The Signal Peptide of the Ebolavirus Glycoprotein Influences Interaction with the Cellular Lectins DC-SIGN and DC-SIGNR

Marzi, Andrea; Akhavan, Armin; Simmons, Graham; Gramberg, Thomas; Hofmann, Heike; Bates, Paul; Lingappa, Vishwanath R.; Pöhlmann, Stefan

doi:10.1128/jvi.02545-05

Cited by 53 publications

(45 citation statements)

References 69 publications

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“…One of these—R29K (variant B7) —was located in the signal peptide, mutations in which have previously been associated with changes in glycosylation and the enhancement of infectivity (Marzi et al., 2006). Similarly, mutations that resulted in the loss of conserved N-glycosylation sites (T206M in variant B12 and T230A in variant B13, affecting N-glycosylation on N204 and N228) strongly increased GP entry into human cells.…”

Section: Discussionmentioning

confidence: 99%

Human Adaptation of Ebola Virus during the West African Outbreak

Urbanowicz

McClure

Sakuntabhai

et al. 2016

Cell

192

188

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SummaryThe 2013–2016 outbreak of Ebola virus (EBOV) in West Africa was the largest recorded. It began following the cross-species transmission of EBOV from an animal reservoir, most likely bats, into humans, with phylogenetic analysis revealing the co-circulation of several viral lineages. We hypothesized that this prolonged human circulation led to genomic changes that increased viral transmissibility in humans. We generated a synthetic glycoprotein (GP) construct based on the earliest reported isolate and introduced amino acid substitutions that defined viral lineages. Mutant GPs were used to generate a panel of pseudoviruses, which were used to infect different human and bat cell lines. These data revealed that specific amino acid substitutions in the EBOV GP have increased tropism for human cells, while reducing tropism for bat cells. Such increased infectivity may have enhanced the ability of EBOV to transmit among humans and contributed to the wide geographic distribution of some viral lineages.

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Section: Discussionmentioning

confidence: 99%

Human Adaptation of Ebola Virus during the West African Outbreak

Urbanowicz

McClure

Sakuntabhai

et al. 2016

Cell

192

188

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“…C-type lectins such as DC-SIGN and DC-SIGNR are thought to serve as adherence factors for EBOV (26). Other plasma membrane-associated proteins have been implicated in EBOV uptake including folate receptor alpha and the tyrosine kinase receptor Axl (6,35,36,38), but the physical interaction of EBOV GP and these proteins has not been demonstrated, and cells that do not express these proteins are permissive for EBOV GP-mediated virion uptake.…”

Section: Additionally Vector Transduction Was Elevated In Cells Thatmentioning

confidence: 99%

Rho GTPases Modulate Entry of Ebola Virus and Vesicular Stomatitis Virus Pseudotyped Vectors

Quinn

Brindley²,

Weller

et al. 2009

J Virol

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To explore mechanisms of entry for Ebola virus (EBOV) glycoprotein (GP) pseudotyped virions, we used comparative gene analysis to identify genes whose expression correlated with viral transduction. Candidate genes were identified by using EBOV GP pseudotyped virions to transduce human tumor cell lines that had previously been characterized by cDNA microarray. Transduction profiles for each of these cell lines were generated, and a significant positive correlation was observed between RhoC expression and permissivity for EBOV vector transduction. This correlation was not specific for EBOV vector alone as RhoC also correlated highly with transduction of vesicular stomatitis virus GP (VSVG) pseudotyped vector. Levels of RhoC protein in EBOV and VSV permissive and nonpermissive cells were consistent with the cDNA gene array findings. Additionally, vector transduction was elevated in cells that expressed high levels of endogenous RhoC but not RhoA. RhoB and RhoC overexpression significantly increased EBOV GP and VSVG pseudotyped vector transduction but had minimal effect on human immunodeficiency virus (HIV) GP pseudotyped HIV or adeno-associated virus 2 vector entry, indicating that not all virus uptake was enhanced by expression of these molecules. RhoB and RhoC overexpression also significantly enhanced VSV infection. Similarly, overexpression of RhoC led to a significant increase in fusion of EBOV virus-like particles. Finally, ectopic expression of RhoC resulted in increased nonspecific endocytosis of fluorescent dextran and in formation of increased actin stress fibers compared to RhoA-transfected cells, suggesting that RhoC is enhancing macropinocytosis. In total, our studies implicate RhoB and RhoC in enhanced productive entry of some pseudovirions and suggest the involvement of actin-mediated macropinocytosis as a mechanism of uptake of EBOV GP and VSVG pseudotyped viral particles.Enveloped viruses enter cells by a variety of different pathways. Productive internalization of enveloped viruses with targeted cells is mediated through interactions of the viral glycoprotein(s) (GPs) with moieties on the surface of the cell. In general, enveloped viral entry occurs through viral adherence to the cell surface, interaction with a specific plasma membrane-associated receptor that results in a series of GP conformational changes leading to fusion of viral and cellular membranes, and delivery of the viral core particle into the cytoplasm. Fusion of the two membranes can occur at the plasma membrane or by uptake of the intact virions into endosomes with subsequent membrane fusion between the viral membrane and the lipid bilayer of the endocytic vesicle. Human immunodeficiency virus (HIV) is an example of a virus that fuses directly to the plasma membrane (5), whereas influenza virus must be internalized into acidified vesicles where the appropriate GP conformational changes can occur, mediating membrane fusion (21). Most enveloped viruses that enter through vesicles utilize a low-pH environment to mediate the necessary...

