Processing and intracellular location of human astrovirus non-structural proteins.
Human astrovirus (HAst) non-structural polyproteins are encoded in two open reading frames linked in expression by a ribosomal frameshifting event. The first of these (ORF 1a) specifies the serine protease, whilst the second (ORF 1b) encodes the virus RNA-dependent RNA polymerase. The ORF 1a product contains an unusual motif for small RNA viruses which could potentially direct proteins to the cell nucleus. We have expressed part of ORF 1a containing this motif and the whole of ORF 1b separately in recombinant baculovirus and raised specific antisera to each. We now report that expressed proteins from ORF 1a accumulate in the nucleus of both baculovirus-infected insect cells and HAst-infected CaCo-2 cells. In contrast the products of ORF 1b remain predominantly cytoplasmic.
Willcocks
Margaret M
MM
School of Biological Sciences, University of Surrey, Guildford GU2 5XH, UK1.
Boxall
Angela S
AS
School of Biological Sciences, University of Surrey, Guildford GU2 5XH, UK1.
Carter
Michael J
MJ
School of Biological Sciences, University of Surrey, Guildford GU2 5XH, UK1.
D000818:Animals; D018938:Caco-2 Cells; D002460:Cell Line; D006801:Humans; D007424:Intracellular Fluid / Q000378:metabolism; D001257:Mamastrovirus / Q000235:genetics / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics / Q000378:metabolism*; D011817:Rabbits; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D018411:Spodoptera / Q000166:cytology; D017361:Viral Nonstructural Proteins / Q000235:genetics / Q000378:metabolism*
D017361:Viral Nonstructural Proteins; D012324:RNA-Dependent RNA Polymerase; D012697:Serine Endopeptidases