Membrane-induced step in the activation of sendai virus fusion protein 1 1Edited by A. R. Fersht

Ben-Efraim, Iris; Kliger, Yossef; Hermesh, Chen; Shai, Yechiel

doi:10.1006/jmbi.1998.2370

Cited by 39 publications

(34 citation statements)

References 72 publications

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“…When fluorophore molecules are in close proximity, rhodamine emission diminishes (31,55). Thus, Rho quenching efficiency correlates with the aggregation state of the peptide.…”

Section: Resultsmentioning

confidence: 99%

Sphingomyelin and Cholesterol Promote HIV-1 gp41 Pretransmembrane Sequence Surface Aggregation and Membrane Restructuring

Sáez‐Cirión

Nir

Lorizate

et al. 2002

Journal of Biological Chemistry

122

136

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The interfacial sequence DKWASLWNWFNITNWL-WYIK, preceding the transmembrane anchor of gp41 glycoprotein subunit, has been shown to be essential for fusion activity and incorporation into virions. HIV c , a peptide representing this region, formed lytic pores in liposomes composed of the main lipids occurring in the human immunodeficiency virus, type 1 (HIV-1), envelope, i.e. 1-palmitoyl-2-oleoylphosphatidylcholine (POPC):sphingomyelin (SPM):cholesterol (Chol) (1:1:1 mole ratio), at low (>1:10,000) peptide-to-lipid mole ratio, and promoted the mixing of vesicular lipids at >1: 1000 peptide-to-lipid mole ratios. Inclusion of SPM or Chol in POPC membranes had different effects. Whereas SPM sustained pore formation, Chol promoted fusion activity. Even if partitioning into membranes was not affected in the absence of both SPM and Chol, HIV c had virtually no effect on POPC vesicles. Conditions described to disturb occurrence of lateral separation of phases in these systems reproduced the high peptidedose requirements for leakage as found in pure POPC vesicles and inhibited fusion. Surface aggregation assays using rhodamine-labeled peptides demonstrated that SPM and Chol promoted HIV c self-aggregation in membranes. Employing head-group fluorescent phospholipid analogs in planar supported lipid layers, we were able to discern HIV c clusters associated to ordered domains. Our results support the notion that the pretransmembrane sequence may participate in the clustering of gp41 monomers within the HIV-1 envelope, and in bilayer architecture destabilization at the loci of fusion.

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“…When fluorophore molecules are in close proximity, rhodamine emission diminishes (31,55). Thus, Rho quenching efficiency correlates with the aggregation state of the peptide.…”

Section: Resultsmentioning

confidence: 99%

Sphingomyelin and Cholesterol Promote HIV-1 gp41 Pretransmembrane Sequence Surface Aggregation and Membrane Restructuring

Sáez‐Cirión

Nir

Lorizate

et al. 2002

Journal of Biological Chemistry

122

136

View full text Add to dashboard Cite

show abstract

“…Examples include peptides derived from envelope proteins of HIV (Wild et al, , 1994b Jiang et al, 1993a,b;Judice et al, 1997) and paramyxoviruses (Rapaport et al, 1995;Lambert et al, 1996;Yao and Compans, 1996;Ghosh et al, 1997;Wild and Buckland, 1997;Young et al, 1997;Ben-Efraim et al, 1999). These peptides are presumed to mimic functional domains of the paramyxovirus and HIV fusion proteins and therefore disrupt the activity of these proteins (Young et al, 1997).…”

Section: Introductionmentioning

confidence: 99%

A Discrete Stage of Baculovirus GP64-mediated Membrane Fusion

Kingsley

Behbahani

Rashtian

et al. 1999

MBoC

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Viral fusion protein trimers can play a critical role in limiting lipids in membrane fusion. Because the trimeric oligomer of many viral fusion proteins is often stabilized by hydrophobic 4-3 heptad repeats, higher-order oligomers might be stabilized by similar sequences. There is a hydrophobic 4-3 heptad repeat contiguous to a putative oligomerization domain of Autographa californica multicapsid nucleopolyhedrovirus envelope glycoprotein GP64. We performed mutagenesis and peptide inhibition studies to determine if this sequence might play a role in catalysis of membrane fusion. First, leucine-to-alanine mutants within and flanking the amino terminus of the hydrophobic 4-3 heptad repeat motif that oligomerize into trimers and traffic to insect Sf9 cell surfaces were identified. These mutants retained their wild-type conformation at neutral pH and changed conformation in acidic conditions, as judged by the reactivity of a conformationally sensitive mAb. These mutants, however, were defective for membrane fusion. Second, a peptide encoding the portion flanking the GP64 hydrophobic 4-3 heptad repeat was synthesized. Adding peptide led to inhibition of membrane fusion, which occurred only when the peptide was present during low pH application. The presence of peptide during low pH application did not prevent low pH-induced conformational changes, as determined by the loss of a conformationally sensitive epitope. In control experiments, a peptide of identical composition but different sequence, or a peptide encoding a portion of the Ebola GP heptad motif, had no effect on GP64-mediated fusion. Furthermore, when the hemagglutinin (X31 strain) fusion protein of influenza was functionally expressed in Sf9 cells, no effect on hemagglutinin-mediated fusion was observed, suggesting that the peptide does not exert nonspecific effects on other fusion proteins or cell membranes. Collectively, these studies suggest that the specific peptide sequences of GP64 that are adjacent to and include portions of the hydrophobic 4-3 heptad repeat play a dynamic role in membrane fusion at a stage that is downstream of the initiation of protein conformational changes but upstream of lipid mixing. INTRODUCTIONThe mechanism of membrane fusion is currently a field of intense investigation, both for intracellular trafficking and enveloped viral infection. For viral fusion protein function, we have previously suggested that fusion protein oligomers form transient and cooperative higher-order structures or rings . These transient ring structures are proposed to facilitate conversion of kinetic energy, released during protein conformational change, into work on the target and host membranes required for membrane fusion. Indeed, biochemical evidence for baculovirus GP64 aggregates during membrane fusion has recently been reported (Markovic et al. 1998). Whether and how viral fusion proteins might function in a coordinated and cooperative manner is a major question in the field of membrane fusion. Because hydrophobic 4-3 heptad repeats are observed...

