We are studying the mechanism whereby viruses enter their host cells and initiate replication. The virus systems to be studied are Semliki Forest virus (SFV) and Influenza A virus, which have proven relevant model systems for the general problems of early virus-cell interactions. The overall aim is to define on molecular and cellular terms the following steps in entry: internalization of the virus particles by endocytosis, penetration from endosomes by membrane fusion, uncoating of the genome, and transport to the cytoplasmic or nuclear location of replication and transcription. We hope to obtain a deeper understanding of the principles underlying viral pathogenicity and cell tropism as well as of basic biological phenomena such as membrane fusion, nuclear targeting and the interaction between cellular compartments. The specific aspects include a more detailed definition of endocytic organelles where acid-triggered fusion of the viruses takes place. The conformational changes in the viral fusion proteins acid-induced, activity will be characterized in detail with emphasis on the sterol dependence of SFV (now recognized as a common property among viruses) and the interaction between the fusion factors and the fusing membranes. The mechanism of action of the trimeric hemagglutinin, the fusion factor of Influenza virus, will be studied using hybrid molecules made up of trimers consisting of different subunits. The fate of the nucleocapsids after penetration will be followed by biochemical and immunochemical methods. We will, moreover, try to resolve the signals which induce uncoating of the genome and analyze the molecular mechanism by which uncoating takes place, the transport of the genome to the SFV-specific cytopathic vacuols, and Influenza to the nucleus, will be investigated. A variety of methods ranging from immunocytochemistry on frozen sections to bulk delivery of anti-sense oligonucleotides will be used.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37AI018599-13
Application #
2060731
Study Section
Special Emphasis Panel (NSS)
Project Start
1982-01-01
Project End
1996-12-31
Budget Start
1994-01-01
Budget End
1994-12-31
Support Year
13
Fiscal Year
1994
Total Cost
Indirect Cost
Name
Yale University
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
082359691
City
New Haven
State
CT
Country
United States
Zip Code
06520
Ojala, P M; Sodeik, B; Ebersold, M W et al. (2000) Herpes simplex virus type 1 entry into host cells: reconstitution of capsid binding and uncoating at the nuclear pore complex in vitro. Mol Cell Biol 20:4922-31
Bui, M; Wills, E G; Helenius, A et al. (2000) Role of the influenza virus M1 protein in nuclear export of viral ribonucleoproteins. J Virol 74:1781-6
Alconada, A; Bauer, U; Sodeik, B et al. (1999) Intracellular traffic of herpes simplex virus glycoprotein gE: characterization of the sorting signals required for its trans-Golgi network localization. J Virol 73:377-87
Kann, M; Sodeik, B; Vlachou, A et al. (1999) Phosphorylation-dependent binding of hepatitis B virus core particles to the nuclear pore complex. J Cell Biol 145:45-55
Whittaker, G R; Helenius, A (1998) Nuclear import and export of viruses and virus genomes. Virology 246:1-23
Sodeik, B; Ebersold, M W; Helenius, A (1997) Microtubule-mediated transport of incoming herpes simplex virus 1 capsids to the nucleus. J Cell Biol 136:1007-21
Bui, M; Whittaker, G; Helenius, A (1996) Effect of M1 protein and low pH on nuclear transport of influenza virus ribonucleoproteins. J Virol 70:8391-401
Whittaker, G; Bui, M; Helenius, A (1996) Nuclear trafficking of influenza virus ribonuleoproteins in heterokaryons. J Virol 70:2743-56
Whittaker, G; Kemler, I; Helenius, A (1995) Hyperphosphorylation of mutant influenza virus matrix protein, M1, causes its retention in the nucleus. J Virol 69:439-45
Kemler, I; Whittaker, G; Helenius, A (1994) Nuclear import of microinjected influenza virus ribonucleoproteins. Virology 202:1028-33

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