scholarly journals Cell Signaling through the Protein Kinases cAMP-dependent Protein Kinase, Protein Kinase Cϵ, and RAF-1 Regulates Amphotropic Murine Leukemia Virus Envelope Protein-induced Syncytium Formation

2005 ◽  
Vol 280 (17) ◽  
pp. 16772-16783 ◽  
Author(s):  
Wei Wang ◽  
Zsolt Jobbagy ◽  
Terry H. Bird ◽  
Maribeth V. Eiden ◽  
Wayne B. Anderson
Keyword(s):  
Protein Kinase ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Syncytium Formation ◽  
Virus Envelope ◽  
Dependent Protein Kinase ◽  
Amphotropic Murine Leukemia Virus ◽  
Dependent Protein ◽  
Virus Envelope Protein ◽  
Murine Leukemia

Functional dissection of the Moloney murine leukemia virus envelope protein gp70.

1997 ◽  
Vol 71 (3) ◽  
pp. 2092-2099 ◽  
Author(s):  
Y Bae ◽  
S M Kingsman ◽  
A J Kingsman
Keyword(s):  
Envelope Protein ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Moloney Murine Leukemia Virus ◽  
Virus Envelope ◽  
Virus Envelope Protein ◽  
Murine Leukemia

scholarly journals Sequential activation of the three protomers in the Moloney murine leukemia virus Env

2017 ◽  
Vol 114 (10) ◽  
pp. 2723-2728 ◽  
Author(s):  
Mathilda Sjöberg ◽  
Robin Löving ◽  
Birgitta Lindqvist ◽  
Henrik Garoff
Keyword(s):  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Moloney Murine Leukemia Virus ◽  
Virus Envelope ◽  
Sequential Activation ◽  
Virus Envelope Protein ◽  
Membrane Fusion Proteins ◽  
Viral Membrane Fusion ◽  
Murine Leukemia

Viral membrane fusion proteins of class I are trimers in which the protomeric unit is a complex of a surface subunit (SU) and a fusion active transmembrane subunit (TM). Here we have studied how the protomeric units of Moloney murine leukemia virus envelope protein (Env) are activated in relation to each other, sequentially or simultaneously. We followed the isomerization of the SU-TM disulfide and subsequent SU release from Env with biochemical methods and found that this early activation step occurred sequentially in the three protomers, generating two asymmetric oligomer intermediates according to the scheme (SU-TM)3→ (SU-TM)2TM → (SU-TM)TM2→ TM3. This was the case both when activation was triggered in vitro by depleting stabilizing Ca2+from solubilized Env and when viral Env was receptor triggered on rat XC cells. In the latter case, the activation reaction was too fast for direct observation of the intermediates, but they could be caught by alkylation of the isomerization active thiol.

scholarly journals Moloney Murine Leukemia Virus Envelope Protein Subunits, gp70 and Pr15E, Form a Stable Disulfide-Linked Complex

1998 ◽  
Vol 72 (8) ◽  
pp. 6537-6545 ◽  
Author(s):  
Dirk-Jan E. Opstelten ◽  
Michael Wallin ◽  
Henrik Garoff
Keyword(s):  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Alkylating Agents ◽  
Moloney Murine Leukemia Virus ◽  
Virus Envelope ◽  
Disulfide Linkage ◽  
Virus Envelope Protein ◽  
Biochemical Analyses ◽  
Murine Leukemia

