All enveloped viruses exploit the cellular secretory pathway for biosynthesis of their membrane proteins. The best studied enveloped viruses assemble by budding from the plasma membrane, where their membrane proteins accumulate. Assembly of enveloped viruses at intracellular membranes is less well understood, although these viruses must also accumulate their membrane proteins at the budding site. Intracellular assembly of the avian coronavirus infectious bronchitis virus (IBV) in the cis Golgi network will be studied. Coronaviruses are ubiquitous in vertebrates, and in humans cause mild respiratory disease (responsible for about 20 percent of common colds). Coronaviruses are conveniently studied in cell culture systems, and are thus an ideal model for intracellular virus assembly. Understanding the intracellular assembly of enveloped viruses is important because several virus families that cause significant human disease assembly at intracellular membranes. These include Bun yaviridae and Flaviviridae. The long term goals of the proposed experiments are to elucidate the mechanism and advantages of intracellular assembly of enveloped viruses, and to identify unique strategies to interfere with assembly and infection by this subset of viruses. Specifically, the experiments are designed to test the following hypotheses: (1) the IBV RNA 3 proteins (3a, 3b, and E) play important roles in virus assembly and infection; (2) the IBV E protein has an additional function in infected cells to slow membrane traffic, allowing S to accumulate at the budding site and possibly preventing virus antigen presentation to the immune system; and (3) distinct envelope lipids (derived from the cis Golgi network) provide an advantage for the virus during subsequent rounds of infection by promoting fusion with susceptible cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
3R01GM064647-02S2
Application #
6790455
Study Section
Virology Study Section (VR)
Program Officer
Chin, Jean
Project Start
2002-04-01
Project End
2006-03-31
Budget Start
2003-04-01
Budget End
2004-03-31
Support Year
2
Fiscal Year
2003
Total Cost
$53,314
Indirect Cost
Name
Johns Hopkins University
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Pendleton, Amanda R; Machamer, Carolyn E (2008) Generating antibodies to the gene 3 proteins of infectious bronchitis virus. Methods Mol Biol 454:163-89
McBride, Corrin E; Li, Jie; Machamer, Carolyn E (2007) The cytoplasmic tail of the severe acute respiratory syndrome coronavirus spike protein contains a novel endoplasmic reticulum retrieval signal that binds COPI and promotes interaction with membrane protein. J Virol 81:2418-28
Machamer, Carolyn E; Youn, Soonjeon (2006) The transmembrane domain of the infectious bronchitis virus E protein is required for efficient virus release. Adv Exp Med Biol 581:193-8
Pendleton, Amanda R; Machamer, Carolyn E (2006) Differential localization and turnover of infectious bronchitis virus 3b protein in mammalian versus avian cells. Virology 345:337-45
Youn, Soonjeon; Collisson, Ellen W; Machamer, Carolyn E (2006) Transcriptional regulation of RNA3 of infectious bronchitis virus. Adv Exp Med Biol 581:109-12
Pendleton, Amanda R; Machamer, Carolyn E (2005) Infectious bronchitis virus 3a protein localizes to a novel domain of the smooth endoplasmic reticulum. J Virol 79:6142-51
Youn, Soonjeon; Collisson, Ellen W; Machamer, Carolyn E (2005) Contribution of trafficking signals in the cytoplasmic tail of the infectious bronchitis virus spike protein to virus infection. J Virol 79:13209-17
Lontok, Erik; Corse, Emily; Machamer, Carolyn E (2004) Intracellular targeting signals contribute to localization of coronavirus spike proteins near the virus assembly site. J Virol 78:5913-22
Corse, Emily; Machamer, Carolyn E (2003) The cytoplasmic tails of infectious bronchitis virus E and M proteins mediate their interaction. Virology 312:25-34