Identification and subcellular localization of a 41 kDa, polyprotein 1ab processing product in human coronavirus 229E-infected cells.
The translation products of the human coronavirus (HCV) 229E open reading frames 1a and 1b, the polyproteins 1a and 1ab, are processed by virus-encoded proteinases. One of the key enzymes in this process is a chymotrypsin-like enzyme, the 3C-like proteinase. In this study we have identified an ORF 1b-encoded, 41 kDa processing product in HCV 229E-infected cells by using a monoclonal antibody with defined specificity. We show that this polypeptide is released from polyprotein 1ab by 3C-like proteinase-mediated cleavage of the peptide bonds Gln-6110/Gly-6111 and Gln-6458/Ser-6459. Also, we have investigated the subcellular localization of the 41 kDa processing product. Immunofluorescence microscopy revealed a punctate, perinuclear distribution of the 41 kDa polypeptide in infected cells and an identical subcellular localization was observed for three additional pp1ab-derived polypeptides. In contrast, the virus nucleocapsid protein showed a homogeneous cytoplasmic localization.
Heusipp
G
G
Institute of Virology, University of Würzburg, Germany.
Grötzinger
C
C
Herold
J
J
Siddell
S G
SG
Ziebuhr
J
J
D000911:Antibodies, Monoclonal; D002460:Cell Line; D017934:Coronavirus / Q000502:physiology*; D028941:Coronavirus 229E, Human; D018352:Coronavirus Infections / Q000821:virology*; D010450:Endopeptidases / Q000378:metabolism; D006801:Humans; D016366:Open Reading Frames / Q000235:genetics; D011499:Protein Processing, Post-Translational; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*; D014779:Virus Replication
D000911:Antibodies, Monoclonal; D014764:Viral Proteins; D010450:Endopeptidases