Exposure of Semliki Forest virus-infected baby hamster kidney cells to low pH leads to a proton influx and a rapid depletion of intracellular ATP which in turn prevents cell-cell fusion

1988 ◽  
Vol 99 (1-2) ◽  
pp. 111-115 ◽  
Author(s):  
C. Kempf ◽  
M. R. Michel ◽  
U. Kohler ◽  
H. Koblet
Keyword(s):  
Cell Fusion ◽  
Semliki Forest Virus ◽  
Low Ph ◽  
Kidney Cells ◽  
Baby Hamster Kidney ◽  
Intracellular Atp ◽  
Baby Hamster Kidney Cells ◽  
Cell Cell

scholarly journals Effects of multiple amino acids of the parainfluenza virus 5 fusion protein on its haemagglutinin–neuraminidase-independent fusion activity

2009 ◽  
Vol 90 (2) ◽  
pp. 405-413 ◽  
Author(s):  
Morihiro Ito ◽  
Machiko Nishio ◽  
Mitsuo Kawano ◽  
Hiroshi Komada ◽  
Yasuhiko Ito ◽  
...  
Keyword(s):  
Amino Acids ◽  
Fusion Protein ◽  
Cell Fusion ◽  
Parainfluenza Virus ◽  
Kidney Cells ◽  
Fusion Activity ◽  
Baby Hamster Kidney ◽  
F Protein ◽  
Parainfluenza Virus 5 ◽  
Baby Hamster Kidney Cells

The fusion (F) protein of parainfluenza virus 5 (PIV-5) strain W3A is able to induce cell fusion when it is expressed alone in baby hamster kidney cells, whilst the F protein of PIV-5 strain WR induces cell fusion only when co-expressed with the haemagglutinin–neuraminidase (HN) protein. It has been shown previously that when Leu-22 of the WR F protein is replaced with the W3A F counterpart (Pro-22), the resulting mutant L22P exhibits HN-independent fusion activity. Furthermore, previous chimeric analysis between L22P and the F protein of PIV-5 strain T1 has suggested that Glu-132 also contributes to the HN-independent fusion activity of L22P. It was shown here that substitution of Glu-132 of L22P with various amino acids including the T1 F protein counterpart (Lys-132) resulted in a reduction in fusion activity, whereas substitution with Asp was the exception in being tolerated. Interestingly, reduced fusion activity of an L22P mutant that harboured the E132K substitution could be restored by an additional D416K substitution but not by a D416E mutation, suggesting that the presence of the same charge at positions 132 and 416 is important for the HN-independent fusion activity. In contrast, substitution of Leu-22 of the WR F protein with various amino acids except those with aliphatic side chains resulted in acquisition of fusion activity, suggesting that the HN dependence of the WR F protein in the induction of cell fusion is attributable to the hydrophobicity of Leu-22. These results indicate that at least three amino acids are involved in the HN-independent fusion activity of the PIV-5 F protein.

Inhibition of Phosphatidylethanolamine Biosynthesis in Baby Hamster Kidney-21 Cells Infected with Semliki Forest Virus

1975 ◽  
Vol 53 (9) ◽  
pp. 950-957 ◽  
Author(s):  
Dennis E. Vance ◽  
Rita M. Dahlke
Keyword(s):  
Viral Infection ◽  
Nadh Dehydrogenase ◽  
Semliki Forest Virus ◽  
Kidney Cells ◽  
Baby Hamster Kidney ◽  
Microsomal Enzymes ◽  
Similar Reduction ◽  
Intact Cells ◽  
Infected Cells ◽  
Baby Hamster Kidney Cells

Semliki Forest virus inhibits phosphatidylethanolamine biosynthesis in baby hamster kidney-21 cells 6 h after infection. Viral infection reduced the incorporation of [1,2-14C]-ethanolamine into intact cells by approximately 50%. A similar reduction in the activity of the ethanolaminephosphotransferase (EC 2.7.8.1) was also observed. The apparent Km for CDPethanolamine was 60 μM for the microsomal enzymes from infected or mock-infected cells. In addition, exogenous diglyceride only stimulated by 1.5-fold the ethanolaminephosphotransferase from virus- or mock-infected cells, whereas the same diglyceride preparations stimulated the cholinephosphotransferase (EC 2.7.8.2) from baby hamster kidney cells by sixfold. Generation of endogenous diglyceride by pretreatment of the microsomes with phospholipase C (EC 3.1.4.3) stimulated the activity of the cholinephosphotransferase but not the ethanolaminephosphotransferase. Semliki Forest virus does not inhibit all microsomal enzymes, since the activities of NADH- K3Fe(CN)6 reductase and NADH dehydrogenase (EC 1.6.99.3) were not affected. The ethanolaminephosphotransferase from virus- and mock-infected cells showed similar profiles of activity as a function of temperature; this result and other studies suggest that that membranous environment of the ethanolaminephosphotransferase was not significantly modified by the virus.

scholarly journals Mechanisms of mutations inhibiting fusion and infection by Semliki Forest virus.

