title: A chemical genetic screen uncovers a small molecule enhancer of the N-acylethanolamine degrading enzyme, fatty acid amide hydrolase, in Arabidopsis.
abstract: N-Acylethanolamines (NAEs) are a group of fatty acid amides that play signaling roles in diverse physiological processes in eukaryotes. Fatty acid amide hydrolase (FAAH) degrades NAE into ethanolamine and free fatty acid to terminate its signaling function. In animals, chemical inhibitors of FAAH have been used for therapeutic treatment of pain and as tools to probe deeper into biochemical properties of FAAH. In a chemical genetic screen for small molecules that dampened the inhibitory effect of N-lauroylethanolamine (NAE 12:0) on Arabidopsis thaliana seedling growth, we identified 6-(2-methoxyphenyl)-1,3-dimethyl-5-phenyl-1H-pyrrolo[3,4-d]pyrimidine-2,4(3 H,6 H)-dione (or MDPD). MDPD alleviated the growth inhibitory effects of NAE 12:0, in part by enhancing the enzymatic activity of Arabidopsis FAAH (AtFAAH). In vitro, biochemical assays showed that MDPD enhanced the apparent Vmaxof AtFAAH but did not alter the affinity of AtFAAH for its NAE substrates. Structural analogs of MDPD did not affect AtFAAH activity or dampen the inhibitory effect of NAE 12:0 on seedling growth indicating that MDPD is a specific synthetic chemical activator of AtFAAH. Collectively, our study demonstrates the feasibility of using an unbiased chemical genetic approach to identify new pharmacological tools for manipulating FAAH- and NAE-mediated physiological processes in plants.
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation Inc., Ardmore, OK, 73401, USA.
authors.forename: Bibi Rafeiza
authors.initials: BR
authors.lastname: Khan
authors.affiliation: Center for Plant Lipid Research, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA.|Biology Department, Texas Woman's University, Denton, TX 76204, USA.
authors.forename: Lionel
authors.initials: L
authors.lastname: Faure
authors.affiliation: Center for Plant Lipid Research, Department of Biological Sciences, University of North Texas, Denton, TX 76203, USA.
authors.forename: Kent D
authors.initials: KD
authors.lastname: Chapman
authors.affiliation: Plant Biology Division, The Samuel Roberts Noble Foundation Inc., Ardmore, OK, 73401, USA.
authors.forename: Elison B
authors.initials: EB
authors.lastname: Blancaflor
mesh_terms: D000581:Amidohydrolases / Q000037:antagonists & inhibitors / Q000235:genetics*; D017360:Arabidopsis / Q000187:drug effects / Q000254:growth & development; D004983:Ethanolamines / Q000378:metabolism / Q000494:pharmacology; D007850:Lauric Acids / Q000494:pharmacology; D036226:Seedlings / Q000187:drug effects; D015398:Signal Transduction / Q000187:drug effects* / Q000235:genetics; D054852:Small Molecule Libraries / Q000494:pharmacology*
chemical_list: D004983:Ethanolamines; D007850:Lauric Acids; C022203:N-acylethanolamines; D054852:Small Molecule Libraries; C090359:N-lauroylethanolamine; D000581:Amidohydrolases; C046993:N-acylethanolamine amidohydrolase