scholarly journals Early and late HIV-1 membrane fusion events are impaired by sphinganine lipidated peptides that target the fusion site

2014 ◽  
Vol 461 (2) ◽  
pp. 213-222 ◽  
Author(s):  
Yoel A. Klug ◽  
Avraham Ashkenazi ◽  
Mathias Viard ◽  
Ziv Porat ◽  
Robert Blumenthal ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Biological Membranes ◽  
Protein Assembly ◽  
Fusion Site ◽  
Lipidated Peptides ◽  
Hiv 1

We show that sphinganine lipidated peptides affect membrane fusion, modulate the membrane and disrupt protein assembly. In addition the findings may aid in deciphering the function of DHSM in biological membranes.

scholarly journals Analysis of Human Immunodeficiency Virus Type 1 Gag Dimerization-Induced Assembly

2005 ◽  
Vol 79 (23) ◽  
pp. 14498-14506 ◽  
Author(s):  
Ayna Alfadhli ◽  
Tenzin Choesang Dhenub ◽  
Amelia Still ◽  
Eric Barklis
Keyword(s):  
Human Immunodeficiency Virus ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Protein Assembly ◽  
Particle Assembly ◽  
Gag Protein ◽  
Immunodeficiency Virus ◽  
Hiv 1 ◽  
Terminal Domains

ABSTRACT The nucleocapsid (NC) domains of retrovirus precursor Gag (PrGag) proteins play an essential role in virus assembly. Evidence suggests that NC binding to viral RNA promotes dimerization of PrGag capsid (CA) domains, which triggers assembly of CA N-terminal domains (NTDs) into hexamer rings that are interconnected by CA C-terminal domains. To examine the influence of dimerization on human immunodeficiency virus type 1 (HIV-1) Gag protein assembly in vitro, we analyzed the assembly properties of Gag proteins in which NC domains were replaced with cysteine residues that could be linked via chemical treatment. In accordance with the model that Gag protein pairing triggers assembly, we found that cysteine cross-linking or oxidation reagents induced the assembly of virus-like particles. However, efficient assembly also was observed to be temperature dependent or required the tethering of NTDs. Our results suggest a multistep pathway for HIV-1 Gag protein assembly. In the first step, Gag protein pairing through NC-RNA interactions or C-terminal cysteine linkage fosters dimerization. Next, a conformational change converts assembly-restricted dimers or small oligomers into assembly-competent ones. At the final stage, final particle assembly occurs, possibly through a set of larger intermediates.

scholarly journals HIV-1 inhibitory properties of eCD4-Igmim2 determined using an Env-mediated membrane fusion assay

PLoS ONE ◽  
2018 ◽  
Vol 13 (10) ◽  
pp. e0206365
Author(s):  
Edward Yang ◽  
Matthew R. Gardner ◽  
Amber S. Zhou ◽  
Michael Farzan ◽  
Ann M. Arvin ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Hiv 1

scholarly journals Why are SNAREpins rod-shaped?

2021 ◽  
Author(s):  
Jin Zeng ◽  
Zachary McDargh ◽  
Dong An ◽  
Ben O'Shaughnessy
Keyword(s):  
Membrane Fusion ◽  
Strong Support ◽  
Force Production ◽  
Snare Proteins ◽  
Coarse Grained ◽  
Aspect Ratios ◽  
Extended Contact ◽  
Fusion Site ◽  
Simple Body ◽  
Core Components

SNARE proteins are the core components of the cellular machineries that fuse membranes for neurotransmitter or hormone release and other fundamental processes. Fusion is accomplished when SNARE proteins hosted by apposing membranes form SNARE complexes called SNAREpins, but the mechanism of fusion remains unclear. Computational simulations of SNARE-mediated membrane fusion are challenging due to the millisecond timescales of physiological membrane fusion. Here we used ultra-coarse-grained (UCG) simulations to investigate the minimal requirements for a molecular intracellular fusogen, and to elucidate the mechanisms of SNARE-mediated fusion. We find fusion by simple body forces that push vesicles together is highly inefficient. Inter-vesicle fusogens with different aspect ratios can fuse vesicles only if they are rodlike, of sufficient length to clear the fusogens from the fusion site by entropic forces. Simulations with rod-shaped SNAREpin-like fusogens fused 50-nm vesicles on ms timescales, driven by entropic forces along a reproducible fusion pathway. SNARE-SNARE and SNARE-membrane entropic forces cleared the fusion site and pressed the vesicles into an extended contact zone (ECZ), drove stalk nucleation at the high curvature ECZ boundary, and expanded the stalk into a long-lived hemifusion diaphragm in which a simple pore completed fusion. Our results provide strong support for the entropic hypothesis of SNARE-mediated membrane fusion, and implicate the rodlike structure of the SNAREpin complex as a necessity for entropic force production and fusion.

