Biology subjects

Tsunoda, Y.

Publications and source records attributed to Tsunoda, Y..

3 recordsLinked to original sources

bioRxiv2024

Coatomer complex I is required for the transport of SARS-CoV-2 progeny virions from the endoplasmic reticulum-Golgi intermediate compartment

SARS-CoV-2 undergoes budding within the lumen of the endoplasmic reticulum-Golgi intermediate compartment (ERGIC) and delivers progeny virions to the cell surface by employing vesicular transport. However, the molecular mechanisms remain poorly understood. Using three-dimensional electron microscopic analysis, such as array tomography and electron tomography, we found that virion-transporting vesicles possessed a coated protein on their membrane and demonstrated that the coated protein was coatomer complex I (COPI). During the later stages of SARS-CoV-2 infection, we observed a notable alteration in the distribution of COPI and ERGIC throughout the cytoplasm. Depletion of COPB2, a key component of COPI, led to the confinement of SARS-CoV-2 structural proteins in the perinuclear region, where progeny virions were accumulated within the ERGIC. While the expression levels of viral proteins within cells were comparable, this depletion significantly reduced the efficiency of virion release, leading to the significant inhibition of viral replication. Hence, our findings suggest COPI as a critical player in facilitating the transport of SARS-CoV-2 progeny virions from the ERGIC. Thus, COPI could be a promising target for the development of antivirals against SARS-CoV-2.

microbiology↗

bioRxiv2023

Genome-scale CRISPR-Cas9 screen identifies novel host factors as potential therapeutic targets for SARS-CoV-2 infection.

Although many host factors important for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection have been reported, the mechanisms by which the virus interacts with host cells remain elusive. Here, we identified tripartite motif containing (TRIM) 28, TRIM33, euchromatic histone lysine methyltransferase (EHMT) 1, and EHMT2 as novel proviral factors involved in SARS-CoV-2 infection by CRISPR-Cas9 screening. We demonstrated that TRIM28 plays a role(s) in viral particle formation and that TRIM33, EHMT1, and EHMT2 are involved in viral transcription and replication using cells with suppressed gene expression. UNC0642, a compound that specifically inhibits the methyltransferase activity of EHMT1/2, strikingly suppressed SARS-CoV-2 growth in cultured cells and reduced disease severity in a hamster infection model. This study suggests that EHMT1/2 may be a novel therapeutic target for SARS-CoV-2 infection.

microbiology↗

bioRxiv2021

Structural insight into Marburg virus nucleoprotein-RNA complex formation

The nucleoprotein (NP) of Marburg virus (MARV), a close relative of Ebola virus (EBOV), encapsidates the single-stranded, negative-sense viral genomic RNA (vRNA) to form the helical NP-RNA complex. The NP-RNA complex serves as a scaffold for the assembly of the nucleocapsid that is responsible for viral RNA synthesis. Although appropriate interactions among NPs and RNA are required for the formation of nucleocapsid, the structural basis of the helical assembly remains largely elusive. Here, we show the structure of the MARV NP-RNA complex determined using cryo-electron microscopy at a resolution of 3.1 [A]. The structures of the asymmetric unit, a complex of an NP and six RNA nucleotides, was very similar to that of EBOV, suggesting that both viruses share common mechanisms for the nucleocapsid formation. Structure-based mutational analysis of both MARV and EBOV NPs identified key residues for the viral RNA synthesis as well as the helical assembly. Importantly, most of the residues identified were conserved in both viruses. These findings provide a structural basis for understanding the nucleocapsid formation and contribute to the development of novel antivirals against MARV and EBOV.

microbiology↗