Studies on intracellular processing of the capsid protein of human astrovirus serotype 1 in infected cells.
Astroviruses are non-enveloped, positive-strand RNA viruses. Their structural (capsid) protein is processed extracellularly into several smaller fragments which are found on the mature viral particle. In addition, intracellular cleavage of the capsid protein has been proposed. However, analysis of capsid protein processing has been hampered by the lack of antibodies to regions near the N and C termini of the protein. Here we describe the construction of two infectious mutants of human astrovirus serotype 1 (HAstV-1), in which amino acids (aa) 11-30 or aa 783-787, respectively, of the 787 aa capsid protein were replaced by tag sequences. Processing of the tagged capsid proteins in infected Caco-2 cells was analysed by immunoprecipitation with specific reagents directed against the tags or against native internal regions of the capsid protein. No intracellular processing of the capsid protein in infected cells could be detected, while assembled viral particles were readily observed within cells.
Geigenmüller
Ute
U
Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA, USA2.|Department of Medicine, Gastroenterology Section (111-GI), VA Palo Alto Health Care System, 3801 Miranda Avenue, Palo Alto, CA 94304, USA1.
Ginzton
Nancy H
NH
Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA, USA2.|Department of Medicine, Gastroenterology Section (111-GI), VA Palo Alto Health Care System, 3801 Miranda Avenue, Palo Alto, CA 94304, USA1.
Matsui
Suzanne M
SM
Division of Gastroenterology and Hepatology, Stanford University School of Medicine, Stanford, CA, USA2.|Department of Medicine, Gastroenterology Section (111-GI), VA Palo Alto Health Care System, 3801 Miranda Avenue, Palo Alto, CA 94304, USA1.
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000235:genetics; D018938:Caco-2 Cells / Q000821:virology; D002213:Capsid / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D001257:Mamastrovirus / Q000378:metabolism / Q000502:physiology*; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational; D020079:Terminal Repeat Sequences; D019065:Virus Assembly
D000596:Amino Acids