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A Novel Sorting Signal for Intracellular Localization Is Present in the S Protein of a Porcine Coronavirus but Absent from Severe Acute Respiratory Syndrome-associated Coronavirus
Coronaviruses (CoV) mature by a budding process at intracellular membranes. Here we showed that the major surface protein S of a porcine CoV (transmissible gastroenteritis virus) is not transported to the cell surface but is retained intracellularly. Site-directed mutagenesis indicated that a tyrosi...
Autores principales: | , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
ASBMB. Currently published by Elsevier Inc; originally published by American Society for Biochemistry and Molecular Biology.
2004
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8060824/ https://www.ncbi.nlm.nih.gov/pubmed/15304515 http://dx.doi.org/10.1074/jbc.M407233200 |
Sumario: | Coronaviruses (CoV) mature by a budding process at intracellular membranes. Here we showed that the major surface protein S of a porcine CoV (transmissible gastroenteritis virus) is not transported to the cell surface but is retained intracellularly. Site-directed mutagenesis indicated that a tyrosine-dependent signal (YXXI) in the cytoplasmic tail is essential for intracellular localization of the S protein. Surface expression of mutant proteins was evident by immunofluorescence analysis and surface biotinylation. Intracellularly retained S proteins only contained endoglycosidase H-sensitive N-glycans, whereas mutant proteins that migrated to the plasma membrane acquired N-linked oligosaccharides of the complex type. Corresponding tyrosine residues are present in the cytoplasmic tails of the S proteins of other animal CoV but not in the tail portion of the S protein of severe acute respiratory syndrome (SARS)-CoV. Changing the SEPV tetrapeptide in the cytoplasmic tail to YEPI resulted in intracellular retention of the S protein of SARS-CoV. As the S proteins of CoV have receptor binding and fusion activities and are the main target of neutralizing antibodies, the differences in the transport behavior of the S proteins suggest different strategies in the virus host interactions between SARS-CoV and other coronaviruses. |
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