Cysteines in the stalk of the nipah virus G glycoprotein are located in a distinct subdomain critical for fusion activation

Dianna Maar; Brooke Harmon; David Chu; Belinda Schulz; Hector C Aguilar; Benhur Lee; Oscar A Negrete

doi:10.1128/JVI.00076-12

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Cysteines in the stalk of the nipah virus G glycoprotein are located in a distinct subdomain critical for fusion activation

Journal article

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Cysteines in the stalk of the nipah virus G glycoprotein are located in a distinct subdomain critical for fusion activation

Dianna Maar, Brooke Harmon, David Chu, Belinda Schulz, Hector C Aguilar, Benhur Lee and Oscar A Negrete

Journal of virology, Vol.86(12), pp.6632-6642

06/2012

DOI: https://doi.org/10.1128/JVI.00076-12

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https://hdl.handle.net/2376/105827

PMCID: PMC3393546

PMID: 22496210

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Abstract

Protein Structure, Tertiary

Amino Acid Sequence

Cell Line

Viral Envelope Proteins - genetics

Humans

Molecular Sequence Data

Cysteine - chemistry

Virus Internalization

Amino Acid Motifs

Cysteine - genetics

Nipah Virus - physiology

Sequence Alignment

Animals

Nipah Virus - genetics

Viral Envelope Proteins - chemistry

Viral Envelope Proteins - metabolism

Cysteine - metabolism

Dimerization

Henipavirus Infections - virology

Nipah Virus - chemistry

Paramyxoviruses initiate entry through the concerted action of the tetrameric attachment glycoprotein (HN, H, or G) and the trimeric fusion glycoprotein (F). The ectodomains of HN/H/G contain a stalk region important for oligomeric stability and for the F triggering resulting in membrane fusion. Paramyxovirus HN, H, and G form a dimer-of-dimers consisting of disulfide-linked dimers through their stalk domain cysteines. The G attachment protein stalk domain of the highly pathogenic Nipah virus (NiV) contains a distinct but uncharacterized cluster of three cysteine residues (C146, C158, C162). On the basis of a panoply of assays, we report that C158 and C162 of NiV-G likely mediate covalent subunit dimerization, while C146 mediates the stability of higher-order oligomers. For HN or H, mutation of stalk cysteines attenuates but does not abrogate the ability to trigger fusion. In contrast, the NiV-G stalk cysteine mutants were completely deficient in triggering fusion, even though they could still bind the ephrinB2 receptor and associate with F. Interestingly, all cysteine stalk mutants exhibited constitutive exposure of the Mab45 receptor binding-enhanced epitope, previously implicated in F triggering. The enhanced binding of Mab45 to the cysteine mutants relative to wild-type NiV-G, without the addition of the receptor, implicates the stalk cysteines in the stabilization of a pre-receptor-bound conformation and the regulation of F triggering. Sequence alignments revealed that the stalk cysteines were adjacent to a proline-rich microdomain unique to the Henipavirus genus. Our data propose that the cysteine cluster in the NiV-G stalk functions to maintain oligomeric stability but is more importantly involved in stabilizing a unique microdomain critical for triggering fusion.

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Title: Cysteines in the stalk of the nipah virus G glycoprotein are located in a distinct subdomain critical for fusion activation
Creators: Dianna Maar - Biotechnology and Bioengineering Department, Sandia National Laboratories, Livermore, California, USA
Brooke Harmon
David Chu
Belinda Schulz
Hector C Aguilar
Benhur Lee
Oscar A Negrete
Publication Details: Journal of virology, Vol.86(12), pp.6632-6642
Academic Unit: Paul G. Allen School for Global Animal Health
Publisher: United States
Grant note: AI069317 / NIAID NIH HHS R01 AI069317 / NIAID NIH HHS U54 AI065359 / NIAID NIH HHS
Identifiers: 99900547060901842
Language: English
Resource Type: Journal article