Furin cleavage of the Moloney murine leukemia virus Env precursor reorganizes the spike structure

Mathilda Sjöberg, Shang Rung Wu, Robin Löving, Kimmo Rantalainen, Birgitta Lindqvist, Henrik Garoff

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

The trimeric Moloney murine leukemia virus Env protein matures by two proteolytic cleavages. First, furin cleaves the Env precursor into the surface (SU) and transmembrane (TM) subunits in the cell and then the viral protease cleaves the R-peptide from TM in new virus. Here we analyzed the structure of the furin precursor, by cryoelectron microscopy. We transfected 293T cells with a furin cleavage site provirus mutant, R466G/K468G, and produced the virus in the presence of amprenavir to also inhibit the R-peptide cleavage. Although Env incorporation into particles was inhibited, enough precursor could be isolated and analyzed by cryoelectron microscopy to yield a 3D structure at 22 Å resolution. This showed an open cage-like structure like that of the R-peptide precursor and the mature Env described before. However, the middle protrusion of the protomeric unit, so prominently pointing out from the side of the more mature forms of the Env, was absent. Instead, there was extra density in the top protrusion. This suggested that the C-terminal SU domain was associated alongside the receptor binding N-terminal SU domain in the furin precursor. This was supported by mapping with a SU C-terminal domain-specific antigen binding fragment. We concluded that furin cleavage not only separates the subunits and liberates the fusion peptide at the end of TM but also allows the C-terminal domain to relocate into a peripheral position. This conformational change might explain how the C-terminal domain of SU gains the potential to undergo disulfide isomerization, an event that facilitates membrane fusion.

Original languageEnglish
Pages (from-to)6034-6039
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume111
Issue number16
DOIs
Publication statusPublished - 2014 Apr 22

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Furin
Moloney murine leukemia virus
Cryoelectron Microscopy
env Gene Products
Viruses
Proviruses
Membrane Fusion
HEK293 Cells
Disulfides
Peptide Hydrolases
Antigens
Peptides
R peptide

All Science Journal Classification (ASJC) codes

  • General

Cite this

Sjöberg, Mathilda ; Wu, Shang Rung ; Löving, Robin ; Rantalainen, Kimmo ; Lindqvist, Birgitta ; Garoff, Henrik. / Furin cleavage of the Moloney murine leukemia virus Env precursor reorganizes the spike structure. In: Proceedings of the National Academy of Sciences of the United States of America. 2014 ; Vol. 111, No. 16. pp. 6034-6039.
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Furin cleavage of the Moloney murine leukemia virus Env precursor reorganizes the spike structure. / Sjöberg, Mathilda; Wu, Shang Rung; Löving, Robin; Rantalainen, Kimmo; Lindqvist, Birgitta; Garoff, Henrik.

In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 111, No. 16, 22.04.2014, p. 6034-6039.

Research output: Contribution to journalArticle

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T1 - Furin cleavage of the Moloney murine leukemia virus Env precursor reorganizes the spike structure

AU - Sjöberg, Mathilda

AU - Wu, Shang Rung

AU - Löving, Robin

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