The overall objective of the proposed research is to elucidate in molecular terms the mechanisms by which purified natural and cloned human leukocyte (IFN-alpha) and immune (IFN-gamma) interferons act to affect a wide variety of fundamental viral and cellular processes.
The specific aims are as follows: (1) To elucidate the structure function of polypeptide p54, a protein efficiently induced by IFN-gamma in human cells, but poorly, if at all, induced by IFN-alpha. Biochemical and immunological characterizations suggest that p54 may be a cytoskeleton-associated polypeptide. We plan to attempt to obtain a molecular clone of p54 and to use the clone and antibody as reagents to elucidate the function of p54 and its possible role in the antiviral effects of IFN-gamma. (2) To attempt to elucidate, by combined molecular genetic and biochemical approach, the molecular basis of the antiviral effects of human IFN-alpha exerted at the level of protein synthesis. Reovirus and vesicular stomatitis virus are inhibited by IFN-alpha in several cell lines at the level of mRNA translation. The expression of cDNA copies of reovirus and VSV genes is likewise inhibited by IFN-alpha, but not IFN-gamma, in transfected simian cells at the level of protein synthesis. We plan to construct mutant reovirus cDNA expression vectors, and to study the effect of IFN on reovirus protein synthesis in transfected cells. (3) To continue our efforts to determine the biochemical basis, both in vitro and in vivo, of the difference in translational efficiency of the s-class mRNAs of reovirus. The rate of synthesis of the individual omega-class polypeptides differs significantly under conditions where the molar amount of the four sigma-class mRNAs differs by less than 2-fold. To attempt to identify the RNA binding domains of polypeptides omega NS and omega 3, and the function of polypeptide p12, products of reovirus class genes. The health relatedness of the proposed research stems from the likelihood that the work may contribute to a better understanding of regulatory mechanisms possibly operative in normal cells as well as virus-infected cells, and that the elucidation the molecular mechanisms of action of the different types of interferons is of immediate important in view of the potential application of IFN in the clinic.

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 #
5R37AI012520-21
Application #
2059892
Study Section
Special Emphasis Panel (NSS)
Project Start
1978-05-01
Project End
1999-01-31
Budget Start
1995-02-01
Budget End
1996-01-31
Support Year
21
Fiscal Year
1995
Total Cost
Indirect Cost
Name
University of California Santa Barbara
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
City
Santa Barbara
State
CA
Country
United States
Zip Code
93106
George, Cyril X; Ramaswami, Gokul; Li, Jin Billy et al. (2016) Editing of Cellular Self-RNAs by Adenosine Deaminase ADAR1 Suppresses Innate Immune Stress Responses. J Biol Chem 291:6158-68
George, Cyril X; Samuel, Charles E (2015) STAT2-dependent induction of RNA adenosine deaminase ADAR1 by type I interferon differs between mouse and human cells in the requirement for STAT1. Virology 485:363-70
Pfaller, Christian K; Mastorakos, George M; Matchett, William E et al. (2015) Measles Virus Defective Interfering RNAs Are Generated Frequently and Early in the Absence of C Protein and Can Be Destabilized by Adenosine Deaminase Acting on RNA-1-Like Hypermutations. J Virol 89:7735-47
Pfaller, Christian K; Radeke, Monte J; Cattaneo, Roberto et al. (2014) Measles virus C protein impairs production of defective copyback double-stranded viral RNA and activation of protein kinase R. J Virol 88:456-68
John, Lijo; Samuel, Charles E (2014) Induction of stress granules by interferon and down-regulation by the cellular RNA adenosine deaminase ADAR1. Virology 454-455:299-310
Taghavi, Nora; Samuel, Charles E (2013) RNA-dependent protein kinase PKR and the Z-DNA binding orthologue PKZ differ in their capacity to mediate initiation factor eIF2?-dependent inhibition of protein synthesis and virus-induced stress granule formation. Virology 443:48-58
Okonski, Kristina M; Samuel, Charles E (2013) Stress granule formation induced by measles virus is protein kinase PKR dependent and impaired by RNA adenosine deaminase ADAR1. J Virol 87:756-66
Ruggieri, Alessia; Dazert, Eva; Metz, Philippe et al. (2012) Dynamic oscillation of translation and stress granule formation mark the cellular response to virus infection. Cell Host Microbe 12:71-85
Taghavi, Nora; Samuel, Charles E (2012) Protein kinase PKR catalytic activity is required for the PKR-dependent activation of mitogen-activated protein kinases and amplification of interferon beta induction following virus infection. Virology 427:208-16
Samuel, Charles E (2012) ADARs: viruses and innate immunity. Curr Top Microbiol Immunol 353:163-95

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