ArticleJournal of virology2009
Proteolytic activation of the spike protein at a novel RRRR/S motif is implicated in furin-dependent entry, syncytium formation, and infectivity of coronavirus infectious bronchitis virus in cultured cells.
Article in Journal of virology, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 112 papers.
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Who cites it
112 citing papers in PubMed, 183 citations in OpenAlex.
- Disruption of the S1/S2 multibasic cleavage site attenuates infectious bronchitis virus, while S2' partially restores viral virulence and expands tissue tropism.Journal of virology · 2026Article
- TMPRSS2-mediated coronavirus spike activation and inhibition.Nature structural & molecular biology · 2026Article
- Accumulation of mutations in nsp4, E, and the S2 subunit underlies mammalian cell tropism expansion and virulence attenuation of avian coronavirus.PLoS pathogens · 2026Article
- Interaction of coronavirus E protein with BRD2 plays important regulatory roles in viral replication and induction of pro-inflammatory response.Journal of virology · 2026Article
- Mutations to the HCoV-229E spike have counterbalancing effects on serum antibody neutralization and receptor binding.bioRxiv : the preprint server for biology · 2026Article
- Serine protease-driven entry and S2 ' cleavage flexibility of feline coronavirus during feline enterocyte infections.PLoS pathogens · 2026Article
- Engineering Anti-Tumor Immunity: An Immunological Framework for mRNA Cancer Vaccines.Vaccines · 2025Review
- Two novel conserved linear B-cell epitopes identified in the S2 subunit of the infectious bronchitis virus spike protein.Virus research · 2025Article
- A comprehensive PDCoV-host proteome interaction map reveals potential antiviral targets.PLoS pathogens · 2025Article
- The role of the S1 gene in glandular stomach pathogenesis and tropism of infectious bronchitis virus H120 strain in poultry.Microbiology spectrum · 2025Article
- Development and Protective Efficacy of a Novel Nanoparticle Vaccine for Gammacoronavirus Avain Infectious Bronchitis Virus.Vaccines · 2025Article
- Identification of B-Cell Epitopes Located on the Surface of the S1 Protein of Infectious Bronchitis Virus M41 Strains.Viruses · 2025Article
- Modulation of viral replication, autophagy and apoptosis by induction and mutual regulation of transcription factors EB and E3 during coronavirus infection.Frontiers in microbiology · 2025Article
- Article
- Molecular characterization of a novel variant of infectious bronchitis virus from field outbreaks in backyard chicken population of North East India.Virus genes · 2024Article
- Development and characterization of a recombinant Senecavirus A expressing enhanced green fluorescent protein.Frontiers in microbiology · 2024Article
- SARS-CoV-2 Syncytium under the Radar: Molecular Insights of the Spike-Induced Syncytia and Potential Strategies to Limit SARS-CoV-2 Replication.Journal of clinical medicine · 2023Review
- Tight junction protein occludin is an internalization factor for SARS-CoV-2 infection and mediates virus cell-to-cell transmission.Proceedings of the National Academy of Sciences of the United States of America · 2023Article
- Aptamer-Assisted Proximity Ligation Assay for Sensitive Detection of Infectious Bronchitis Coronavirus.Microbiology spectrum · 2023Article
- Natural selection differences detected in key protein domains between non-pathogenic and pathogenic Feline Coronavirus phenotypes.bioRxiv : the preprint server for biology · 2023Article
52 more citing papers are in PubMed but not listed here.
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Authors and funding
2 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
The spike (S) protein of the coronavirus (CoV) infectious bronchitis virus (IBV) is cleaved into S1 and S2 subunits at the furin consensus motif RRFRR(537)/S in virus-infected cells. In this study, we observe that the S2 subunit of the IBV Beaudette strain is additionally cleaved at the second furin site (RRRR(690)/S) in cells expressing S constructs and in virus-infected cells. Detailed time course experiments showed that a peptide furin inhibitor, decanoyl-Arg-Val-Lys-Arg-chloromethylketone, blocked both viral entry and syncytium formation. Site-directed mutagenesis studies revealed that the S1/S2 cleavage by furin was not necessary for, but could promote, syncytium formation by and infectivity of IBV in Vero cells. In contrast, the second site is involved in the furin dependence of viral entry and syncytium formation. Mutations of the second site from furin-cleavable RRRR/S to non-furin-cleavable PRRRS and AAARS, respectively, abrogated the furin dependence of IBV entry. Instead, a yet-to-be-identified serine protease(s) was involved, as revealed by protease inhibitor studies. Furthermore, sequence analysis of CoV S proteins by multiple alignments showed conservation of an XXXR/S motif, cleavable by either furin or other trypsin-like proteases, at a position equivalent to the second IBV furin site. Taken together, these results suggest that proteolysis at a novel XXXR/S motif in the S2 subunit might be a common mechanism for the entry of CoV into cells.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.