Research Abstract:
Plants are amazing chemists capable of generating an array of small molecules with different biological effects. The goal of our research is to understand the molecular machinery involved in assembling these compounds. Currently, we are studying the biosynthesis of peptides that protect plants from heavy metal toxicity and environmental stresses using approaches that blend biochemistry, plant biology, and x-ray crystallography. Understanding how plants synthesize these peptides provides a foundation for engineering their production. For example, in Arabidopsis and other plants, phytochelatin synthase (PCS) catalyzes the formation of heavy metal chelating peptides. Recently, we re-engineered PCS using directed evolution methods to improve tolerance to cadmium and are evaluating the effect of expressing the engineered PCS on cadmium tolerance and accumulation in plants. Future work will explore the potential of this engineered system as a bioremediation tool. In a related project, we are examining glutathione biosynthesis in plants. Although glutathione is a key component in a plant’s stress response network, the structural and functional details of the proteins that synthesize it, as well as the potential biochemical mechanisms of their regulation, remain unexplored. Our initial investigations suggest that cellular redox environment regulates a key step in this pathway through a thiol-based switching mechanism. This work may lead to more general models of how redox environment regulates protein function in plants. We are also collaborating with Divergence, Inc. (St. Louis, MO) to mechanistically and structurally characterize new protein targets for the development of compounds targeting parasitic nematodes.
Selected Publications:
Alvarex S, Berla BM, Sheffield J, Cahoon RE, Jez JM, Hicks LM. Comprehensive analysis of the Brassica juncea root proteome in response to cadmium exposure by complementary proteomic approaches. Proteomics 2009 9: 2419-2431.
Kumaran S, Yi H, Krishnan HB, Jez JM. Assembly of the cysteine synthase complex and the regulatory role of protein-protein interactions. J. Biol. Chem. 2009 284:10268-10275.
Yi H, Preuss ML, Jez JM. The devil (and an active jasmonate hormone) are in the details. Nature Chem. Biol. 2009 5:273-274.
Zubieta C, Arkus KAJ, Cahoon RE, Jez JM. A single amino acid change is responsible for evolution of acyltransferase specificity in bacterial methionine biosynthesis. J. Biol. Chem. 2008 283:7561-7567.
Hicks LM, Cahoon RE, Bonner ER, Rivard RS, Sheffield J, Jez JM. Thiol-based regulation of redox-active glutamate-cysteine ligase from Arabidopsis thaliana. Plant Cell 2007 19:2653-2661.
Last Updated: 11/04/2009 |