Thomas Jefferson Fellow Professor Emeritus
Department of Biochemistry
Metabolism, signal transduction, protein kinases and phosphorylated proteins in plants.
Our group is studying regulation of metabolism in plants, in particular, the pyruvate dehydrogenase complex as a primary site at which photosynthetic carbon metabolism interacts with mitochondrial respiration and photorespiration. The regulation of this multienzyme complex has several layers including covalent modification by reversible phosphorylation (inactivation/deactivation). The regulation of the pyruvate dehydrogenase complex provides a site to manage the flow of carbon to the mitochondria during photosynthesis. Another form of this multienzyme complex is located in plastids where it functions in fatty acid and oil biosynthesis by providing the precursor acetyl-CoA for fatty acid, oil synthesis and a number of plant growth regulatory compounds.
Related projects include the molecular characterization of the component subunits of the pyruvate dehydrogenase complex and how these subunits are imported into the organelle and assembled into the complex. We are also charcterizing plant protein kinases and identifying their endogenous substrates. Protein kinases are essential components of many signal transduction pathways. Our group is part of a multi-institutional genomics project involving plant protein phosphorylation. We have projects involving three types of proteins kinase in three different subcellular components. Involvement in the plant protein phosphorylation genomics project is opening new ways of discovering regulatory mechanisms.