The Role of the Membrane-spanning Domain Sequence in Glycoprotein-mediated Membrane Fusion

Taylor, Gwen M.; Sanders, D.A.R.

doi:10.1091/mbc.10.9.2803

Cited by 50 publications

(42 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, the GPI-linked ectodomain construct, GLA15E, was always observed to be nonfusogenic, despite high levels of CSE in the transfected 293T cells. These results confirm that the membrane-spanning region of TM is essential for Env-mediated fusion (52,65). The ability of retroviral vectors carrying the various Env proteins to transduce NIH 3T3 cells was also measured, and our results are in good agreement with previous reports (29,52,53).…”

Section: Properties Of Momulv Env Proteinssupporting

confidence: 92%

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

Aguilar

Anderson

Cannon

2003

J Virol

View full text Add to dashboard Cite

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-peptidetruncated form of the protein, in particular, exhibits a markedly different conformation than the full-length protein.Retroviral envelope (Env) glycoproteins are expressed on the surface of infected cells and are incorporated into the viral lipid envelope during budding of a virion from a cell. Following binding to a specific cell surface receptor, Env promotes fusion between the viral and host cell membranes and thereby initiates a new infection. For the murine leukemia viruses (MuLVs), Env is initially translated as a precursor protein, Pr85, which oligomerizes in the endoplasmic reticulum, probably as a homotrimer (17). This precursor is cleaved by a cellular protease into two subunits, the surface (SU) protein gp70 and the transmembrane (TM) protein p15E, which remain associated in a labile interaction which may include a disulfide bond (48,51).MuLV Env also undergoes a second cleavage event in the cytoplasmic tail of TM that is essential for protein function. The C-terminal 16 amino acids of the cytoplasmic tail, the R peptide, is removed from a subset of the virion TM proteins by the viral protease (22,27,60). This results in an Env protein that is inherently more fusogenic than the full-length protein, causing, for example, cell-cell fusion to occur when it is expressed in NIH 3T3 cells (29,53,54). It has been suggested that the virus has adopted this strategy of regulating Env fusogenicity in order to limit the expression of a potentially cytotoxic molecule on the cell surface (53, 54). Similar processing of Env cytoplasmic tails has been observed in the MasonPfizer monkey virus (M-PMV), the gibbon ape leukemia virus (GaLV), and the equine infectious anemia virus (4, 7, 56); in addition, truncated M-PMV and GaLV Env proteins are more fusogenic than their full-length counterparts (3, 7). Truncations of the long cytoplasmic domains of lentiviral Env proteins occur under certain culture conditions (5,31,32,59), and an increase in Env fusogenicity has been reported for...

show abstract

Section: Properties Of Momulv Env Proteinssupporting

confidence: 92%

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

Aguilar

Anderson

Cannon

2003

J Virol

View full text Add to dashboard Cite

show abstract

“…Other studies support that fusion is impaired by replacing the gp41 TM with the TM domain from glycoporin A, vesicular stomatitis virus (VSV) G (155), and, more recently, the TM domain from influenza virus hemagglutinin (HA) (128). This is further supported by observations that TM plays a role in fusion in other viral proteins (128,224).…”

Section: The Tm Regionmentioning

confidence: 87%

The Membrane-Proximal External Region of the Human Immunodeficiency Virus Type 1 Envelope: Dominant Site of Antibody Neutralization and Target for Vaccine Design

Montero¹,

Houten

Wang³

et al. 2008

Microbiol Mol Biol Rev

234

194

View full text Add to dashboard Cite

SUMMARY Enormous efforts have been made to produce a protective vaccine against human immunodeficiency virus type 1; there has been little success. However, the identification of broadly neutralizing antibodies against epitopes on the highly conserved membrane-proximal external region (MPER) of the gp41 envelope protein has delineated this region as an attractive vaccine target. Furthermore, emerging structural information on the MPER has provided vaccine designers with new insights for building relevant immunogens. This review describes the current state of the field regarding (i) the structure and function of the gp41 MPER; (ii) the structure and binding mechanisms of the broadly neutralizing antibodies 2F5, 4E10, and Z13; and (iii) the development of an MPER-targeting vaccine. In addition, emerging approaches to vaccine design are presented.

show abstract

“…This is an apparent contradiction to the effects of TMS point mutations as discussed above. The data may be reconciled, however, if one assumes that the structural feature(s) rendering a TMS compatible with fusion protein function are shared by certain unrelated TMSs which would be inactive in their normal contexts (2,14).…”

Section: Fig 3 Properties Of Liposome Fusion Induced By Wt Tms-peptmentioning

confidence: 99%

“…In another study, shortening the HA TMS reduced its ability to support the hemifusion to fusion transition whereas point mutations were without effect (12). Furthermore, the function of other fusion proteins derived from the human immunodeficiency virus type 1 envelope glycoprotein (13) or the Moloney murine leukemia virus (14) was compromized by mutations within the TMSs.…”

mentioning

confidence: 99%

Peptide Mimics of the Vesicular Stomatitis Virus G-protein Transmembrane Segment Drive Membrane Fusion in Vitro

Langosch¹,

Brosig²,

Pipkorn³

2001

Journal of Biological Chemistry

View full text Add to dashboard Cite

The efficiency of cell-cell fusion mediated by heterologously expressed vesicular stomatitis virus G-protein has previously been shown to be affected by mutating its transmembrane segment. Here, we show that a synthetic peptide modeled after this transmembrane segment drives liposome-liposome fusion. Addition of millimolar Ca 2؉ concentrations strongly potentiated the effect of the peptides suggesting that Ca 2؉ -mediated liposome aggregation supports the activity of the peptide. Peptide-driven fusion was suppressed by lysolipid, an established inhibitor of natural membrane fusion, and involved inner and outer leaflets of the liposomal bilayer. Thus, transmembrane segment peptide-driven liposome fusion exhibits important hallmarks characteristic of natural membrane fusion. Importantly, the mutations previously shown to attenuate the function of full-length G-protein in cell-cell fusion also attenuated the fusogenicity of the peptide, albeit in a less pronounced fashion. Therefore, the function of the peptide mimic is dependent on its primary structure, similar to full-length G-protein. Together, our data suggest that the G-protein transmembrane segment is an autonomous functional domain. We propose that it acts at a late step in membrane fusion elicited by vesicular stomatitis virus.

show abstract

The Role of the Membrane-spanning Domain Sequence in Glycoprotein-mediated Membrane Fusion

Cited by 50 publications

References 60 publications

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

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

The Membrane-Proximal External Region of the Human Immunodeficiency Virus Type 1 Envelope: Dominant Site of Antibody Neutralization and Target for Vaccine Design

Peptide Mimics of the Vesicular Stomatitis Virus G-protein Transmembrane Segment Drive Membrane Fusion in Vitro

Contact Info

Product

Resources

About