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Nilgun Tumer
Professor
Rutgers University
Dept. of Plant Pathology
Biotechnology Center for Agriculture and the Environment
208B Foran Hall
School of Env & Biol Sciences
59 Dudley Road
New Brunswick. NJ 08901-8520
(848) 932-6359
FAX - 6535
tumer@aesop.rutgers.edu |
Viral replication and virus resistance in transgenic plants
Major focus of the research in our laboratory is studying the mechanism by
which ribosome inactivating proteins (RIPs) inhibit cellular translation and
viral infection. Pokeweed antiviral protein (PAP). a ribosome inactivating
protein from Phytolacca americana inhibits translation by catalytically
removing a specific adenine residue from the large rRNA of the 60S subunit of
eukaryotic ribosomes. In addition to its ribosome inactivating ability. PAP has
potent activity against many plant and animal viruses including HIV. PAP has
been targeted to cancer cells as the cytotoxic moiety of immunotoxins and has
shown significant clinical antileukemic activity. Our research involves
understanding the mechanism of cytotoxicity and antiviral activity of PAP. We
have demonstrated that expression of PAP in transgenic plants leads to broad
spectrum virus resistance. We investigated the mechanism of cytotoxicity of PAP
and demonstrated that cytotoxicity is not solely due to enzymatic activity. but
appears to involve different domains of the protein. We expressed several
non-toxic PAP mutants in transgenic plants and demonstrated that antiviral
activity of PAP can be separated from its cytotoxicity. We recently showed that
PAP inhibits frameshifting and retrotransposition of Ty1 in yeast and identified
yeast chromosomal mutants that are resistant to PAP. Our current research
focuses on characterizing these host genes and determining their role in
ribosome depurination and virus resistance.
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