Asim Dasgupta, Ph.D.

Work Address:
CHS
Los Angeles, CA 90095 43-144 CHS
CAMPUS - 174718
CA CHS
Los Angeles, CA 90095

Affiliations
Affiliations
Professor, Microbiology, Immunology & Molecular Genetics
Member, Basic/Translational Research, Jonsson Comprehensive Cancer Center, JCCC Signal Transduction and Therapeutics Program Area
Research Interests
Our laboratory is studying the molecular biology of small mammalian RNA viruses. These viruses called picornaviruses include those inducing common cold (rhinoviruses), poliomyelitis, (poliovirus), infectious hepatitis (hepatitis A), encephalitis and juvenile diabetes (coxsackie viruses) and many other animal and plant viruses. We are interested in the mechanisms by which these viruses (i) negatively regulated host cell transcription by RNA polymerases I, II and III. (ii) replicate their RNA genome and (iii) regulate host cell mRNA translation. Currently, cell-free systems are available in our laboratory in which to study these processes. We have democtrated that a virus-coded protease specifically cleaves cellular TATA-box binding transcription factor, TBP and other Pol I and Pol III sequence-specific DNA-binding factors to bring about inhibition of host cell transcription. We also have identified a host cell protein which is required for the replication of viral RNA. Very recently we have discovered a unique small RNA molecule from the yeast Saccharomyces cerevisiae which specifically inhibits viral RNA translation without affecting cellular protein synthesis. Studies are presently underway to evaluate this molecule as a potential antiviral drug.
Biography

Asim Dasgupta is a virologist and molecular biologist who has served on the UCLA School of Medicine faculty since he joined the Department of Microbiology, Immunology and Molecular Genetics in 1981. He became a full professor in 1989 and has served as Graduate advisor for the department from 1984 to 1995. He also served as the Vice-Chairman of the department from 1992-1995. Dr. Dasgupta earned his B.S. in Chemistry and M.S. Biochemistry from Calcutta University, India, followed by a Ph.D. degree in Chemistry/Biochemistry from the University of Nebraska-Lincoln. He was a postdoctoral fellow at the Massachusetts Institutes of Technology, where he worked on RNA virus replication in the laboratory of Dr. David Baltimore. Dr. Dasgupta received the prestigious American Cancer Society Faculty Research award as well as the NIH Career Development Award. His laboratory research centers on RNA virus replication as well as transcriptional and translational control in cells infected with mammalian RNA viruses such as poliovirus, rhinovirus and hepatitis C virus (HCV). In 1994, Dr. Dasgupta’s laboratory discovered a natural antiviral molecule from the yeast S. cerevisiae, which was shown to specifically block internal ribosome entry site (IRES)-mediated translation of viral RNAs. Currently a major focus of his laboratory has been to design molecules that specifically interfere with HCV genome translation and replication.

