Our goal is to gain insight into the functions of protein phosphatase 2A (PP2A), an enzyme that performs important roles in phosphorylation circuits governing growth, morphogenesis and cell fate.

The DeLong laboratory uses molecular and genetic approaches to gain insight into the mechanisms that control plant growth and development. Many signaling pathways involve reversible protein phosphorylation events that regulate key steps in development, as well as responses to the environment. The activities of protein phosphatases make important contributions to the regulatory circuitry controlling plant biology, and it is clear that protein phosphatase activities themselves are tightly regulated. We have used the model plant Arabidopsis thaliana to define circuits regulated by the protein phosphatase 2A (PP2A) family, a versatile hub for cellular signaling that achieves specificity through combinatorial complexity. Our previous work identified roles of PP2A including regulation of polar auxin transport, embryogenesis and reproductive development.

Our current work focuses on defining phosphorylation-mediated switches that control synthesis of the signaling molecule ethylene. Ethylene synthesis and response are conserved throughout land plants, and ethylene signaling is used to cue stress and defense responses as well as major developmental transitions via tightly controlled pathways. We are also using functional genomics and genome engineering approaches to isolate new PP2A mutants, to identify additional signal transduction and growth control roles of PP2A.

We recently used phylogenetic analyses to reconstruct the evolutionary histories of PP2A gene families. These analyses revealed that while whole-genome duplications have driven expansion of PP2A gene families, distinct subclades exhibit reduced rates of expansion and may perform specialized functions.

1989-1992 National Science Foundation Postdoctoral Fellowship
1982-1985 National Science Foundation Graduate Fellowship
1982 Phi Beta Kappa

American Society of Plant Biologists