The long term objective of this proposal is to determine how poliovirus (PV) inhibits initiation of host cell RNA synthesis by RNA polymerases I, II and III. The pol Il factor, TFIID which interacts with the TATA box promotors, the pol I factor, TFIIIC which interacts with the internal promotor elements of tRNA genes, and a poll factor involved in promotor recognition (upstream binding factor, UBF) are inactivated soon after PV infection. Biochemical and genetic evidence suggests that a virus-encoded proteinase, 3CPro is directly involved in host cell transcription shut-off 3CPro specifically cleaves the TATA-binding protein, TBP (a component of TFIID), TFIIIC and an yet unidentified poll factor. Additionally, some factors such as TFIIIC and a pol II factor CREB (cyclic AMP-responsive element binding protein) are dephosphorylated in infected cells. Thus both proteolysis and dephosphorylation contribute to host cell transcription shut-off. Biochemical, serological and genetic approaches will be used to determine the mechanism(s) of inactivation of TBP, TFIIIC, UBF and CREB in virus- infected cells. Specifically, we will determine how TBP cleavage by 3CPro leads to inactivation of TBP. We will determine whether truncated TBP interacts with other general transcription factors or TBP-associated proteins (TAFs). Whether a mutant TBP, which is resistant to cleavage by 3CPro, is susceptible to transcription shut-off will be examined. We will also determine whether a mutant poliovirus defective in 3CPro function is defective in shutting-off pol II transcription and if expression of 3CPro gene in HeLa cells leads to transcription shut-off. The mechanism of dephosphorylation of CREB will be examined by using both biochemical and serological techniques. Biochemical and serological techniques will be used to examine the nature of the polypeptide(s) cleaved by 3CPro in TFIIIC. Genetic, biochemical and serological techniques will be used to identify the pol I factor affected in virus-infected cells and to study the mechanism of inactivation of its transcriptional activity. Since the TATA binding protein has recently been shown to be involved in pol I and pol III transcription, we will determine whether cleavage of TBP by 3CPro contributes to pol III and pol I transcription shut-off using genetic and biochemical means. Elucidation of the mechanism by which poliovirus negatively affects cellular transcription factor activities would undoubtedly facilitate a better understanding of regulation of transcription in eukaryotic cells as well as virus-host interactions in general.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI027451-10
Application #
2653806
Study Section
Virology Study Section (VR)
Project Start
1989-02-01
Project End
1999-01-31
Budget Start
1998-02-01
Budget End
1999-01-31
Support Year
10
Fiscal Year
1998
Total Cost
Indirect Cost
Name
University of California Los Angeles
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Banerjee, Rajeev; Weidman, Mary K; Navarro, Sonia et al. (2005) Modifications of both selectivity factor and upstream binding factor contribute to poliovirus-mediated inhibition of RNA polymerase I transcription. J Gen Virol 86:2315-22
Jhaveri, Ravi; Kundu, Pallob; Shapiro, Alan M et al. (2005) Effect of heptitis C virus core protein on cellular gene expression: specific inhibition of cyclooxygenase 2. J Infect Dis 191:1498-506
Kundu, Pallob; Raychaudhuri, Santanu; Tsai, Weimin et al. (2005) Shutoff of RNA polymerase II transcription by poliovirus involves 3C protease-mediated cleavage of the TATA-binding protein at an alternative site: incomplete shutoff of transcription interferes with efficient viral replication. J Virol 79:9702-13
Banerjee, Rajeev; Weidman, Mary K; Echeverri, Angela et al. (2004) Regulation of poliovirus 3C protease by the 2C polypeptide. J Virol 78:9243-56
Sharma, Rakhi; Raychaudhuri, Santanu; Dasgupta, Asim (2004) Nuclear entry of poliovirus protease-polymerase precursor 3CD: implications for host cell transcription shut-off. Virology 320:195-205
Weidman, Mary K; Sharma, Rahki; Raychaudhuri, Santanu et al. (2003) The interaction of cytoplasmic RNA viruses with the nucleus. Virus Res 95:75-85
Banerjee, R; Dasgupta, A (2001) Interaction of picornavirus 2C polypeptide with the viral negative-strand RNA. J Gen Virol 82:2621-7
Banerjee, R; Tsai, W; Kim, W et al. (2001) Interaction of poliovirus-encoded 2C/2BC polypeptides with the 3' terminus negative-strand cloverleaf requires an intact stem-loop b. Virology 280:41-51
Weidman, M K; Yalamanchili, P; Ng, B et al. (2001) Poliovirus 3C protease-mediated degradation of transcriptional activator p53 requires a cellular activity. Virology 291:260-71
Banerjee, R; Dasgupta, A (2001) Specific interaction of hepatitis C virus protease/helicase NS3 with the 3'-terminal sequences of viral positive- and negative-strand RNA. J Virol 75:1708-21

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