scholarly journals Molecular mechanism of HIV-1 resistance to sifuvirtide, a clinical trial–approved membrane fusion inhibitor

2018 ◽  
Vol 293 (33) ◽  
pp. 12703-12718 ◽  
Author(s):  
Danwei Yu ◽  
Xiaohui Ding ◽  
Zixuan Liu ◽  
Xiyuan Wu ◽  
Yuanmei Zhu ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Membrane Fusion ◽  
Molecular Mechanism ◽  
Fusion Inhibitor ◽  
Hiv 1

scholarly journals Therapeutic Efficacy and Resistance Selection of a Lipopeptide Fusion Inhibitor in Simian Immunodeficiency Virus-Infected Rhesus Macaques

2020 ◽  
Vol 94 (15) ◽  
Author(s):  
Danwei Yu ◽  
Jing Xue ◽  
Huamian Wei ◽  
Zhe Cong ◽  
Ting Chen ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Therapeutic Efficacy ◽  
Rhesus Macaques ◽  
Heptad Repeat ◽  
Fusion Inhibitor ◽  
Resistance Mutations ◽  
Fusion Inhibitors ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT We recently reported a group of lipopeptide-based membrane fusion inhibitors with potent antiviral activities against human immunodeficiency virus type 1 (HIV-1), HIV-2, and simian immunodeficiency virus (SIV). In this study, the in vivo therapeutic efficacy of such a lipopeptide, LP-52, was evaluated in rhesus macaques chronically infected with pathogenic SIVmac239. In a pilot study with one monkey, monotherapy with low-dose LP-52 rapidly reduced the plasma viral loads to below the limit of detection and maintained viral suppression during three rounds of structurally interrupted treatment. The therapeutic efficacy of LP-52 was further verified in four infected monkeys; however, three out of the monkeys had viral rebounds under the LP-52 therapy. We next focused on characterizing SIV mutants responsible for the in vivo resistance. Sequence analyses revealed that a V562A or V562M mutation in the N-terminal heptad repeat (NHR) and a E657G mutation in the C-terminal heptad repeat (CHR) of SIV gp41 conferred high resistance to LP-52 and cross-resistance to the peptide drug T20 and two newly designed lipopeptides (LP-80 and LP-83). Moreover, we showed that the resistance mutations greatly reduced the stability of diverse fusion inhibitors with the NHR site, and V562A or V562M in combination with E657G could significantly impair the functionality of viral envelopes (Envs) to mediate SIVmac239 infection and decrease the thermostability of viral six-helical bundle (6-HB) core structure. In conclusion, the present data have not only facilitated the development of novel anti-HIV drugs that target the membrane fusion step, but also help our understanding of the mechanism of viral evolution to develop drug resistance. IMPORTANCE The anti-HIV peptide drug T20 (enfuvirtide) is the only membrane fusion inhibitor available for treatment of viral infection; however, it exhibits relatively weak antiviral activity, short half-life, and a low genetic barrier to inducing drug resistance. Design of lipopeptide-based fusion inhibitors with extremely potent and broad antiviral activities against divergent HIV-1, HIV-2, and SIV isolates have provided drug candidates for clinical development. Here, we have verified a high therapeutic efficacy for the lipopeptide LP-52 in SIVmac239-infected rhesus monkeys. The resistance mutations selected in vivo have also been characterized, providing insights into the mechanism of action of newly designed fusion inhibitors with a membrane-anchoring property. For the first time, the data show that HIV-1 and SIV can share a similar genetic pathway to develop resistance, and that a lipopeptide fusion inhibitor could have a same resistance profile as its template peptide.

scholarly journals P2X1 Selective Antagonists Block HIV-1 Infection through Inhibition of Envelope Conformation-Dependent Fusion

2019 ◽  
Vol 94 (6) ◽  
Author(s):  
Alexandra Y. Soare ◽  
Hagerah S. Malik ◽  
Natasha D. Durham ◽  
Tracey L. Freeman ◽  
Raymond Alvarez ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Chronic Inflammation ◽  
Neutralizing Antibody ◽  
Extracellular Nucleotides ◽  
Productive Infection ◽  
Variable Regions ◽  
Viral Membrane ◽  
P2x1 Receptor ◽  
Viral Membrane Fusion ◽  
Hiv 1

