The measles virus hemagglutinin stalk

Structures and functions of the central fusion activation and membrane-proximal segments

Chanakha K. Navaratnarajah, Swati Kumar, Alex Generous, Swapna Apte-Sengupta, Mathieu Mateo, Roberto Cattaneo

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

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.

Original languageEnglish (US)
Pages (from-to)6158-6167
Number of pages10
JournalJournal of Virology
Volume88
Issue number11
DOIs
StatePublished - 2014

Fingerprint

Measles virus
Membrane Fusion
disulfide bonds
Hemagglutinins
hemagglutinins
Disulfides
Respirovirus
Mutant Proteins
proteins
Cysteine
cysteine
exposure models
Virus Attachment
Virus Internalization
mutants
receptors
Proteins
sialidase
Neuraminidase
crosslinking

ASJC Scopus subject areas

  • Immunology
  • Virology

Cite this

The measles virus hemagglutinin stalk : Structures and functions of the central fusion activation and membrane-proximal segments. / Navaratnarajah, Chanakha K.; Kumar, Swati; Generous, Alex; Apte-Sengupta, Swapna; Mateo, Mathieu; Cattaneo, Roberto.

In: Journal of Virology, Vol. 88, No. 11, 2014, p. 6158-6167.

Research output: Contribution to journalArticle

Navaratnarajah, Chanakha K. ; Kumar, Swati ; Generous, Alex ; Apte-Sengupta, Swapna ; Mateo, Mathieu ; Cattaneo, Roberto. / The measles virus hemagglutinin stalk : Structures and functions of the central fusion activation and membrane-proximal segments. In: Journal of Virology. 2014 ; Vol. 88, No. 11. pp. 6158-6167.
@article{639e364d986e4a029cbf324771c6a409,
title = "The measles virus hemagglutinin stalk: Structures and functions of the central fusion activation and membrane-proximal segments",
abstract = "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.",
author = "Navaratnarajah, {Chanakha K.} and Swati Kumar and Alex Generous and Swapna Apte-Sengupta and Mathieu Mateo and Roberto Cattaneo",
year = "2014",
doi = "10.1128/JVI.02846-13",
language = "English (US)",
volume = "88",
pages = "6158--6167",
journal = "Journal of Virology",
issn = "0022-538X",
publisher = "American Society for Microbiology",
number = "11",

}

TY - JOUR

T1 - The measles virus hemagglutinin stalk

T2 - Structures and functions of the central fusion activation and membrane-proximal segments

AU - Navaratnarajah, Chanakha K.

AU - Kumar, Swati

AU - Generous, Alex

AU - Apte-Sengupta, Swapna

AU - Mateo, Mathieu

AU - Cattaneo, Roberto

PY - 2014

Y1 - 2014

N2 - 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.

AB - 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.

UR - http://www.scopus.com/inward/record.url?scp=84899850258&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84899850258&partnerID=8YFLogxK

U2 - 10.1128/JVI.02846-13

DO - 10.1128/JVI.02846-13

M3 - Article

VL - 88

SP - 6158

EP - 6167

JO - Journal of Virology

JF - Journal of Virology

SN - 0022-538X

IS - 11

ER -