Previous Article | Next Article ![]()
Journal of Virology, August 2000, p. 6760-6768, Vol. 74, No. 15
Institute of Molecular Biology,
Friedrich-Loeffler-Institutes, Federal Research Centre for Virus
Diseases of Animals, D-17498 Insel Riems, Germany
Received 24 January 2000/Accepted 3 May 2000
A transient transfection-fusion assay was established to
investigate membrane fusion mediated by pseudorabies virus
(PrV) glycoproteins. Plasmids expressing PrV glycoproteins
under control of the immediate-early 1 promoter-enhancer of human
cytomegalovirus were transfected into rabbit kidney cells, and the
extent of cell fusion was quantitated 27 to 42 h after
transfection. Cotransfection of plasmids encoding PrV
glycoproteins B (gB), gD, gH, and gL resulted in formation
of polykaryocytes, as has been shown for homologous proteins of herpes
simplex virus type 1 (HSV-1) (A. Turner, B. Bruun, T. Minson, and H. Browne, J. Virol. 72:873-875, 1998). However, in contrast to
HSV-1, fusion was also observed when the gD-encoding plasmid was
omitted, which indicates that PrV gB, gH, and gL are sufficient to
mediate fusion. Fusogenic activity was enhanced when a
carboxy-terminally truncated version of gB (gB-008) lacking the
C-terminal 29 amino acids was used instead of wild-type gB. With
gB-008, only gH was required in addition for fusion. A very rapid and
extended fusion was observed after cotransfection of plasmids encoding
gB-008 and gDH, a hybrid protein consisting of the N-terminal 271 amino
acids of gD fused to the 590 C-terminal amino acids of gH. This protein
has been shown to substitute for gH, gD, and gL function in the
respective viral mutants (B. G. Klupp and T. C. Mettenleiter,
J. Virol. 73:3014-3022, 1999). Cotransfection of plasmids
encoding PrV gC, gE, gI, gK, and UL20 with gB-008 and gDH had no effect
on fusion. However, inclusion of a gM-expressing plasmid strongly
reduced the extent of fusion. An inhibitory effect was also observed
after inclusion of plasmids encoding gM homologs of equine herpesvirus
1 or infectious laryngotracheitis virus but only in conjunction with
expression of the gM complex partner, the gN homolog. Inhibition by PrV
gM was not limited to PrV glycoprotein-mediated fusion but
also affected fusion induced by the F protein of bovine respiratory
syncytial virus, indicating a general mechanism of fusion inhibition by gM.
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Pseudorabies Virus Glycoprotein M Inhibits
Membrane Fusion
*
Corresponding author. Mailing address: Institute of
Molecular Biology, Friedrich-Loeffler-Institutes, Federal
Research Centre for Virus Diseases of Animals, D-17498 Insel
Riems, Germany. Phone: 49-38351-7250. Fax: 49-38351-7151. E-mail:
mettenleiter{at}rie.bfav.de.
This article has been cited by other articles:
| J. Bacteriol. | Mol. Cell. Biol. | Microbiol. Mol. Biol. Rev. |
|---|
| Clin. Vaccine Immunol. | ALL ASM JOURNALS |
|---|