Serine/threonine protein phosphatase is required for tobacco mosaic virus-mediated programmed cell death.
A major gap in our understanding of host response to virus infection is how the molecular signals are passed within infected cells. Tobacco mosaic virus-mediated programmed cell death in genotype NN tobaccos was used to evaluate the hypothesis that these molecular signals are transduced via reversible-protein phosphorylation. Nicotiana tabacum L. (genotype NN) confers a hypersensitive response at the site of virus infection when incubated at a permissive temperature. Activation of serine/threonine protein phosphatase correlated with the temperature-dependent induction of the death program. The serine/threonine protein phosphatase inhibitor okadaic acid inhibited the onset and extent of the hypersensitive response in vivo. Biochemical analysis indicates that protein phosphatase type 1 is activated early in the death program. This is the first indication that serine/threonine protein phosphatase is required in an early event of the host response to virus infection.
Dunigan
D D
DD
Department of Biology-LIF 136, University of South Florida, Tampa 33620-5150.
Madlener
J C
JC
D017209:Apoptosis / Q000187:drug effects / Q000502:physiology; D004988:Ethers, Cyclic / Q000494:pharmacology; D017343:Genes, Plant; D019319:Okadaic Acid; D010749:Phosphoprotein Phosphatases / Q000378:metabolism*; D010766:Phosphorylation; D010940:Plant Proteins / Q000378:metabolism; D010947:Plants, Toxic; D015398:Signal Transduction; D014026:Nicotiana / Q000166:cytology / Q000235:genetics / Q000821:virology; D014027:Tobacco Mosaic Virus / Q000201:enzymology* / Q000472:pathogenicity / Q000502:physiology
D004988:Ethers, Cyclic; D010940:Plant Proteins; D019319:Okadaic Acid; D010749:Phosphoprotein Phosphatases