ibclogo XVI International Botanical Congess


Abstract Number: 6019
Session = 21.11.4


REGULATION OF PROTEIN FUNCTION AND LOCALIZATION BY POST-TRANSITIONAL ISOPRENYLATION


Dring N. Crowell & Stephen K. Randall, Department of Biology, Indiana University - Purdue University at Indianapolis, Indianapolis, IN 46202-5132


The targeting and function of many eukaryotic proteins is governedby the covalent attachment of an isoprenoid moiety to a cysteine residue at or near the carboxyl terminus of the protein. In plant cells, as in animal and yeast cells, three distinct prenyl:protein transferases modify specific target proteins by catalyzing the formation of a thioether bond to either a fifteen carbon farnesyl or a twenty carbon geranylgeranyl moiety. This modification is often followed by other post-translational processing steps, including alpha-carboxyl methylation of carboxyl terminal prenylcysteine residues. Recent data from various laboratories indicate that isoprenylated plant proteins are involved in ABA signaling and cell cycle control. To further address the functions of isoprenylated plant proteins, we have identified prenyl:protein transferase substrates by in vitro prenylation of recombinant proteins expressed in three different plant cDNA expression libraries. Results from our laboratories suggest that isoprenylated proteins are involved in many diverse processes in plant cells, including vesicle transport, defense responses, and transition metal homeostasis.


HTML-Version made 7. July 1999 by Kurt Stüber