1996 ◽  
Vol 134 (4) ◽  
pp. 863-872 ◽  
Author(s):  
M Kielian ◽  
M R Klimjack ◽  
S Ghosh ◽  
W A Duffus
Keyword(s):  
Membrane Fusion ◽  
Cell Fusion ◽  
Semliki Forest Virus ◽  
Fusion Reaction ◽  
Infectious Clone ◽  
Low Ph ◽  
Spike Protein ◽  
Initial Reaction ◽  
Target Membrane ◽  
Cell Cell

Semliki Forest virus (SFV) infects cells by an acid-dependent membrane fusion reaction catalyzed by the virus spike protein, a complex containing E1 and E2 transmembrane subunits. E1 carries the putative virus fusion peptide, and mutations in this domain of the spike protein were previously shown to shift the pH threshold of cell-cell fusion (G91A), or block cell-cell fusion (G91D). We have used an SFV infectious clone to characterize virus particles containing these mutations. In keeping with the previous spike protein results, G91A virus showed limited secondary infection and an acid-shifted fusion threshold, while G91D virus was noninfectious and inactive in both cell-cell and virus-liposome fusion assays. During the low pH- induced SFV fusion reaction, the E1 subunit exposes new epitopes for monoclonal antibody (mAb) binding and forms an SDS-resistant homotrimer, the virus associates hydrophobically with the target membrane, and fusion of the virus and target membranes occurs. After low pH treatment, G91A spike proteins were shown to bind conformation-specific mAbs, associate with target liposome membranes, and form the E1 homotrimer. However, both G91A membrane association and homotrimer formation had an acid-shifted pH threshold and reduced efficiency compared to wt virus. In contrast, studies of the fusion-defective G91D mutant showed that the virus efficiently reacted with low pH as assayed by mAb binding and liposome association, but was essentially inactive in homotrimer formation. These results suggest that the G91D mutant is noninfectious due to a block in a late step in membrane fusion, separate from the initial reaction to low pH and interaction with the target membrane, and involving the lack of efficient formation of the E1 homotrimer.

Studies on cell fusion between Babesia rodhaini-infected mouse erythrocytes and baby hamster kidney cells

1975 ◽  
Vol 5 (4) ◽  
pp. 465-470 ◽  
Author(s):  
A.D. Irvin ◽  
D.A. Stagg ◽  
G.K. Kanhai ◽  
C.G.D. Brown ◽  
P.L. Omwoyo
Keyword(s):  
Infected Mouse ◽  
Cell Fusion ◽  
Kidney Cells ◽  
Baby Hamster Kidney ◽  
Baby Hamster Kidney Cells

Turbomolecular Pumped Electron Microscopy of Rubella Virus (In BHK Celis)

1968 ◽  
Vol 26 ◽  
pp. 204-205
Author(s):  
A. B. Taylor ◽  
G. C. Cole ◽  
M. A. Holcomb ◽  
C. A. Baechler
Keyword(s):  
Electron Microscopy ◽  
Rubella Virus ◽  
Phosphate Buffer ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Basal Medium ◽  
Kidney Cells ◽  
Baby Hamster Kidney ◽  
Input Multiplicity ◽  
Baby Hamster Kidney Cells

An aliquot from a continuous fermenter culture of baby hamster kidney cells (BHK-21 Clone PD-4) (Wistar) maintained in Ca free Eagle's Basal Medium containing 2% Kaolin adsorbed fetal calf serum was planted in spinner flasks at 300,000 cells per ml, total volume 600 ml. After equilibration for one day at 35°C to insure that cells were in log phase, the culture was infected with the M-33-AGMK25 BHK-219 strain of rubella at an input multiplicity of about 6 TCID50 per cell. The virus was identified with specific rubella antiserum.Preliminary experiments had shown that such cultures would reach a peak or plateau HA titer of approximately 1:64, 24 hrs after inoculation and would continue to yield virus for 6 to 12 days. One hundred ml aliquot harvests were withdrawn daily and the culture was returned to volume with growth medium and incubation continued. The harvested cells were spun down rapidly at 2500 rpm per 15 mins., fixed in 3.7% gluteraldehyde in Ca free phosphate buffer saline, and post fixed in osmium tetraoxide. After dehydration, the cells were embedded in Epon 812 and cured approximately 20 hrs at 60°C.

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