Complete amino acid sequence and glycosylation sites of glycoprotein gp71A of Friend murine leukemia virus.

ABSTRACT The surface proteins (SU) of murine type-C retroviruses have a central hypervariable domain devoid of cysteine and rich in proline. This 41-amino-acid region of Friend ecotropic murine leukemia virus SU was shown to be highly tolerant of insertions and deletions. Viruses in which either the N-terminal 30 amino acids or the C-terminal 22 amino acids of this region were replaced by the 7-amino-acid sequence ASAVAGA were fully infectious. Insertions of this 7-amino-acid sequence at the N terminus, center, and the C terminus of the hypervariable domain had little effect on envelope protein (Env) function, while this insertion at a position 10 amino acids following the N terminus partially destabilized the association between the SU and transmembrane subunits of Env. Large, complex domains (either a 252-amino-acid single-chain antibody binding domain [scFv] or a 96-amino-acid V1/V2 domain of HIV-1 SU containing eight N-linked glycosylation sites and two disulfides) did not interfere with Env function when inserted in the center or C-terminal portions of the hypervariable domain. The scFv domain inserted into the C-terminal region of the hypervariable domain was shown to mediate binding of antigen to viral particles, demonstrating that it folded into the active conformation and was displayed on the surface of the virion. Both positive and negative enrichment of virions expressing the V1/V2 sequence were achieved by using a monoclonal antibody specific for a conformational epitope presented by the inserted sequence. These results indicated that the hypervariable domain of Friend ecotropic SU does not contain any specific sequence or structure that is essential for Env function and demonstrated that insertions into this domain can be used to extend particle display methodologies to complex protein domains that require expression in eukaryotic cells for glycosylation and proper folding.

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Amino Acid Substitutions in the CA Protein of Moloney Murine Leukemia Virus That Block Early Events in Infection

Virology ◽

10.1006/viro.1996.0431 ◽

1996 ◽

Vol 222 (2) ◽

pp. 339-351 ◽

Cited By ~ 41

Author(s):

Kimona Alin ◽

Stephen P. Goff

Keyword(s):

Amino Acid ◽

Murine Leukemia Virus ◽

Leukemia Virus ◽

Moloney Murine Leukemia Virus ◽

Amino Acid Substitutions ◽

Murine Leukemia ◽

Ca Protein

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Amino acid substitutions away from the RNase H catalytic site increase the thermal stability of Moloney murine leukemia virus reverse transcriptase through RNase H inactivation

Biochemical and Biophysical Research Communications ◽

10.1016/j.bbrc.2014.10.044 ◽

2014 ◽

Vol 454 (2) ◽

pp. 269-274 ◽

Cited By ~ 2

Author(s):

Atsushi Konishi ◽

Tetsuro Hisayoshi ◽

Kanta Yokokawa ◽

Verónica Barrioluengo ◽

Luis Menéndez-Arias ◽

...

Keyword(s):

Thermal Stability ◽

Amino Acid ◽

Reverse Transcriptase ◽

Murine Leukemia Virus ◽

Leukemia Virus ◽

Rnase H ◽

Moloney Murine Leukemia Virus ◽

Amino Acid Substitutions ◽

Thermal Stability Of ◽

Murine Leukemia

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Oligosaccharides at individual glycosylation sites in glycoprotein 71 of Friend murine leukemia virus

European Journal of Biochemistry ◽

10.1111/j.1432-1033.1990.tb15282.x ◽

1990 ◽

Vol 187 (1) ◽

pp. 105-110

Author(s):

Rudolf GEYER ◽

Janusz DABROWSKI ◽

Ursula DABROWSKI ◽

Dietmar LINDER ◽

Michael SCHLUTER ◽

...

Keyword(s):

Murine Leukemia Virus ◽

Leukemia Virus ◽

Glycosylation Sites ◽

Murine Leukemia

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Definition of a 14-Amino-Acid Peptide Essential for the Interaction between the Murine Leukemia Virus Amphotropic Envelope Glycoprotein and Its Receptor

Journal of Virology ◽

10.1128/jvi.72.1.428-435.1998 ◽

1998 ◽

Vol 72 (1) ◽

pp. 428-435 ◽

Cited By ~ 23

Author(s):

Jean Luc Battini ◽

Olivier Danos ◽

Jean Michel Heard

Keyword(s):

Amino Acid ◽

Receptor Binding ◽

Envelope Glycoprotein ◽

Murine Leukemia Virus ◽

Leukemia Virus ◽

Target Cells ◽

Structural Constraints ◽

Binding Interaction ◽

Receptor Recognition ◽

Murine Leukemia

ABSTRACT Hydrophilic loops in the receptor binding domain of the amphotropic murine leukemia virus (MLV) envelope glycoprotein (SU) are predicted and may participate in SU-receptor interactions. We have replaced five segments of 6 to 15 amino acids located in each of these regions with an 11-amino-acid tag from the vesicular stomatitis virus glycoprotein (VSV-G). Substitution was compatible with envelope processing, transport, and incorporation into virions. However, three substitution mutants showed a temperature-dependent phenotype, suggesting structural unstability. Accessibility of the tagging epitope for a monoclonal anti-VSV-G antibody was greater in oligomeric than in monomeric SUs when insertion was done in VRA, a domain essential for receptor recognition. In contrast, accessibility was independent of structural constraints when insertion was done in VRB, a domain playing an accessory role in receptor binding. Interaction with the amphotropic receptor was investigated by interference assay and study of binding and infection of target cells with MLV particles coated with the substituted envelopes. Envelope-receptor interaction was abolished when substitution was performed in a potential loop-forming segment located at the N-terminal half of VRA. Although interaction was affected to variable extents, depending on the substituted segment, other mutants conserved the ability to interact with the amphotropic receptor. These experiments indicate the 14-amino-acid segment between positions 50 and 64 of SU as an essential determinant of amphotropic-receptor recognition. They also show that a foreign linear epitope can be tolerated in several locations of the amphotropic SU receptor binding site, and this result has implications for the design of targeted retroviral vectors.

