9513400 Roth Protein phosphorylation-dephosphorylation events condition the regulation of numerous cellular processes in eukaryotes. However, there are few examples in plant systems that provide a model to dissect the functional significance of a phosphorylation-mediated signal transduction pathway. The long term goal of this research is to characterize the role of the plant encoded double-standed (ds) RNA-dependent protein kinase, pPKR, in uninfected and in virus and viroid infected cells. The primary goals of this renewal are: to extend characterization studies of pPKR and to determine its functional significance with respect to regulation of protein synthesis initiation in tobacco and potato plants. The pPKR is part of a regulatory pathway that may be involved in regulation of protein synthesis, cell division and differentiation, and defense against viral infection. Therefore, it is important to understand the role of this protein in plants.
