title: Cycloheximide as a tool to investigate protein import in peroxisomes: a case study of the subcellular localization of isoprenoid biosynthetic enzymes.
abstract: Cytosolic background fluorescence is often observed when native low-abundance peroxisomal proteins carrying a weak peroxisomal targeting sequence are expressed as fluorescent fusion protein using a strong constitutive promoter in transiently transformed plant cells. This cytosolic fluorescence usually comes from the strong expression of the low-abundance proteins exceeding the peroxisome import efficiency. This often results in a misinterpretation of the protein subcellular localization, as there is doubt as to whether proteins are dually targeted to the cytosol and peroxisome or are exclusively localized to peroxisomes. To circumvent this experimental difficulty, the protein peroxisome import study can be optimized by de novo protein synthesis inhibition in transiently transformed cells using the translation inhibitor cycloheximide. This approach was used here successfully for the study of the subcellular localization of distinct plant isoprenoid biosynthetic enzymes, allowing us to clearly demonstrate that 5-phosphomevalonate kinase, mevalonate 5-diphosphate decarboxylase and a short isoform of farnesyl diphosphate synthase from Catharanthus roseus are exclusively localized to peroxisomes.
authors.affiliation: Université François-Rabelais de Tours, EA 2106 Biomolécules et Biotechnologies Végétales, 37200 Tours, France.
authors.forename: Grégory
authors.initials: G
authors.lastname: Guirimand
authors.forename: Andrew John
authors.initials: AJ
authors.lastname: Simkin
authors.forename: Nicolas
authors.initials: N
authors.lastname: Papon
authors.forename: Sébastien
authors.initials: S
authors.lastname: Besseau
authors.forename: Vincent
authors.initials: V
authors.lastname: Burlat
authors.forename: Benoit
authors.initials: B
authors.lastname: St-Pierre
authors.forename: Nathalie
authors.initials: N
authors.lastname: Giglioli-Guivarc'h
authors.forename: Marc
authors.initials: M
authors.lastname: Clastre
authors.forename: Vincent
authors.initials: V
authors.lastname: Courdavault
mesh_terms: D002262:Carboxy-Lyases / Q000378:metabolism; D030008:Catharanthus / Q000166:cytology / Q000201:enzymology*; D002478:Cells, Cultured; D003513:Cycloheximide / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D051228:Geranyltranstransferase / Q000378:metabolism; D020675:Peroxisomes / Q000201:enzymology*; D017856:Phosphotransferases (Phosphate Group Acceptor) / Q000378:metabolism; D010937:Plant Growth Regulators / Q000378:metabolism; D010940:Plant Proteins / Q000096:biosynthesis; D030821:Plants, Genetically Modified / Q000201:enzymology; D021381:Protein Transport / Q000502:physiology*; D013729:Terpenes / Q000378:metabolism*
chemical_list: D010937:Plant Growth Regulators; D010940:Plant Proteins; D013729:Terpenes; D003513:Cycloheximide; D051228:Geranyltranstransferase; D017856:Phosphotransferases (Phosphate Group Acceptor); C022371:phosphomevalonate kinase; D002262:Carboxy-Lyases; C022503:pyrophosphomevalonate decarboxylase