Previous Article | Next Article 
J Virol, April 1998, p. 3259-3267, Vol. 72, No. 4
0022-538X/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.
Mutational Analysis of the Candidate Internal
Fusion Peptide of the Avian Leukosis and Sarcoma Virus Subgroup A
Envelope Glycoprotein
Lorraine D.
Hernandez1,2 and
Judith M.
White2,*
Department of Biochemistry, University of
California, San Francisco, California 94143,1
and
Department of Cell Biology, University of Virginia Health
Sciences Center, Charlottesville, Virginia 229082
Received 8 July 1997/Accepted 23 December 1997
The transmembrane subunit (TM) of the avian leukosis and sarcoma
virus (ALSV) envelope glycoprotein (Env) contains a stretch of
conserved hydrophobic amino acids internal to its amino terminus (residues 21 to 42). By analogy with similar sequences in other viral
envelope glycoproteins, this region has been proposed to be a fusion
peptide. We investigated the role of this region by changing each of
three hydrophobic residues (Ile-21, Val-30, and Ile-39) to glutamatic
acid and lysine in the ALSV subgroup A Env. Like wild-type (wt) Env,
all six mutant Env proteins were proteolytically processed,
oligomerized, and expressed at the cell surface in a form that bound
Tva, the ALSV subgroup A receptor. Like wt Env, Ile21Glu, Ile21Lys,
Val30Glu, and Val30Lys changed conformation upon binding Tva, as
assayed by sensitivity to thermolysin. Ile39Glu and Ile39Lys were
cleaved by thermolysin in both the absence and presence of Tva.
Although incorporated into virus particles at approximately equal
levels, all mutant Envs were compromised in their ability to support
infection. The mutants at residues 21 and 30 showed levels of infection
2 to 3 orders of magnitude lower than that of wt Env. The mutants at
residue 39 were noninfectious. Furthermore, none of the mutants
displayed activity in a cell-cell fusion assay. Our results support the
contention that residues 21 to 42 of ALSV subgroup A Env constitute its
fusion peptide.
*
Corresponding author. Mailing address: Department of
Cell Biology, University of Virginia Health Sciences Center, Box 439, Charlottesville, VA 22908. Phone: (804) 924-2593. Fax: (804) 982-3912. E-mail: jw7g{at}virginia.edu.
This article has been cited by other articles:
-
Amberg, S. M., Netter, R. C., Simmons, G., Bates, P.
(2006). Expanded Tropism and Altered Activation of a Retroviral Glycoprotein Resistant to an Entry Inhibitor Peptide. J. Virol.
80: 353-359
[Abstract]
[Full Text]
-
Sainz, B. Jr., Rausch, J. M., Gallaher, W. R., Garry, R. F., Wimley, W. C.
(2005). Identification and Characterization of the Putative Fusion Peptide of the Severe Acute Respiratory Syndrome-Associated Coronavirus Spike Protein. J. Virol.
79: 7195-7206
[Abstract]
[Full Text]
-
Matsuyama, S., Delos, S. E., White, J. M.
(2004). Sequential Roles of Receptor Binding and Low pH in Forming Prehairpin and Hairpin Conformations of a Retroviral Envelope Glycoprotein. J. Virol.
78: 8201-8209
[Abstract]
[Full Text]
-
Melikyan, G. B., Barnard, R. J. O., Markosyan, R. M., Young, J. A. T., Cohen, F. S.
(2004). Low pH Is Required for Avian Sarcoma and Leukosis Virus Env-Induced Hemifusion and Fusion Pore Formation but Not for Pore Growth. J. Virol.
78: 3753-3762
[Abstract]
[Full Text]
-
Earp, L. J., Delos, S. E., Netter, R. C., Bates, P., White, J. M.
(2003). The Avian Retrovirus Avian Sarcoma/Leukosis Virus Subtype A Reaches the Lipid Mixing Stage of Fusion at Neutral pH. J. Virol.
77: 3058-3066
[Abstract]
[Full Text]
-
Ochsenbauer-Jambor, C., Delos, S. E., Accavitti, M. A., White, J. M., Hunter, E.
(2002). Novel Monoclonal Antibody Directed at the Receptor Binding Site on the Avian Sarcoma and Leukosis Virus Env Complex. J. Virol.
76: 7518-7527
[Abstract]
[Full Text]
-
Stiasny, K., Allison, S. L., Schalich, J., Heinz, F. X.
(2002). Membrane Interactions of the Tick-Borne Encephalitis Virus Fusion Protein E at Low pH. J. Virol.
76: 3784-3790
[Abstract]
[Full Text]
-
Taylor, G. M., Gao, Y., Sanders, D. A.
(2001). Fv-4: Identification of the Defect in Env and the Mechanism of Resistance to Ecotropic Murine Leukemia Virus. J. Virol.
75: 11244-11248
[Abstract]
[Full Text]
-
Stiasny, K., Allison, S. L., Mandl, C. W., Heinz, F. X.
(2001). Role of Metastability and Acidic pH in Membrane Fusion by Tick-Borne Encephalitis Virus. J. Virol.
75: 7392-7398
[Abstract]
[Full Text]
-
Allison, S. L., Schalich, J., Stiasny, K., Mandl, C. W., Heinz, F. X.
(2001). Mutational Evidence for an Internal Fusion Peptide in Flavivirus Envelope Protein E. J. Virol.
75: 4268-4275
[Abstract]
[Full Text]
-
Taguchi, F., Shimazaki, Y. K.
(2000). Functional analysis of an epitope in the S2 subunit of the murine coronavirus spike protein: involvement in fusion activity. J. Gen. Virol.
81: 2867-2871
[Abstract]
[Full Text]
-
Delos, S. E., White, J. M.
(2000). Critical Role for the Cysteines Flanking the Internal Fusion Peptide of Avian Sarcoma/Leukosis Virus Envelope Glycoprotein. J. Virol.
74: 9738-9741
[Abstract]
[Full Text]
-
Balliet, J. W., Gendron, K., Bates, P.
(2000). Mutational Analysis of the Subgroup A Avian Sarcoma and Leukosis Virus Putative Fusion Peptide Domain. J. Virol.
74: 3731-3739
[Abstract]
[Full Text]
-
Delos, S. E., Gilbert, J. M., White, J. M.
(2000). The Central Proline of an Internal Viral Fusion Peptide Serves Two Important Roles. J. Virol.
74: 1686-1693
[Abstract]
[Full Text]
-
Ito, H., Watanabe, S., Sanchez, A., Whitt, M. A., Kawaoka, Y.
(1999). Mutational Analysis of the Putative Fusion Domain of Ebola Virus Glycoprotein. J. Virol.
73: 8907-8912
[Abstract]
[Full Text]
-
Qiao, H., Armstrong, R. T., Melikyan, G. B., Cohen, F. S., White, J. M.
(1999). A Specific Point Mutant at Position 1 of the Influenza Hemagglutinin Fusion Peptide Displays a Hemifusion Phenotype. Mol. Biol. Cell
10: 2759-2769
[Abstract]
[Full Text]