Functional analysis of the cytoplasmic tail of Moloney murine leukemia virus envelope protein.

1997 ◽  
Vol 71 (5) ◽  
pp. 3613-3619 ◽  
Author(s):  
M M Januszeski ◽  
P M Cannon ◽  
D Chen ◽  
Y Rozenberg ◽  
W F Anderson
Keyword(s):  
Functional Analysis ◽  
Envelope Protein ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Cytoplasmic Tail ◽  
Moloney Murine Leukemia Virus ◽  
Virus Envelope ◽  
Virus Envelope Protein ◽  
Murine Leukemia

scholarly journals Cytoplasmic Tail of Moloney Murine Leukemia Virus Envelope Protein Influences the Conformation of the Extracellular Domain: Implications for Mechanism of Action of the R Peptide

2003 ◽  
Vol 77 (2) ◽  
pp. 1281-1291 ◽  
Author(s):  
Hector C. Aguilar ◽  
W. French Anderson ◽  
Paula M. Cannon
Keyword(s):  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Cytoplasmic Tail ◽  
Moloney Murine Leukemia Virus ◽  
Virus Envelope ◽  
Peptide Cleavage ◽  
Virus Envelope Protein ◽  
Env Protein ◽  
Membrane Spanning ◽  
Murine Leukemia

ABSTRACT The envelope (Env) protein of Moloney murine leukemia virus (MoMuLV) is a homotrimeric complex whose monomers consist of linked surface (SU) and transmembrane (TM) proteins cleaved from a precursor protein by a cellular protease. In addition, a significant fraction of virion-associated TM is further processed by the viral protease to remove the C-terminal 16 amino acids of the cytoplasmic domain, the R peptide. This cleavage greatly enhances the fusogenicity of the protein and is necessary for the formation of a fully functional Env protein complex. We have previously proposed that R peptide cleavage enhances fusogenicity by altering the conformation of the ectodomain of the protein (Y. Zhao et al., J. Virol. 72:5392-5398, 1998). Using a series of truncation and point mutants of MoMuLV Env, we now provide direct biochemical and immunological evidence that the cytoplasmic tail and the membrane-spanning region of Env can influence the overall structure of the ectodomain of the protein and alter the strength of the SU-TM interaction. The R-peptide-truncated form of the protein, in particular, exhibits a markedly different conformation than the full-length protein.

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.

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