The OVERALL OBJECTIVE of the proposed investigation is to elucidate the role of interferon-regulated protein kinase(s) in the actions which natural and recombinant interferons mediate on viral and host functions.
The SPECIFIC AIMS of our proposed continuation investigation of protein phosphorylation and interferon (IFN) action are as follows: (1) To continue our characterization of the full-length CDNA of the IFN- regulated, RNA-dependent P1/eIF-2alpha protein kinase. To characterize the activity of the expressed recombinant kinase, both wild type P1 and catalytic and regulatory domain P1 mutants, and to determine the chromosome assignment of the kinase. To utilize the protein P1 KIN CDNA clone, and antibody prepared against the recombinant P1 protein, in studies on the regulation of P1 expression in IFN-treated and virus-infected animal cells: to attempt to obtain expression of P1 CDNA in eukaryotic cells as an approach to structural and functional analyses of P1. (2) To purify the P1 protein expressed from the CDNA clone, and then to characterize the recombinant P1 protein for its ability to catalyze the RNA-dependent autophosphorylation of protein P1 and the subsequent phosphorylation of the alpha subunit of protein synthesis initiation factor EIF-2. To continue our biochemical characterization of P1 with emphasis on the identification of the site(s) of autophosphorylation associated with activation of the kinase; the construction and characterization of mutants in which the putative ser/thr autophosphorylation site(s) have been converted to ala or to asp; the further characterization of the allosteric RNA binding site of protein P1 through the use of 8-azido double-stranded RNA (dsRNA) photoaffinity probes; the construction and characterization of protein P1 mutants in which the candidate RNA binding site domain has been mutated; the further definition of the reovirus s! MRNA structure capable of activating the kinase; and, to attempt to identify proteins present in uninfected or virus-infected human cells which may associate with protein P1, either as substrates or as regulatory proteins. (3) To attempt to stably express wild-type and mutant (ser to ala, ser to asp; lys to arg) forms of the P1 KIN CDNA in cells in culture, and then to examine the P1-expressing cell lines for phenotype and growth properties, and for their ability to support virus replication and protein synthesis. The health relatedness of the proposed research stems from the likelihood that the work may contribute to a better understanding of regulatory mechanisms involving phosphorylation possibly operative in normal cells as well as virus-infected cells, and that the elucidation of the actions of IFN at the molecular level is of immediate importance in view of the potential applications of IFN in the clinic.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI020611-11
Application #
2061276
Study Section
Virology Study Section (VR)
Project Start
1983-12-01
Project End
1997-04-30
Budget Start
1994-05-01
Budget End
1995-04-30
Support Year
11
Fiscal Year
1994
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
Ma, Dzwokai; George, Cyril X; Nomburg, Jason et al. (2017) Upon Infection the Cellular WD Repeat-containing Protein 5 (WDR5) Localizes to Cytoplasmic Inclusion Bodies and Enhances Measles Virus Replication. J Virol :
Kainulainen, Markus; Lau, Simone; Samuel, Charles E et al. (2016) NSs Virulence Factor of Rift Valley Fever Virus Engages the F-Box Proteins FBXW11 and ?-TRCP1 To Degrade the Antiviral Protein Kinase PKR. J Virol 90:6140-7
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
Wu, Chengjun; Bai, Lufeng; Li, Zhiqun et al. (2015) Poor growth of human adenovirus-12 compared to adenovirus-2 correlates with a failure to impair PKR activation during the late phase of infection. Virology 475:120-8
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
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
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

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