9604782 DeLong Reversible protein phosphorylation plays a crucial role in the control of cellular processes that govern growth, development and interaction with the environment. The protein kinases and phosphatase establishing a pattern of phosphorylation and dephosphorylation must be tightly controlled through their presence and activity. The work focuses on the protein phosphatase 2A family in Arabidopsis and utilizes yeast mutants in the catalytic and regulatory subunits of PP2A to isolate the plant homologs. The potential usefulness of this yeast complementation approach has been documented in preliminary data. Building on this success the work will characterize the plant PP2A and use transgenic plants to affect the amount, location, and activity of PP2A in whole plants. The results, considering that very little information is available for plants, are expected to shed light on the multitude of PP2A isoforms and their various functions at the cellular, tissue and whole plant levels.
