Protein Modification and Turnover
Huizinga, David , Deem, Angela , Trobaugh, Corey , Denton, Ryan , Sen, Stephanie , Crowell, Dring .
Farnesylcysteine lyase in Arabidopsis thaliana.
In plants, prenylated proteins are involved in actin organization, calcium-mediated signal transduction, and many other biological processes. Arabidopsis thaliana mutants lacking functional protein prenyltransferase genes have also revealed roles for prenylated proteins in phytohormone signaling and meristem development. However, to date, the turnover of prenylated plant proteins and the fate of the prenylcysteine (PC) residue have not been described. We have detected an enzyme activity in Arabidopsis plants that metabolizes farnesylcysteine (FC) to farnesal, which is subsequently reduced to farnesol. Unlike its mammalian ortholog, Arabidopsis FC lyase exhibits specificity for FC over geranylgeranylcysteine (GGC) and recognizes N-acetyl-FC. FC lyase is encoded by a gene on chromosome 5 of the Arabidopsis genome (FCLY, At5g63910) and is ubiquitously expressed in Arabidopsis tissues and organs. Furthermore, T-DNA insertions into the FCLY gene cause significant decreases in FC lyase activity and enhanced responses to abscisic acid (ABA) in seed germination and stomatal closure assays. The effects of fcly mutations on ABA sensitivity are even greater in the presence of exogenous FC. These data suggest that plants possess a specific FC detoxification and recycling pathway.
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1 - Indiana University - Purdue University Indianapolis, Department of Biology, 723 West Michigan Street, Indianapolis, IN, 46202, USA
2 - Indiana University - Purdue University Indianapolis, Department of Biology
3 - Indiana University - Purdue University Indianapolis, Department of Chemistry and Chemical Biology
Presentation Type: Plant Biology Abstract
Location: Exhibit Hall (Northeast, Southwest & Southeast)/Hilton
Date: Sunday, July 8th, 2007
Time: 8:00 AM