Genetic analysis of heptad-repeat regions in the G2 fusion subunit of the Junín arenavirus envelope glycoprotein

Joanne York; Sudhakar S. Agnihothram; Victor Romanowski; Jack H. Nunberg

doi:10.1016/j.virol.2005.08.030

Genetic analysis of heptad-repeat regions in the G2 fusion subunit of the Junín arenavirus envelope glycoprotein

Joanne York
, Sudhakar S. Agnihothram
, Victor Romanowski
, Jack H. Nunberg

Montana Biotechnology Center

Research output: Contribution to journal › Article › peer-review

48 Scopus citations

Abstract

The G2 fusion subunit of the Junín virus envelope glycoprotein GP-C contains two hydrophobic heptad-repeat regions that are postulated to form a six-helix bundle structure required for the membrane fusion activity of Class I viral fusion proteins. We have investigated the role of these heptad-repeat regions and, specifically, the importance of the putative interhelical a and d position sidechains by using alanine-scanning mutagenesis. All the mutant glycoproteins were expressed and transported to the cell surface. Proteolytic maturation at the subtilisin kexin isozyme-1/site-1-protease (SKI-1/S1P) cleavage site was observed in all but two of the mutants. Among the adequately cleaved mutant glycoproteins, four positions in the N-terminal region (I333, L336, L347 and L350) and two positions in the C-terminal region (R392 and W395) were shown to be important determinants of cell-cell fusion. Taken together, our results indicate that α-helical coiled-coil structures are likely critical in promoting arenavirus membrane fusion. These findings support the inclusion of the arenavirus GP-C among the Class I viral fusion proteins and suggest pharmacologic and immunologic strategies for targeting arenavirus infection and hemorrhagic fever.

Original language	English
Pages (from-to)	267-274
Number of pages	8
Journal	Virology
Volume	343
Issue number	2
DOIs	https://doi.org/10.1016/j.virol.2005.08.030
State	Published - Dec 20 2005

Funding

We thank Dr. Min Lu (Weill Medical College of Cornell University, New York) for continued discussions throughout this work and for access to his unpublished data. We are grateful to Drs. Tom Ksiasek and Tony Sanchez (Special Pathogens Branch, CDC, Atlanta) for monoclonal antibodies and to Dr. Meg Trahey (The University of Montana) for useful comments during preparation of the manuscript. Technical assistance in plasmid preparation was provided by Kimberly Hardwick, and we thank Kathryn Follis for manuscript editing. V.R. holds a research career award from Consejo Nacional de Investigaciones Científicas y Téchnicas (CONICET), Argentina. This project was supported by a grant to J.H.N. from the U.S. National Institutes of Health (AI059355).

Funder number
R21AI059355

Keywords

Arenavirus
Envelope glycoprotein
GP-C
Junín virus or Argentine hemorrhagic fever virus
Membrane fusion
Mutagenesis
Six-helix bundle

Access to Document

10.1016/j.virol.2005.08.030

Cite this

@article{ee8a6649274b42929dd58d0b9243ee38,

title = "Genetic analysis of heptad-repeat regions in the G2 fusion subunit of the Jun{\'i}n arenavirus envelope glycoprotein",

abstract = "The G2 fusion subunit of the Jun{\'i}n virus envelope glycoprotein GP-C contains two hydrophobic heptad-repeat regions that are postulated to form a six-helix bundle structure required for the membrane fusion activity of Class I viral fusion proteins. We have investigated the role of these heptad-repeat regions and, specifically, the importance of the putative interhelical a and d position sidechains by using alanine-scanning mutagenesis. All the mutant glycoproteins were expressed and transported to the cell surface. Proteolytic maturation at the subtilisin kexin isozyme-1/site-1-protease (SKI-1/S1P) cleavage site was observed in all but two of the mutants. Among the adequately cleaved mutant glycoproteins, four positions in the N-terminal region (I333, L336, L347 and L350) and two positions in the C-terminal region (R392 and W395) were shown to be important determinants of cell-cell fusion. Taken together, our results indicate that α-helical coiled-coil structures are likely critical in promoting arenavirus membrane fusion. These findings support the inclusion of the arenavirus GP-C among the Class I viral fusion proteins and suggest pharmacologic and immunologic strategies for targeting arenavirus infection and hemorrhagic fever.",

keywords = "Arenavirus, Envelope glycoprotein, GP-C, Jun{\'i}n virus or Argentine hemorrhagic fever virus, Membrane fusion, Mutagenesis, Six-helix bundle",

author = "Joanne York and Agnihothram, \{Sudhakar S.\} and Victor Romanowski and Nunberg, \{Jack H.\}",

