title: Dominant gain-of-function mutations in transmembrane domain III of ERS1 and ETR1 suggest a novel role for this domain in regulating the magnitude of ethylene response in Arabidopsis.
abstract: Prior work resulted in identification of an Arabidopsis mutant, eer5-1, with extreme ethylene response in conjunction with failure to induce a subset of ethylene-responsive genes, including AtEBP. EER5, which is a TREX-2 homolog that is part of a nucleoporin complex, functions as part of a cryptic aspect of the ethylene signaling pathway that is required for regulating the magnitude of ethylene response. A suppressor mutagenesis screen was carried out to identify second site mutations that could restore the growth of ethylene-treated eer5-1 to wild-type levels. A dominant gain-of-function mutation in the ethylene receptor ETHYLENE RESPONSE SENSOR 1 (ERS1) was identified, with the ers1-4 mutation being located in transmembrane domain III at a point nearly equivalent to the previously described etr1-2 mutation in the other Arabidopsis subfamily I ethylene receptor, ETHYLENE RESPONSE 1 (ETR1). Although both ers1-4 and etr1-2 partially suppress the ethylene hypersensitivity of eer5-1 and are at least in part REVERSION TO ETHYLENE SENSITIVITY 1 (RTE1)-dependent, ers1-4 was additionally found to restore the expression of AtEBP in ers1-4;eer5-1 etiolated seedlings after ethylene treatment in an EIN3-dependent manner. Our work indicates that ERS1-regulated expression of a subset of ethylene-responsive genes is related to controlling the magnitude of ethylene response, with hyperinduction of these genes correlated with reduced ethylene-dependent growth inhibition.
authors.affiliation: Department of Biochemistry, University of California, Riverside, CA, 92521, USA.
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Deslauriers
authors.affiliation: Department of Biochemistry, University of California, Riverside, CA, 92521, USA.
authors.forename: Ashley A
authors.initials: AA
authors.lastname: Alvarez
authors.affiliation: Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA.
authors.forename: Randy F
authors.initials: RF
authors.lastname: Lacey
authors.affiliation: Department of Biochemistry, Cellular and Molecular Biology, University of Tennessee, Knoxville, TN, 37996, USA.
authors.forename: Brad M
authors.initials: BM
authors.lastname: Binder
authors.affiliation: Department of Biochemistry, University of California, Riverside, CA, 92521, USA.
authors.forename: Paul B
authors.initials: PB
authors.lastname: Larsen
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins; D005030:Ethylenes / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant; D016153:Genes, Suppressor; D008565:Membrane Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D009687:Nuclear Proteins / Q000378:metabolism; D010641:Phenotype; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism; D013329:Structure-Activity Relationship; D013489:Suppression, Genetic; D014157:Transcription Factors / Q000378:metabolism
chemical_list: D000596:Amino Acids; D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C106987:EIN3 protein, Arabidopsis; C517775:ERS1 protein, Arabidopsis; C494590:ETR1 protein, Arabidopsis; D005030:Ethylenes; D008565:Membrane Proteins; D009687:Nuclear Proteins; C525374:RTE1 protein, Arabidopsis; D011956:Receptors, Cell Surface; D014157:Transcription Factors; C036216:ethylene
keywords: Arabidopsis thaliana ethylene-responsive element binding protein (AtEBP); EER5; EIN3; ETHYLENE  RESPONSE 1 (ETR1); ETHYLENE RESPONSE SENSOR 1 (ERS1); REVERSION TO ETHYLENE SENSITIVITY 1 (RTE1); ethylene