1.8.3.6 malfunction fcly mutants of Arabidopsis exhibit reduced S-farnesyl-L-cysteine lyase activity and an enhanced response to abscisic acid 710018 1.8.3.6 malfunction S-(2E,6E)-farnesyl-L-cysteine accumulates in fcly mutants, leading to competitive inhibition of isoprenylcysteine methyltransferase activity, which show enhanced response to abscisic acid reversable by isoprenylcysteine methyltransferase overexpression. The abscisic acid hypersensitive phenotype of fcly plants is the result of farnesyl-L-cysteine accumulation and inhibition of isoprenylcysteine methyltransferase 710018 1.8.3.6 malfunction T-DNA insertions into the FCLY gene cause significant decreases in FC lyase activity and an enhanced response to abscisic acid in seed germination assays. The effects of FCLY mutations on abscisic acid sensitivity are even greater in the presence of exogenous farnesyl-L-cysteine -, 710279 1.8.3.6 metabolism farnesylcysteine lyase is involved in negative regulation of abscisic acid signaling in Arabidopsis. The enzyme is part of an recycling pathway in plants whereby the farnesal product od S-farnesyl-L-cysteine lyase is reduced to farnesol, which is subsequently phosphorylated to farnesyl diphosphate 710018 1.8.3.6 metabolism the enzyme is involved in the salvage cycle for S-(2E,6E)-farnesyl diphosphate in plants, overview 710279 1.8.3.6 physiological function Arabidopsis FC lyase recognizes amide-linked S-(2E,6E)-farnesyl-L-cysteine and may have a role in deprenylation of farnesylated proteins -, 710279 1.8.3.6 physiological function the specific farnesylcysteine lyase is responsible for the oxidative metabolism of FC to farnesal and cysteine 710018