Cysteines flanking the internal fusion peptide are required for the avian sarcoma/leukosis virus glycoprotein to mediate the lipid mixing stage of fusion with high efficiency

Sue E. Delos, Matthew B. Brecher, Zaoying Chen, Deborah C. Melder, Mark J Federspiel, Judith M. White

Research output: Contribution to journalArticle

12 Scopus citations


We previously showed that the cysteines flanking the internal fusion peptide of the avian sarcoma/leukosis virus subtype A (ASLV-A) Env (EnvA) are important for infectivity and cell-cell fusion. Here we define the stage of fusion at which the cysteines are required. The flanking cysteines are dispensable for receptor-triggered membrane association but are required for the lipid mixing step of fusion, which, interestingly, displays a high pH onset and a biphasic profile. Second-site mutations that partially restore infection partially restore lipid mixing. These findings indicate that the cysteines flanking the internal fusion peptide of EnvA (and perhaps by analogy Ebola virus glycoprotein) are important for the foldback stage of the conformational changes that lead to membrane merger.

Original languageEnglish (US)
Pages (from-to)3131-3134
Number of pages4
JournalJournal of Virology
Issue number6
StatePublished - Mar 2008


ASJC Scopus subject areas

  • Immunology

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