title: Structural reorganization of the fungal endoplasmic reticulum upon induction of mycotoxin biosynthesis.
abstract: Compartmentalization of metabolic pathways to particular organelles is a hallmark of eukaryotic cells. Knowledge of the development of organelles and attendant pathways under different metabolic states has been advanced by live cell imaging and organelle specific analysis. Nevertheless, relatively few studies have addressed the cellular localization of pathways for synthesis of fungal secondary metabolites, despite their importance as bioactive compounds with significance to medicine and agriculture. When triggered to produce sesquiterpene (trichothecene) mycotoxins, the endoplasmic reticulum (ER) of the phytopathogenic fungus Fusarium graminearum is reorganized both in vitro and in planta. Trichothecene biosynthetic enzymes accumulate in organized smooth ER with pronounced expansion at perinuclear- and peripheral positions. Fluorescence tagged trichothecene biosynthetic proteins co-localize with the modified ER as confirmed by co-fluorescence and co-purification with known ER proteins. We hypothesize that changes to the fungal ER represent a conserved process in specialized eukaryotic cells such as in mammalian hepatocytes and B-cells.
authors.affiliation: Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul, MN 55108, USA.
authors.forename: Marike Johanne
authors.initials: MJ
authors.lastname: Boenisch
authors.affiliation: USDA ARS Cereal Disease Laboratory, St. Paul, MN 55108, USA.
authors.forename: Karen Lisa
authors.initials: KL
authors.lastname: Broz
authors.affiliation: Pacific Northwest National Laboratory, Richland, WA 99354 USA.
authors.forename: Samuel Owen
authors.initials: SO
authors.lastname: Purvine
authors.affiliation: Pacific Northwest National Laboratory, Richland, WA 99354 USA.
authors.forename: William Byron
authors.initials: WB
authors.lastname: Chrisler
authors.affiliation: Pacific Northwest National Laboratory, Richland, WA 99354 USA.
authors.forename: Carrie Diana
authors.initials: CD
authors.lastname: Nicora
authors.affiliation: Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Lanelle Reine
authors.initials: LR
authors.lastname: Connolly
authors.affiliation: Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Freitag
authors.affiliation: Pacific Northwest National Laboratory, Richland, WA 99354 USA.
authors.forename: Scott Edward
authors.initials: SE
authors.lastname: Baker
authors.affiliation: USDA ARS Cereal Disease Laboratory, St. Paul, MN 55108, USA.|Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108, USA.
authors.forename: Harold Corby
authors.initials: HC
authors.lastname: Kistler
mesh_terms: D053898:Biosynthetic Pathways / Q000235:genetics; D004721:Endoplasmic Reticulum / Q000378:metabolism* / Q000648:ultrastructure; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005670:Fusarium / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D009183:Mycotoxins / Q000096:biosynthesis*; D010935:Plant Diseases / Q000382:microbiology; D064210:Secondary Metabolism / Q000235:genetics; D014255:Trichothecenes / Q000096:biosynthesis*; D014908:Triticum / Q000382:microbiology
chemical_list: D005656:Fungal Proteins; D008164:Luminescent Proteins; D009183:Mycotoxins; D014255:Trichothecenes