Identification of a Region in the Stalk Domain of the Nipah Virus Receptor Binding Protein That Is Critical for Fusion Activation

Talekar, Aparna; DeVito, Ilaria; Salah, Zuhair; Palmer, Samantha G.; Chattopadhyay, Anasuya; Rose, John K.; Xu, Rui; Wilson, Ian A.; Moscona, Anne; Porotto, Matteo

doi:10.1128/jvi.01646-13

Cited by 22 publications

(27 citation statements)

References 65 publications

(108 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A model for morbillivirus F activation was recently proposed, in which the stalk domain unfolds to expose a conserved region containing a proline; if unfolding is blocked by introducing disulfide bonds in the stalk domain, F activation does not occur (46). The results presented here suggest that the globular head of NDV can induce such an unfolding in the stalk of MV H. For NiV G, we have proposed that flexibility in the stalk is required for proper fusion activation (50). For MV, too, stalk flexibility is important for fusion activation (46,48), and a recent report showed that short MV H stems, provided they are properly stabilized, are sufficient for activation of F. In that work, it appeared that either excessive or insufficient tetramer stabilization could deter fusion promotion (43).…”

Section: Discussionmentioning

confidence: 51%

Measles Virus Fusion Machinery Activated by Sialic Acid Binding Globular Domain

Talekar

Moscona

Porotto

2013

J Virol

Self Cite

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 51%

Measles Virus Fusion Machinery Activated by Sialic Acid Binding Globular Domain

Talekar

Moscona

Porotto

2013

J Virol

Self Cite

View full text Add to dashboard Cite

“…Nipah's G protein assembles as a homo-tetramer and its ectodomain contains both the ephrin binding and F activation sites (4,5,(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24). The F activation site is located in the N-terminal portion of the ectodomain (Fig.…”

Section: Introductionmentioning

confidence: 99%

“…The F activation site is located in the N-terminal portion of the ectodomain (Fig. 1), which is generally referred to as the stalk domain, or the F activation domain (FAD) (13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24). The receptor binding sites are located in the C-terminal portion of the ectodomain, and are >2 nm away from the F activation site.…”

Section: Introductionmentioning

confidence: 99%

Stimulation of Nipah Fusion: Small Intradomain Changes Trigger Extensive Interdomain Rearrangements

Dutta¹,

Siddiqui²,

Botlani³

et al. 2016

Biophysical Journal

View full text Add to dashboard Cite

Nipah is an emerging paramyxovirus that is of serious concern to human health. It invades host cells using two of its membrane proteins-G and F. G binds to host ephrins and this stimulates G to activate F. Upon activation, F mediates virus-host membrane fusion. Here we focus on mechanisms that underlie the stimulation of G by ephrins. Experiments show that G interacts with ephrin and F through separate sites located on two different domains, the receptor binding domain (RBD) and the F activation domain (FAD). No models explain this allosteric coupling. In fact, the analogous mechanisms in other paramyxoviruses also remain undetermined. The structural organization of G is such that allosteric coupling must involve at least one of the two interfaces-the RBD-FAD interface and/or the RBD-RBD interface. Here we examine using molecular dynamics the effect of ephrin binding on the RBD-RBD interface. We find that despite inducing small changes in individual RBDs, ephrin reorients the RBD-RBD interface extensively, and in a manner that will enhance solvent exposure of the FAD. While this finding supports a proposed model of G stimulation, we also find from additional simulations that ephrin induces a similar RBD-RBD reorientation in a stimulation-deficient G mutant, V 209 VG / AAA. Together, our simulations suggest that while inter-RBD reorientation may be important, it is not, by itself, a sufficient condition for G stimulation. Additionally, we find that the mutation affects the conformational ensemble of RBD globally, including the RBD-FAD interface, suggesting the latter's role in G stimulation. Because ephrin induces small changes in individual RBDs, a proper analysis of conformational ensembles required that they are compared directly-we employ a method we developed recently, which we now release at SimTK, and show that it also performs excellently for non-Gaussian distributions.

show abstract

“…A dimer of dimers (tetramer) constitutes the functional unit for efficient fusion triggering (15). While any given attachment protein will only trigger its cognate fusion protein, key aspects of structure are conserved, as documented by the production of functional G-HN chimeric proteins (16)(17)(18)(19).…”

mentioning

confidence: 99%

The Measles Virus Hemagglutinin Stalk: Structures and Functions of the Central Fusion Activation and Membrane-Proximal Segments

Navaratnarajah

Kumar

Generous

et al. 2014

J Virol

View full text Add to dashboard Cite

The measles virus (MeV) membrane fusion apparatus consists of a fusion protein trimer and an attachment protein tetramer. To trigger membrane fusion, the heads of the MeV attachment protein, hemagglutinin (H), bind cellular receptors while the 96-residue-long H stalk transmits the triggering signal. Structural and functional studies of the triggering mechanism of other paramyxoviruses suggest that receptor binding to their hemagglutinin-neuraminidase (HN) results in signal transmission through the central segments of their stalks. To gain insight into H-stalk structure and function, we individually replaced its residues with cysteine. We then assessed how stable the mutant proteins are, how efficiently they can be cross-linked by disulfide bonds, whether cross-linking results in loss of function, and, in this case, whether disulfide bond reduction restores function. While many residues in the central segment of the stalk and in the spacer segment above it can be efficiently cross-linked by engineered disulfide bonds, we report here that residues 59 to 79 cannot, suggesting that the 20 membrane-proximal residues are not engaged in a tetrameric structure. Rescue-of-function studies by disulfide bond reduction resulted in the redefinition and extension of the central fusion-activation segment as covering residues 84 to 117. In particular, we identified four residues located between positions 92 and 99, the function of which cannot be restored by disulfide bond reduction after cysteine mutagenesis. These mutant H proteins reached the cell surface as complex oligomers but could not trigger membrane fusion. We discuss these observations in the context of the stalk exposure model of membrane fusion triggering by paramyxoviruses. IMPORTANCEMeasles virus, while being targeted for eradication, still causes significant morbidity and mortality. Here, we seek to understand how it enters cells by membrane fusion. Two viral integral membrane glycoproteins (hemagglutinin tetramers and fusion protein trimers) mediate the concerted receptor recognition and membrane fusion processes. Since previous studies have suggested that the hemagglutinin stalk transmits the triggering signal to the fusion protein trimer, we completed an analysis of its structure and function by systematic Cys mutagenesis. We report that while certain residues of the central stalk segment confer specificity to the interaction with the fusion protein trimer, others are necessary to allow folding of the H-oligomer in a standard conformation conducive to fusion triggering, and still other residues sustain the conformational change that transmits the fusiontriggering signal.

show abstract

Identification of a Region in the Stalk Domain of the Nipah Virus Receptor Binding Protein That Is Critical for Fusion Activation

Cited by 22 publications

References 65 publications

Measles Virus Fusion Machinery Activated by Sialic Acid Binding Globular Domain

Measles Virus Fusion Machinery Activated by Sialic Acid Binding Globular Domain

Stimulation of Nipah Fusion: Small Intradomain Changes Trigger Extensive Interdomain Rearrangements

The Measles Virus Hemagglutinin Stalk: Structures and Functions of the Central Fusion Activation and Membrane-Proximal Segments

Contact Info

Product

Resources

About