ABSTRACT The nature and stability of the interactions between the gp70 and Pr15E/p15E molecules of murine leukemia virus (MLV) have been disputed extensively. To resolve this controversy, we have performed quantitative biochemical analyses on gp70-Pr15E complexes formed after independent expression of the amphotropic and ecotropic Moloney MLVenv genes in BHK-21 cells. We found that all cell-associated gp70 molecules are disulfide linked to Pr15E whereas only a small amount of free gp70 is released by the cells. The complexes were resistant to treatment with reducing agents in vivo, indicating that the presence and stability of the disulfide interaction between gp70 and Pr15E are not dependent on the cellular redox state. However, disulfide-bonded Env complexes were disrupted in lysates of nonalkylated cells in a time-, temperature-, and pH-dependent fashion. Disruption seemed not to be caused by a cellular factor but is probably due to a thiol-disulfide exchange reaction occurring within the Env complex after solubilization. The possibility that alkylating agents induce the formation of the intersubunit disulfide linkage was excluded by showing that disulfide-linked gp70-Pr15E complexes exist in freshly made lysates of nonalkylated cells and that disruption of the complexes can be prevented by lowering the pH. Together, these data establish that gp70 and Pr15E form a stable disulfide-linked complex in vivo.

scholarly journals Immunoprotective Determinants in Friend Murine Leukemia Virus Envelope Protein

Virology ◽  
1998 ◽  
Vol 248 (1) ◽  
pp. 66-73 ◽  
Author(s):  
Kim J. Hasenkrug ◽  
Diane M. Brooks ◽  
Michael N. Robertson ◽  
R.V. Srinivas ◽  
Bruce Chesebro
Keyword(s):  
Envelope Protein ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Virus Envelope ◽  
Virus Envelope Protein ◽  
Murine Leukemia

Small synthetic ligands for the enrichment of viral particles pseudotyped with amphotropic murine leukemia virus envelope

2016 ◽  
Vol 1438 ◽  
pp. 160-170 ◽  
Author(s):  
Cláudia S.M. Fernandes ◽  
Rute Castro ◽  
Ana Sofia Coroadinha ◽  
A. Cecília A. Roque
Keyword(s):  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Virus Envelope ◽  
Amphotropic Murine Leukemia Virus ◽  
Viral Particles ◽  
Murine Leukemia

scholarly journals A Hydrophobic Patch in Ecotropic Murine Leukemia Virus Envelope Protein Is the Putative Binding Site for a Critical Tyrosine Residue on the Cellular Receptor

1999 ◽  
Vol 73 (12) ◽  
pp. 10164-10172 ◽  
Author(s):  
Tatiana Zavorotinskaya ◽  
Lorraine M. Albritton
Keyword(s):  
Envelope Protein ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Wild Type Virus ◽  
Wild Type ◽  
Virus Binding ◽  
Virus Envelope ◽  
Virus Envelope Protein ◽  
Putative Binding Site ◽  
Murine Leukemia

ABSTRACT In the receptor for ecotropic murine leukemia viruses, tyrosine 235 contributes a critical hydrophobic side chain to the virus-receptor interaction (14). Here we report that tryptophan 142 in ecotropic Moloney murine leukemia virus envelope protein is essential to virus binding and infection. Replacement of tryptophan 142 by alanine or serine resulted in misfolding. However, replacement by methionine (W142M) allowed correct folding of the majority of glycoprotein molecules. W142M virus showed a marked reduction in virus binding and was almost noninfectious, suggesting that tryptophan 142 is involved in receptor binding. In contrast, W142Y virus containing a replacement of tryptophan 142 with an aromatic residue (tyrosine) was as efficient as wild-type virus in infection and binding of cells expressing the wild-type receptor. However, W142Y virus was 100-fold less efficient than wild-type virus in infection of cells expressing a mutant receptor containing tryptophan instead of the critical tyrosine. These results strongly support tryptophan 142 being an essential residue on the virus envelope protein that interacts directly with the critical hydrophobic residue at position 235 of the ecotropic receptor. Tryptophan 142 forms one side of a shallow hydrophobic pocket on the surface of the envelope protein, suggesting that it might comprise the complete putative binding site for tyrosine 235. We discuss the implications of our findings with respect to two models of the envelope protein trimer. Interestingly, both models place tryptophan 142 at the interface between adjacent subunits of the trimer.

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