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“…The N-terminal GP 1 subunit has a mass of over 150 kDa and contains a putative receptor binding domain (RBD) as well as a highly glycosylated mucin-like domain, while the C-terminal GP 2 has a mass of roughly 20 kDa and contains the fusion machinery as well as the transmembrane anchor. It is thought that EBOV GP 1,2 mediates initial attachment to host cells by binding to lectins such as DC-SIGN, L-SIGN, and hMGL (4)(5)(6). These initial attachment events are followed by internalization of the virus via macropinocytosis and trafficking of virus-containing macropinosomes to the endolysosomal pathway (7)(8)(9).…”

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confidence: 99%

“…While a great deal of work has examined how modifications to EBOV GP 1,2 affect its ability to mediate host cell attachment and fusion (5,29,30), there is little information on the effect of GP 1,2 expression levels on virus production and infectivity. EBOV, like other members of Mononegavirales, employs a very simple regulatory mechanism for gene expression, in which the order of genes from 3= to 5= on the negative-sense genome largely dictates the level of each gene's expression (31).…”

mentioning

confidence: 99%

Less Is More: Ebola Virus Surface Glycoprotein Expression Levels Regulate Virus Production and Infectivity

Mohan

et al. 2015

J Virol

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The Ebola virus (EBOV) surface glycoprotein (GP 1,2 ) mediates host cell attachment and fusion and is the primary target for host neutralizing antibodies. Expression of GP 1,2 at high levels disrupts normal cell physiology, and EBOV uses an RNA-editing mechanism to regulate expression of the GP gene. In this study, we demonstrate that high levels of GP 1,2 expression impair production and release of EBOV virus-like particles (VLPs) as well as infectivity of GP 1,2 -pseudotyped viruses. We further show that this effect is mediated through two mechanisms. First, high levels of GP 1,2 expression reduce synthesis of other proteins needed for virus assembly. Second, viruses containing high levels of GP 1,2 are intrinsically less infectious, possibly due to impaired receptor binding or endosomal processing. Importantly, proteolysis can rescue the infectivity of high-GP 1,2 -containing viruses. Taken together, our findings indicate that GP 1,2 expression levels have a profound effect on factors that contribute to virus fitness and that RNA editing may be an important mechanism employed by EBOV to regulate GP 1,2 expression in order to optimize virus production and infectivity. IMPORTANCEThe Ebola virus (EBOV), as well as other members of the Filoviridae family, causes severe hemorrhagic fever that is highly lethal, with up to 90% mortality. The EBOV surface glycoprotein (GP 1,2 ) plays important roles in virus infection and pathogenesis, and its expression is tightly regulated by an RNA-editing mechanism during virus replication. Our study demonstrates that the level of GP 1,2 expression profoundly affects virus particle production and release and uncovers a new mechanism by which Ebola virus infectivity is regulated by the level of GP 1,2 expression. These findings extend our understanding of EBOV infection and replication in adaptation of host environments, which will aid the development of countermeasures against EBOV infection.

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The Signal Peptide of the Ebolavirus Glycoprotein Influences Interaction with the Cellular Lectins DC-SIGN and DC-SIGNR

Cited by 53 publications

References 69 publications

Human Adaptation of Ebola Virus during the West African Outbreak

Human Adaptation of Ebola Virus during the West African Outbreak

Rho GTPases Modulate Entry of Ebola Virus and Vesicular Stomatitis Virus Pseudotyped Vectors

Less Is More: Ebola Virus Surface Glycoprotein Expression Levels Regulate Virus Production and Infectivity

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