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A Single Amino Acid Change in the Murine Leukemia Virus Capsid Gene Responsible for theFv1nr Phenotype

Journal of Virology ◽

10.1128/jvi.74.11.5385-5387.2000 ◽

2000 ◽

Vol 74 (11) ◽

pp. 5385-5387 ◽

Cited By ~ 22

Author(s):

Yong Tae Jung ◽

Christine A. Kozak

Keyword(s):

Amino Acid ◽

Murine Leukemia Virus ◽

Amino Acid Change ◽

Leukemia Virus ◽

Single Amino Acid ◽

Amino Acid Difference ◽

Site Specific ◽

Single Amino Acid Change ◽

Leukemia Viruses ◽

Murine Leukemia

ABSTRACT The nr allele at the mouse Fv1 restriction locus governs resistance to B-tropic and some N-tropic murine leukemia viruses (MLVs). Sequence analysis and site-specific mutagenesis of N-tropic MLVs identified a single amino acid difference responsible for this restriction that is distinct from the site that governs N or B tropism. Viruses with other substitutions at this site were evaluated for altered replication patterns.

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Identification of the Regions of Fv1 Necessary for Murine Leukemia Virus Restriction

Journal of Virology ◽

10.1128/jvi.75.11.5182-5188.2001 ◽

2001 ◽

Vol 75 (11) ◽

pp. 5182-5188 ◽

Cited By ~ 50

Author(s):

Kate N. Bishop ◽

Michael Bock ◽

Greg Towers ◽

Jonathan P. Stoye

Keyword(s):

Amino Acid ◽

Virus Replication ◽

Murine Leukemia Virus ◽

Leukemia Virus ◽

Single Amino Acid ◽

Viral Capsid ◽

Amino Acid Substitutions ◽

Terminal Portion ◽

Major Homology Region ◽

Murine Leukemia

ABSTRACT The Fv1 gene restricts murine leukemia virus replication via an interaction with the viral capsid protein. To study this interaction, a number of mutations, including a series of N-terminal and C-terminal deletions, internal deletions, and a number of single-amino-acid substitutions, were introduced into the n and b alleles of the Fv1 gene and the effects of these changes on virus restriction were measured. A significant fraction of the Fv1 protein was not required for restriction; however, retention of an intact major homology region as well as of domains toward the N and C termini was essential. Binding specificity appeared to be a combinatorial property of a number of residues within the C-terminal portion of Fv1.

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Generation of Novel Syncytium-Inducing and Host Range Variants of Ecotropic Moloney Murine Leukemia Virus in Mus spicilegus

Journal of Virology ◽

10.1128/jvi.77.9.5065-5072.2003 ◽

2003 ◽

Vol 77 (9) ◽

pp. 5065-5072 ◽

Cited By ~ 9

Author(s):

Yong Tae Jung ◽

Christine A. Kozak

Keyword(s):

Amino Acid ◽

Host Range ◽

Murine Leukemia Virus ◽

Leukemia Virus ◽

Wild Mouse ◽

Cell Surface Receptor ◽

Single Amino Acid ◽

Mus Spicilegus ◽

Ecotropic Virus ◽

Murine Leukemia

ABSTRACT Mus spicilegus is an Eastern European wild mouse species that has previously been reported to harbor an unusual infectious ecotropic murine leukemia virus (MLV) and proviral envelope genes of a novel MLV subgroup. In the present study, M. spicilegus neonates were inoculated with Moloney ecotropic MLV (MoMLV). All 17 inoculated mice produced infectious ecotropic virus after 8 to 14 weeks, and two unusual phenotypes distinguished the isolates from MoMLV. First, most of the M. spicilegus isolates grew to equal titers on M. dunni and SC-1 cells, although MoMLV does not efficiently infect M. dunni cells. The deduced amino acid sequence of a representative clone differed from MoMLV by insertion of two serine residues within the VRA of SUenv. Modification of a molecular clone of MoMLV by the addition of these serines produced a virus that grows to high titer in M. dunni cells, establishing a role for these two serine residues in host range. A second unusual phenotype was found in only one of the M. spicilegus isolates, Spl574. Spl574 produces large syncytia of multinucleated giant cells in M. dunni cells, but its replication is restricted in other mouse cell lines. Sequencing and mutagenesis demonstrated that syncytium formation could be attributed to a single amino acid substitution within VRA, S82F. Thus, viruses with altered growth properties are selected during growth in M. spicilegus. The mutations associated with the host range and syncytium-inducing variants map to a key region of VRA known to govern interactions with the cell surface receptor, suggesting that the associated phenotypes may result from altered interactions with the unusual ecotropic virus mCAT1 receptor carried by M. dunni.

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