Publications
Jhaveri R, Kundu P, Shapiro AM, Venkatesan A, Dasgupta A Effect of heptitis C virus core protein on cellular gene expression: specific inhibition of cyclooxygenase 2. The Journal of infectious diseases. . 2005; 191(9): 1498-506.
Banerjee R, Weidman MK, Navaro S, Comai L, Dasgupta A Modifications of both the selectivity factor (SL-1) and upstream binding factor (UBF) contribute to poliovirus-mediated shut-off host cell RNA polymerase I transcription. Virology 2005; 86: 2315-2322.
Kundu P, Raychaudhuri S, Tsai W, Dasgupta A RNA polymerase II transcription shut-off by poliovirus 3C protease involves cleavage of the TATA binding protein at an alternative site: incomplete transcription shut-off interferes with efficient viral replication. J. Virology 2005; 79: 9702-9713.
Izumi RE, Das S, Barat B, Raychaudhuri S, Dasgupta A A peptide from autoantigen La blocks poliovirus and hepatitis C virus cap-independent translation and reveals a single tyrosine critical for La RNA binding and translation stimulation. Journal of virology. . 2004; 78(7): 3763-76.
Sharma R, Raychaudhuri S, Dasgupta A Nuclear entry of poliovirus protease-polymerase precursor 3CD: implications for host cell transcription shut-off. Virology. . 2004; 320(2): 195-205.
Banerjee R, Weidman MK, Echeverri A, Kundu P, Dasgupta A Regulation of poliovirus 3C protease by the 2C polypeptide. Journal of virology. . 2004; 78(17): 9243-56.
Dasgupta A Targeting TFIIH to inhibit host cell transcription by Rift Valley Fever Virus. Molecular cell. . 2004; 13(4): 456-8.
Dasgupta A, Das S, Izumi R, Venkatesan A, Barat B Targeting internal ribosome entry site (IRES)-mediated translation to block hepatitis C and other RNA viruses. FEMS microbiology letters. . 2004; 234(2): 189-99.
Venkatesan A, Sharma R, Dasgupta A Cell cycle regulation of hepatitis C and encephalomyocarditis virus internal ribosome entry site-mediated translation in human embryonic kidney 293 cells. Virus research. . 2003; 94(2): 85-95.
Weidman MK, Sharma R, Raychaudhuri S, Kundu P, Tsai W, Dasgupta A The interaction of cytoplasmic RNA viruses with the nucleus. Virus Res. 2003; 95(1-2): 75-85.
Venkatesan A, Dasgupta A Novel fluorescence-based screen to identify small synthetic internal ribosome entry site elements. Molecular and cellular biology. . 2001; 21(8): 2826-37.
Dasgupta A, et al Effect of picornavirus proteases on host cell transcription. In Picornaviruses (Eds. E. Wimmer and B. Semler), ASM press 2002; 321-336.
Venkatesan A, Dasgupta A Novel fluorescence-based screen to identify small synthetic internal ribosome entry site elements. Molecular and cellular biology. . 2001; 21(8): 2826-37.
Banerjee R, Dasgupta A Interaction of picornavirus 2C polypeptide with the viral negative-strand RNA. The Journal of general virology. . 2001; 82(Pt 11): 2621-7.
Banerjee R, Tsai W, Kim W, Dasgupta A Interaction of poliovirus-encoded 2C/2BC polypeptides with the 3' terminus negative-strand cloverleaf requires an intact stem-loop b. Virology. . 2001; 280(1): 41-51.
Izumi R, Valdez B, Banerjee R, Srivatava M, Dasgupta A Nucleolin stimulates internal ribosome entry site-mediaed translation. Virus Research 2001; Volume 76: 17-29.
Weidman K, Yalamanchili P, Ng B, Tsai W, Dasgupta A Poliovirus 3C-mediated degradation of transcriptional activator p53 requires a cellular activity. Virology 2001; Volume 291: 260-271.
Banerjee R, Dasgupta A Specific interaction of hepatitis C virus protease/helicase NS3 with the 3'ends of viral plus and minus strand RNA. Journal of Virology 2001; Volume 75: 1708-1721.
Banerjee R, Igo M, Izumi R, Datta U, Dasgupta A In Vitro Replication of RNA Viruses. RNA viruses 2000; Practical approach (Ed. Alan J. Cann): 141-178.
Das S, Ott M, Yamane A, Venkatesan A, Gupta S, Dasgupta A Inhibition of internal entry site-mediated translation by a small yeast RNA : A novel strategy to block Hepatitis C virus protein synthesis. Frontiers in Bioscience 1999; Vol 3, d1241-1252: .
Venkatesan A, Das A, Dasgupta A Structure & function of a small RNA that selectively inhibits internal ribosome entry site-mediated translation. Nucl. Acid Res 1999; Vol 27, No 2: 562-572.
Das S, Ott M, Yamane A, Tsai W, Gromeier M, Lahser F, Gupta S, Dasgupta A A small yeast RNA blocks hepatitis C virus internal ribosome entry site (HCV IRES)-mediated translation and inhibits replication of a chimeric poliovirus under translational control of the HCV IRES element. Journal of virology. . 1998; 72(7): 5638-47.
Echeverri A, Banerjee R, Dasgupta A Amino-terminal region of poliovirus 2C protein is sufficient for membrane binding. Virus research. . 1998; 54(2): 217-23.
Yalamanchili P, Weidman K, Dasgupta A Cleavage of transcriptional activator Oct-1 by poliovirus encoded protease 3Cpro. Virology. . 1997; 239(1): 176-85.
Banerjee R, Echeverri A, Dasgupta A Poliovirus-encoded 2C polypeptide specifically binds to the 3'-terminal sequences of viral negative-strand RNA. Journal of virology. . 1997; 71(12): 9570-8.