In vivo functional characterization of the SARS-Coronavirus 3a protein in Drosophila.

Abstract

The Severe Acute Respiratory Syndrome-Coronavirus (SARS-CoV) 3a locus encodes a 274 a.a. novel protein, and its expression has been confirmed in SARS patients. To study functional roles of 3a, we established a transgenic fly model for the SARS-CoV 3a gene. Misexpression of 3a in Drosophila caused a dominant rough eye phenotype. Using a specific monoclonal antibody, we demonstrated that the 3a protein displayed a punctate cytoplasmic localization in Drosophila as in SARS-CoV-infected cells. We provide genetic evidence to support that 3a is functionally related to clathrin-mediated endocytosis. We further found that 3a misexpression induces apoptosis, which could be modulated by cellular cytochrome c levels and caspase activity. From a forward genetic screen, 78 dominant 3a modifying loci were recovered and the identity of these modifiers revealed that the severity of the 3a-induced rough eye phenotype depends on multiple cellular processes including gene transcriptional regulation.

• Authors: S L Alan Wong, Yiwei Chen, Chak Ming Chan, C S Michael Chan, Paul K S Chan, Y L Chui, Kwok Pui Fung, Mary M Y Waye, Stephen K W Tsui, H Y Edwin Chan
• Journal: Biochemical and biophysical research communications (Biochem Biophys Res Commun) Vol. 337 Issue 2 Pg. 720-9 (Nov 18 2005) ISSN: 0006-291X [Print] United States
• PMID: 16212942 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 3a protein, SARS-CoV
• Antibodies, Monoclonal
• Clathrin
• Viral Envelope Proteins
• Viral Proteins
• Viroporin Proteins

Topics

• Animals
• Animals, Genetically Modified
• Antibodies, Monoclonal (immunology)
• Clathrin (metabolism)
• Cytoplasm (metabolism)
• Drosophila (genetics)
• Endocytosis
• Gene Transfer Techniques
• Humans
• Phenotype
• Severe acute respiratory syndrome-related coronavirus (genetics)
• Viral Envelope Proteins
• Viral Proteins (genetics, metabolism)
• Viroporin Proteins