Abstract

Understanding of the mechanisms by which nonenveloped viruses penetrate membrane bilayers during entry into cells may provide targets for novel antiviral strategies, and may also be useful for designing safer and more effective vaccine, gene-delivery and/or anti-tumor agents derived from these viruses. Mammalian orthoreoviruses are unique model systems for understanding mechanisms and regulation of membrane penetration by nonenveloped viruses. The current proposal is centered on the structures and cell-entry functions of the virion-associated outer capsid proteins mu-1, sigma-3 and sigma-1.
The specific aims of the proposal are to: (1) determine the steps in outer-capsid assembly, (2) determine the steps in outer-capsid disassembly as they relate to cell entry, and determine how the mu-1 protein effects virus penetration through the cell membrane, (3) identify structural features of the outer capsid proteins as relates to their assembly and functions in entry. The proposed studies are made possible because progress has been made in re-coating subvirion particles with outer coat proteins in vitro, thereby recovering particle infectivity. These in vitro recoating methods have been adapted into a new style of molecular genetic analysis of reovirus outer-capsid structure and function by using mutant forms of recombinant proteins for recoating.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI046440-04
Application #
6698574
Study Section
Virology Study Section (VR)
Program Officer
Challberg, Mark D
Project Start
2001-01-01
Project End
2005-12-31
Budget Start
2004-01-01
Budget End
2004-12-31
Support Year
4
Fiscal Year
2004
Total Cost
$360,486
Indirect Cost

  Institution

Name
Harvard University
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
047006379
City
Boston
State
MA
Country
United States
Zip Code
02115

  Publications

Yan, Xiaodong; Parent, Kristin N; Goodman, Russell P et al. (2011) Virion structure of baboon reovirus, a fusogenic orthoreovirus that lacks an adhesion fiber. J Virol 85:7483-95
Zhang, Lan; Agosto, Melina A; Ivanovic, Tijana et al. (2009) Requirements for the formation of membrane pores by the reovirus myristoylated micro1N peptide. J Virol 83:7004-14
Tang, Jinghua; Ochoa, Wendy F; Sinkovits, Robert S et al. (2008) Infectious myonecrosis virus has a totivirus-like, 120-subunit capsid, but with fiber complexes at the fivefold axes. Proc Natl Acad Sci U S A 105:17526-31
Ivanovic, Tijana; Agosto, Melina A; Zhang, Lan et al. (2008) Peptides released from reovirus outer capsid form membrane pores that recruit virus particles. EMBO J 27:1289-98
Agosto, Melina A; Myers, Kimberly S; Ivanovic, Tijana et al. (2008) A positive-feedback mechanism promotes reovirus particle conversion to the intermediate associated with membrane penetration. Proc Natl Acad Sci U S A 105:10571-6
Middleton, Jason K; Agosto, Melina A; Severson, Tonya F et al. (2007) Thermostabilizing mutations in reovirus outer-capsid protein mu1 selected by heat inactivation of infectious subvirion particles. Virology 361:412-25
Ivanovic, Tijana; Agosto, Melina A; Chandran, Kartik et al. (2007) A role for molecular chaperone Hsc70 in reovirus outer capsid disassembly. J Biol Chem 282:12210-9
Agosto, Melina A; Middleton, Jason K; Freimont, Elaine C et al. (2007) Thermolabilizing pseudoreversions in reovirus outer-capsid protein micro 1 rescue the entry defect conferred by a thermostabilizing mutation. J Virol 81:7400-9
Agosto, Melina A; Ivanovic, Tijana; Nibert, Max L (2006) Mammalian reovirus, a nonfusogenic nonenveloped virus, forms size-selective pores in a model membrane. Proc Natl Acad Sci U S A 103:16496-501
Coffey, Caroline M; Sheh, Alexander; Kim, Irene S et al. (2006) Reovirus outer capsid protein micro1 induces apoptosis and associates with lipid droplets, endoplasmic reticulum, and mitochondria. J Virol 80:8422-38

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