Palmitoylation of the cysteine-rich endodomain of the SARS-coronavirus spike glycoprotein is important for spike-mediated cell fusion

Journal Article · Tue Apr 10 04:00:00 EDT 2007 · Virology

DOI:https://doi.org/10.1016/j.virol.2006.10.034· OSTI ID:20977007

Petit, Chad M ^[1]; Chouljenko, Vladimir N ^[1]; Iyer, Arun ^[1]; Colgrove, Robin ^[2]; Farzan, Michael ^[3]; Knipe, David M ^[2]; Kousoulas, K G ^[4]

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1. Division of Biotechnology and Molecular Medicine (BIOMMED) (United States)
2. Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115 (United States)
3. Partners AIDS Research Center, Brigham and Women's Hospital, Department of Medicine - Microbiology and Molecular Genetics, Harvard Medical School, Boston, MA 02115 (United States)
4. Division of Biotechnology and Molecular Medicine (BIOMMED) (United States) and Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803 (United States)

The SARS-coronavirus (SARS-CoV) is the etiological agent of the severe acute respiratory syndrome (SARS). The SARS-CoV spike (S) glycoprotein mediates membrane fusion events during virus entry and virus-induced cell-to-cell fusion. The cytoplasmic portion of the S glycoprotein contains four cysteine-rich amino acid clusters. Individual cysteine clusters were altered via cysteine-to-alanine amino acid replacement and the modified S glycoproteins were tested for their transport to cell-surfaces and ability to cause cell fusion in transient transfection assays. Mutagenesis of the cysteine cluster I, located immediately proximal to the predicted transmembrane, domain did not appreciably reduce cell-surface expression, although S-mediated cell fusion was reduced by more than 50% in comparison to the wild-type S. Similarly, mutagenesis of the cysteine cluster II located adjacent to cluster I reduced S-mediated cell fusion by more than 60% compared to the wild-type S, while cell-surface expression was reduced by less than 20%. Mutagenesis of cysteine clusters III and IV did not appreciably affect S cell-surface expression or S-mediated cell fusion. The wild-type S was palmitoylated as evidenced by the efficient incorporation of {sup 3}H-palmitic acid in wild-type S molecules. S glycoprotein palmitoylation was significantly reduced for mutant glycoproteins having cluster I and II cysteine changes, but was largely unaffected for cysteine cluster III and IV mutants. These results show that the S cytoplasmic domain is palmitoylated and that palmitoylation of the membrane proximal cysteine clusters I and II may be important for S-mediated cell fusion.

• OSTI ID: 20977007
• Journal Information: Virology, Journal Name: Virology Journal Issue: 2 Vol. 360; ISSN VIRLAX; ISSN 0042-6822
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
ALANINES
CELL MEMBRANES
CYSTEINE
GLYCOPROTEINS
HEXADECANOIC ACID
MUTAGENESIS
MUTANTS
TRITIUM
VIRUSES