title: Inhibition of host ER glucosidase activity prevents Golgi processing of virion-associated bovine viral diarrhea virus E2 glycoproteins and reduces infectivity of secreted virions.
abstract: Recently, it was shown that replication of bovine viral diarrhea virus (BVDV) is sensitive to inhibitors of host ER glucosidases. Consistent with these findings, we report that incubation of BVDV-infected MDBK cells with the glucosidase inhibitor n-butyl-deoxynojirimycin (nB-DNJ) reduced BVDV yields by 70- to 100-fold (n = 27), while having no effect on MDBK cell viability. However, the 70- to 100-fold reduction in infectious virus was associated with only a 2-fold reduction in genomic RNA synthesis and secretion of enveloped virus particles. Analysis of secreted virions showed that in the absence of glucosidase inhibitor, approximately 50% of the virion-associated BVDV E2 glycoprotein was resistant to endoglycosidase H (endo H) digestion, whereas intracellular E2 was completely sensitive to endo H digestion. In the presence of glucosidase inhibitor, virion-associated E2 and intracellular E2 were completely sensitive to endo H digestion. Taken together, these results suggest that BVDV is secreted through a Golgi-mediated pathway and that host ER glucosidase activity is required for production of infectious virions and Golgi processing of envelope E2 protein during virus egress.
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, Thomas Jefferson University, Doylestown, Pennsylvania, 18901, USA. robert.jordan@mail.tju.edu
authors.forename: Robert
authors.initials: R
authors.lastname: Jordan
authors.forename: Olga V
authors.initials: OV
authors.lastname: Nikolaeva
authors.forename: Lijuan
authors.initials: L
authors.lastname: Wang
authors.forename: Bertha
authors.initials: B
authors.lastname: Conyers
authors.forename: Anand
authors.initials: A
authors.lastname: Mehta
authors.forename: Raymond A
authors.initials: RA
authors.lastname: Dwek
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Block
mesh_terms: D017485:1-Deoxynojirimycin / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000517:prevention & control; D002417:Cattle; D002460:Cell Line; D001908:Diarrhea Viruses, Bovine Viral / Q000187:drug effects*; D004721:Endoplasmic Reticulum / Q000201:enzymology*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005959:Glucosidases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000037:antagonists & inhibitors; D006056:Golgi Apparatus / Q000502:physiology* / Q000821:virology; D006596:Hexosaminidases; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D014759:Viral Envelope Proteins / Q000378:metabolism*; D014771:Virion / Q000187:drug effects* / Q000378:metabolism / Q000472:pathogenicity; D014779:Virus Replication / Q000187:drug effects
chemical_list: D004791:Enzyme Inhibitors; D006023:Glycoproteins; D014759:Viral Envelope Proteins; C076551:gp53, bovine viral diarrhea virus; D017485:1-Deoxynojirimycin; C059896:miglustat; D005959:Glucosidases; D006026:Glycoside Hydrolases; D006596:Hexosaminidases; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase