may be less severe, while remaining sensitive to four existing antiviral treatments.
Most SARS-CoV-2 proteins are translated from subgenomic RNAs (sgRNAs). While the majority of these sgRNAs are monocistronic, some viral mRNAs encode more than one protein. One example is the ORF3a sgRNA that also encodes ORF3c, an enigmatic 41-amino-acid peptide.
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- Most research on SARS-CoV-2 variants has concentrated on mutations in spike proteins that influence how the virus infects and spreads.
- This study highlights that there are also significant mutations outside of the spike protein that can affect the virus's behavior.
- Specifically, the study found that certain mutations in the Omicron BA.2 variant, including one in the spike protein and another further down the gene, play crucial roles in defining its characteristics.
The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variants has led to concerns that ancestral SARS-CoV-2-based vaccines may not be effective against newly emerging Omicron subvariants. The concept of "imprinted immunity" suggests that individuals vaccinated with ancestral virus-based vaccines may not develop effective immunity against newly emerging Omicron subvariants, such as BQ.1.
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- In late 2022, the SARS-CoV-2 Omicron subvariant XBB emerged from the recombination of two existing BA.2 lineages, BJ.1 and BM.1.1.1, during the summer of 2022.
- XBB.1 shows strong resistance to vaccines designed for BA.2/5 and has increased fusogenicity, meaning it can fuse with human cells more efficiently due to changes in its spike protein.
- Research indicates that while XBB.1 is pathogenic, its disease-causing potential in male hamsters is similar to or lower than that of the BA.2.75 variant, marking a notable adaptation in virus evolution through recombination.
Article Synopsis
- In late 2022, several Omicron subvariants emerged globally, characterized by specific amino acid changes in their spike proteins, indicating convergent evolution.
- The study highlights a problematic lineage, BQ.1.1, which shows higher viral fitness due to five critical amino acid substitutions and better evasion of immune responses compared to the BA.5 subvariant.
- In tests on hamsters, BQ.1.1 demonstrated lower pathogenicity than BA.5, revealing insights into the evolutionary patterns of Omicron subvariants up to 2022.
The metameric pattern of somites is created based on oscillatory expression of clock genes in presomitic mesoderm. However, the mechanism for converting the dynamic oscillation to a static pattern of somites is still unclear. Here, we provide evidence that Ripply/Tbx6 machinery is a key regulator of this conversion.
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