title: Arabidopsis thaliana plants possess a specific farnesylcysteine lyase that is involved in detoxification and recycling of farnesylcysteine.
abstract: 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 (AFC). 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 an enhanced response to abscisic acid (ABA) in seed germination 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.
authors.affiliation: Department of Biology, Indiana University - Purdue University Indianapolis, 723 West Michigan Street, Indianapolis, IN 46202-5132, USA. dcrowell@inpui.edu
authors.forename: Dring N
authors.initials: DN
authors.lastname: Crowell
authors.forename: David H
authors.initials: DH
authors.lastname: Huizinga
authors.forename: Angela K
authors.initials: AK
authors.lastname: Deem
authors.forename: Corey
authors.initials: C
authors.lastname: Trobaugh
authors.forename: Ryan
authors.initials: R
authors.lastname: Denton
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Sen
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000378:metabolism*; D013437:Carbon-Sulfur Lyases / Q000378:metabolism*; D003545:Cysteine / Q000031:analogs & derivatives* / Q000378:metabolism*; D018744:DNA, Plant / Q000235:genetics; D005204:Farnesol / Q000378:metabolism*; D008658:Inactivation, Metabolic; D007700:Kinetics; D008969:Molecular Sequence Data; D011496:Protein Methyltransferases / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D029681:Arabidopsis Proteins; D018744:DNA, Plant; D005204:Farnesol; C057785:S-farnesylcysteine; D011496:Protein Methyltransferases; C056501:protein-S-isoprenylcysteine O-methyltransferase; D013437:Carbon-Sulfur Lyases; C523450:farnesylcysteine lyase, Arabidopsis; D003545:Cysteine