note = "Funding Information: We thank Dr. Min Lu (Weill Medical College of Cornell University, New York) for continued discussions throughout this work and for access to his unpublished data. We are grateful to Drs. Tom Ksiasek and Tony Sanchez (Special Pathogens Branch, CDC, Atlanta) for monoclonal antibodies and to Dr. Meg Trahey (The University of Montana) for useful comments during preparation of the manuscript. Technical assistance in plasmid preparation was provided by Kimberly Hardwick, and we thank Kathryn Follis for manuscript editing. V.R. holds a research career award from Consejo Nacional de Investigaciones Cient{\'i}ficas y T{\'e}chnicas (CONICET), Argentina. This project was supported by a grant to J.H.N. from the U.S. National Institutes of Health (AI059355).",

year = "2005",

month = dec,

day = "20",

doi = "10.1016/j.virol.2005.08.030",

language = "English",

volume = "343",

pages = "267--274",

journal = "Virology",

issn = "0042-6822",

publisher = "Academic Press Inc.",

number = "2",

}

TY - JOUR

T1 - Genetic analysis of heptad-repeat regions in the G2 fusion subunit of the Junín arenavirus envelope glycoprotein

AU - York, Joanne

AU - Agnihothram, Sudhakar S.

AU - Romanowski, Victor

AU - Nunberg, Jack H.

N1 - Funding Information: We thank Dr. Min Lu (Weill Medical College of Cornell University, New York) for continued discussions throughout this work and for access to his unpublished data. We are grateful to Drs. Tom Ksiasek and Tony Sanchez (Special Pathogens Branch, CDC, Atlanta) for monoclonal antibodies and to Dr. Meg Trahey (The University of Montana) for useful comments during preparation of the manuscript. Technical assistance in plasmid preparation was provided by Kimberly Hardwick, and we thank Kathryn Follis for manuscript editing. V.R. holds a research career award from Consejo Nacional de Investigaciones Científicas y Téchnicas (CONICET), Argentina. This project was supported by a grant to J.H.N. from the U.S. National Institutes of Health (AI059355).

PY - 2005/12/20

Y1 - 2005/12/20

N2 - The G2 fusion subunit of the Junín virus envelope glycoprotein GP-C contains two hydrophobic heptad-repeat regions that are postulated to form a six-helix bundle structure required for the membrane fusion activity of Class I viral fusion proteins. We have investigated the role of these heptad-repeat regions and, specifically, the importance of the putative interhelical a and d position sidechains by using alanine-scanning mutagenesis. All the mutant glycoproteins were expressed and transported to the cell surface. Proteolytic maturation at the subtilisin kexin isozyme-1/site-1-protease (SKI-1/S1P) cleavage site was observed in all but two of the mutants. Among the adequately cleaved mutant glycoproteins, four positions in the N-terminal region (I333, L336, L347 and L350) and two positions in the C-terminal region (R392 and W395) were shown to be important determinants of cell-cell fusion. Taken together, our results indicate that α-helical coiled-coil structures are likely critical in promoting arenavirus membrane fusion. These findings support the inclusion of the arenavirus GP-C among the Class I viral fusion proteins and suggest pharmacologic and immunologic strategies for targeting arenavirus infection and hemorrhagic fever.

AB - The G2 fusion subunit of the Junín virus envelope glycoprotein GP-C contains two hydrophobic heptad-repeat regions that are postulated to form a six-helix bundle structure required for the membrane fusion activity of Class I viral fusion proteins. We have investigated the role of these heptad-repeat regions and, specifically, the importance of the putative interhelical a and d position sidechains by using alanine-scanning mutagenesis. All the mutant glycoproteins were expressed and transported to the cell surface. Proteolytic maturation at the subtilisin kexin isozyme-1/site-1-protease (SKI-1/S1P) cleavage site was observed in all but two of the mutants. Among the adequately cleaved mutant glycoproteins, four positions in the N-terminal region (I333, L336, L347 and L350) and two positions in the C-terminal region (R392 and W395) were shown to be important determinants of cell-cell fusion. Taken together, our results indicate that α-helical coiled-coil structures are likely critical in promoting arenavirus membrane fusion. These findings support the inclusion of the arenavirus GP-C among the Class I viral fusion proteins and suggest pharmacologic and immunologic strategies for targeting arenavirus infection and hemorrhagic fever.

KW - Arenavirus

KW - Envelope glycoprotein

KW - GP-C

KW - Junín virus or Argentine hemorrhagic fever virus

KW - Membrane fusion

KW - Mutagenesis

KW - Six-helix bundle

UR - https://www.scopus.com/pages/publications/27744594720

U2 - 10.1016/j.virol.2005.08.030

DO - 10.1016/j.virol.2005.08.030

M3 - Article

C2 - 16169032

AN - SCOPUS:27744594720

SN - 0042-6822

VL - 343

SP - 267

EP - 274

JO - Virology

JF - Virology

IS - 2

ER -

Genetic analysis of heptad-repeat regions in the G2 fusion subunit of the Junín arenavirus envelope glycoprotein

Abstract

Funding

Keywords

Access to Document

Other files and links

Fingerprint

Cite this