ABSTRACT Purinergic receptors are well-established modulators of inflammatory processes, primarily through detection of extracellular nucleotides that are released by dying or infected cells. Emerging literature has demonstrated that inhibition of these inflammatory receptors can block HIV-1 productive infection and HIV-1-associated inflammation. The specificity of receptor type and mechanism of interaction has not yet been determined. Here, we characterize the inhibitory activity of P2X1 receptor antagonists, NF279 and NF449, in cell lines, primary cells, and a variety of HIV-1 envelope (Env) clades. NF279 and NF449 blocked productive infection at the level of viral membrane fusion, with a range of inhibitory activities against different HIV-1 Env isolates. A mutant virus carrying a truncation deletion of the C-terminal tail of HIV-1 Env glycoprotein 41 (gp41) showed reduced sensitivity to P2X1 antagonists, indicating that the sensitivity of inhibition by these molecules may be modulated by Env conformation. In contrast, a P2X7 antagonist, A438079, had a limited effect on productive infection and fusion. NF279 and NF449 interfered with the ability of the gp120 variable regions 1 and 2 (V1V2)-targeted broadly neutralizing antibody PG9 to block productive infection, suggesting that these drugs may antagonize HIV-1 Env at gp120 V1V2 to block viral membrane fusion. Our observations indicate that P2X1 antagonism can inhibit HIV-1 replication at the level of viral membrane fusion through interaction with Env. Future studies will probe the nature of these compounds in inhibiting HIV-1 fusion and the development of small molecules to block HIV-1 entry via this mechanism. IMPORTANCE While effective treatment can lower the severe morbidity and mortality associated with HIV-1 infection, patients infected with HIV-1 suffer from significantly higher rates of noncommunicable comorbidities associated with chronic inflammation. Emerging literature suggests a key role for P2X1 receptors in mediating this chronic inflammation, but the mechanism is still unknown. Here, we demonstrate that HIV-1 infection is reduced by P2X1 receptor antagonism. This inhibition is mediated by interference with HIV-1 Env and can impact a variety of viral clades. These observations highlight the importance of P2X1 antagonists as potential novel therapeutics that could serve to block a variety of different viral clades with additional benefits for their anti-inflammatory properties.

scholarly journals An effective strategy for recapitulating N-terminal heptad repeat trimers in enveloped virus surface glycoproteins for therapeutic applications

2016 ◽  
Vol 7 (3) ◽  
pp. 2145-2150 ◽  
Author(s):  
Wenqing Lai ◽  
Chao Wang ◽  
Fei Yu ◽  
Lu Lu ◽  
Qian Wang ◽  
...  
Keyword(s):  
Fusion Protein ◽  
Membrane Fusion ◽  
Heptad Repeat ◽  
Effective Strategy ◽  
Virus Surface ◽  
Efficient Strategy ◽  
Therapeutic Applications ◽  
Enveloped Virus ◽  
Membrane Fusion Protein ◽  
Hiv 1

We report an efficient strategy to recapitulate NHR α-helical trimers in the HIV-1 membrane fusion protein as promising antiviral therapeutics.

Role of Glycosphingolipids in HIV-1 Entry: Requirement of Globotriosylceramide (Gb3) in CD4/CXCR4-dependent Fusion

1999 ◽  
Vol 19 (4) ◽  
pp. 317-325 ◽  
Author(s):  
Anu Puri ◽  
Peter Hug ◽  
Kristine Jernigan ◽  
Patrick Rose ◽  
Robert Blumenthal
Keyword(s):  
Structural Analysis ◽  
Cell Fusion ◽  
Envelope Glycoprotein ◽  
Human Erythrocyte ◽  
Head Group ◽  
Specific Interactions ◽  
Cd4 Cells ◽  
Fusion Site ◽  
Hiv 1

We have recently shown that addition of human erythrocyte glycosphingolipids (GSL) to non-human CD4+ or GSL-depleted human CD4+ cells rendered those cells susceptible to gp120-gp41-mediated cell fusion (Puri et al., BBRC, 1998). One GSL fraction (Fraction 3) isolated from human erythrocyte GSL mixture exhibited the highest recovery of fusion following incorporation into CD4+ non-human and GSL-depleted HeLa-CD4 cells (HeLa-CD4/GSL-). Structural analysis of Fraction 3 showed that this GSL had identical head group as the known GSL, Gal(α1→4)Gal(β1→4)Glc-Ceramide (Gb3) (Puri et al., PNAS, 1998). Here we report that presence of Gb3 in CD4+/CXCR4+ cells but not CD4+/CXCR4- cells allows fusion with HIV-1Lai-envelope glycoprotein expressing cells (TF228). Therefore, Gb3 functions in conjunction with HIV-1 co-receptor, CXCR4 to promote fusion. We propose that Gb3 functions by recruiting CD4 and/or CXCR4 at the fusion site through structurally specific interactions.

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