Inhibition of host ER glucosidase activity prevents Golgi processing of virion-associated bovine viral diarrhea virus E2 glycoproteins and reduces infectivity of secreted virions.
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.
Jordan
Robert
R
Department of Biochemistry and Molecular Pharmacology, Thomas Jefferson University, Doylestown, Pennsylvania, 18901, USA. robert.jordan@mail.tju.edu
Nikolaeva
Olga V
OV
Wang
Lijuan
L
Conyers
Bertha
B
Mehta
Anand
A
Dwek
Raymond A
RA
Block
Timothy M
TM
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
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