PlantsP Project

Protein phosphorylation and dephosphorylation are fundamental to cellular regulation. These post-translational modifications, which are catalyzed by protein kinases and phosphatases, constitute a reversible molecular switch. In plants protein phosphorylation has been implicated in the control of most developmental events and environmental responses including governance of the cell cycle, transcriptional and translational regulation, control of carbon and nitrogen metabolism, regulation of growth and differentiation, and responses to abiotic and biotic environmental cues.

The breadth of cellular processes regulated by protein kinases is reflected in the genomes of plants. Currently it is estimated that nearly 1000 genes encode proteins belonging to the eukaryotic protein kinase superfamily in Arabidopsis thaliana. An additional 300 genes encode protein phosphatases. Furthermore, at least 50 members of two-component systems are predicted to be present in Arabidopsis (e.g. histidine kinases and response regulators).

Because protein kinases and phosphatases control so many processes in plants, and occur in networks that unite different cellular processes, a genome wide approach is needed to make significant advances in discovering the roles of these enzymes in the regulation of plant function.