36:	Arabidopsis thaliana farnesylated, metal-binding proteins are regulated during reproductive development.

Authors:	Dykema, Philip , E.(A)
Affiliations:	(A): Indiana University - Purdue University at Indianapolis
Presenter:	Dykema, Philip E., pdykema@iupui.edu

Reproductive organs in Arabidopsis thaliana are nutrient sinks, accumulating both organic compounds and inorganic elements. Intracellular concentrations of certain transition metal ions are carefully regulated in eukaryotic cells through selective membrane and intracellular transport mechanisms as well as sequestration. We recently identified a unique group of Arabidopsis cDNAs encoding proteins which are isoprenylated and which have the capacity to bind specific transition metal ions. These genes are expressed predominately during the reproductive phase of the life cycle in Arabidopsis thaliana var. Columbia. Moreover, the accumulation patterns of the corresponding mRNAs are influenced by levels of available transition metal ions. Stringent hybridization of genomic DNA Southern blots demonstrates a unique pattern for each gene. We are currently developing model systems to test our current working model that these isoprenylated, metal-binding plant proteins participate in intracellular metal ion homeostasis by sequestering and/or transporting specific transition metal ions.