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“…The F protein, in type I orientation, forms homotrimers, while homodimers or homotetramers have been suggested as functional units for attachment proteins of different Paramyxovirinae subfamily members (7,14,28,41,49,50,66). For entry, upon receptor binding, the attachment protein is considered to initiate a series of conformational rearrangements in the metastable prefusion F protein (15, 77), which ultimately brings together transmembrane domains and fusion peptides and, thus, donor and target membranes (3,32,45,53,80).Multiple studies have demonstrated that specific interactions between compatible F and attachment proteins of paramyxovirinae are imperative for the formation of functional fusion complexes (6,29,36,42,43,56,75). However, the molecular nature of these interactions and the spatial organization of functional glycoprotein hetero-oligomers remain largely unknown.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

Probing the Spatial Organization of Measles Virus Fusion Complexes

Paal

Brindley

Clair

et al. 2009

J Virol

147

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The spatial organization of metastable paramyxovirus fusion (F) and attachment glycoprotein heterooligomers is largely unknown. To further elucidate the organization of functional fusion complexes of measles virus (MeV), an archetype of the paramyxovirus family, we subjected central predictions of alternative docking models to experimental testing using three distinct approaches. Carbohydrate shielding through engineered N-glycans indicates close proximity of a membrane-distal, but not membrane-proximal, section of the MeV attachment (H) protein stalk domain to F. Directed mutagenesis of this section identified residues 111, 114, and 118 as modulators of avidity of glycoprotein interactions and determinants of F triggering. Stalk-length variation through deletion or insertion of HR elements at positions flanking this section demonstrates that the location of the stalk segment containing these residues cannot be altered in functional fusion complexes. In contrast, increasing the distance between the H head domains harboring the receptor binding sites and this section through insertion of structurally rigid ␣-helical domains with a pitch of up to approximately 75 Å downstream of stalk position 118 partially maintains functionality in transient expression assays and supports efficient growth of recombinant virions. In aggregate, these findings argue against specific protein-protein contacts between the H head and F head domains but instead support a docking model that is characterized by short-range contacts between the prefusion F head and the attachment protein stalk, possibly involving H residues 111, 114, and 118, and extension of the head domain of the attachment protein above prefusion F.Paramyxoviruses infect cells through fusion of the viral envelope with target cell membranes. For all members of the Paramyxovirinae subfamily, this involves the concerted action of two envelope glycoproteins, the fusion (F) and attachment (H, HN, or G, depending on the Paramyxovirinae genus) proteins. Both proteins feature short lumenal tails, a single transmembrane domain, and large ectodomains. The F protein, in type I orientation, forms homotrimers, while homodimers or homotetramers have been suggested as functional units for attachment proteins of different Paramyxovirinae subfamily members (7,14,28,41,49,50,66). For entry, upon receptor binding, the attachment protein is considered to initiate a series of conformational rearrangements in the metastable prefusion F protein (15, 77), which ultimately brings together transmembrane domains and fusion peptides and, thus, donor and target membranes (3,32,45,53,80).Multiple studies have demonstrated that specific interactions between compatible F and attachment proteins of paramyxovirinae are imperative for the formation of functional fusion complexes (6,29,36,42,43,56,75). However, the molecular nature of these interactions and the spatial organization of functional glycoprotein hetero-oligomers remain largely unknown. Individual ectodomain and partial ectodomain crystal stru...

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Membrane-induced step in the activation of sendai virus fusion protein 1 1Edited by A. R. Fersht

Cited by 39 publications

References 72 publications

Sphingomyelin and Cholesterol Promote HIV-1 gp41 Pretransmembrane Sequence Surface Aggregation and Membrane Restructuring

Sphingomyelin and Cholesterol Promote HIV-1 gp41 Pretransmembrane Sequence Surface Aggregation and Membrane Restructuring

A Discrete Stage of Baculovirus GP64-mediated Membrane Fusion

Probing the Spatial Organization of Measles Virus Fusion Complexes

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