title: Arabidopsis sensitivity to protein synthesis inhibitors depends on 26S proteasome activity.
abstract: The 26S proteasome (26SP), the central protease of the ubiquitin-dependent proteolysis pathway, controls the regulated proteolysis of functional proteins and the removal of misfolded and damaged proteins. In Arabidopsis, cellular and stress response phenotypes of a number of mutants with partially impaired 26SP function have been reported. Here, we describe the responses of proteasome mutants to protein synthesis inhibitors. We show that the rpt2a-3, rpn10-1 and rpn12a-1 mutants are hypersensitive to the antibiotic hygromycin B, and tolerant to the translation inhibitor cycloheximide (CHX) and herbicide L-phosphinothricin (PPT). In addition to the novel mechanism for herbicide tolerance, our data suggests that the combination of hygromycin B, CHX and PPT growth-response assays could be used as a facile diagnostic tool to detect altered 26SP function in plant mutants and transgenic lines.
authors.affiliation: Plant Physiology, Biochemistry, Molecular Biology Program, Department of Plant and Soil Sciences, College of Agriculture, University of Kentucky, 1401 University Drive, Lexington, KY 40546-0236, USA.
authors.forename: Jasmina
authors.initials: J
authors.lastname: Kurepa
authors.forename: Consolée
authors.initials: C
authors.lastname: Karangwa
authors.forename: Liliana Sfichi
authors.initials: LS
authors.lastname: Duke
authors.forename: Jan A
authors.initials: JA
authors.lastname: Smalle
mesh_terms: D000613:Aminobutyrates / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D003513:Cycloheximide / Q000494:pharmacology; D018525:Germination / Q000187:drug effects; D006540:Herbicides / Q000494:pharmacology; D006921:Hygromycin B / Q000494:pharmacology; D009154:Mutation; D046988:Proteasome Endopeptidase Complex / Q000235:genetics*; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology*
chemical_list: D000613:Aminobutyrates; D006540:Herbicides; D011500:Protein Synthesis Inhibitors; D006921:Hygromycin B; C003121:phosphinothricin; D003513:Cycloheximide; D046988:Proteasome Endopeptidase Complex; C061553:ATP dependent 26S protease