title: New insights into the operative network of FaEO, an enone oxidoreductase from Fragaria x ananassa Duch.
abstract: The 2-methylene-furan-3-one reductase or Fragaria x ananassa Enone Oxidoreductase (FaEO) catalyses the last reductive step in the biosynthesis of 4-hydroxy-2,5-dimethyl-3(2H)-furanone, a major component in the characteristic flavour of strawberries. In the present work, we describe the association between FaEO and the vacuolar membrane of strawberry fruits. Even if FaEO lacks epitopes for stable or transient membrane-interactions, it contains a calmodulin-binding region, suggesting that in vivo FaEO may be associated with the membrane via a peripheral protein complex with calmodulin. Moreover, we also found that FaEO occurs in dimeric form in vivo and, as frequently observed for calmodulin-regulated proteins, it may be expressed in different isoforms by alternative gene splicing. Further mass spectrometry analysis confirmed that the isolated FaEO consists in the already known isoform and that it is the most characteristic during ripening. Finally, a characterization by absorption spectroscopy showed that FaEO has specific flavoprotein features. The relevance of these findings and their possible physiological implications are discussed.
authors.affiliation: Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, V.le S. Ignazio da Laconi 13, 09123, Cagliari, Italy.
authors.forename: Gabriella
authors.initials: G
authors.lastname: Collu
authors.affiliation: Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, V.le S. Ignazio da Laconi 13, 09123, Cagliari, Italy.|Department of Molecular Sensory Systems, Center of Advanced European Studies and Research (caesar), Ludwig-Erhard-Allee 2, 52175, Bonn, Germany.
authors.forename: Domenica
authors.initials: D
authors.lastname: Farci
authors.affiliation: Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria, 09042, Monserrato, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Esposito
authors.affiliation: Department of Life and Environmental Sciences, University of Cagliari, Cittadella Universitaria, 09042, Monserrato, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Pintus
authors.affiliation: Leibniz Institute on Aging - Fritz Lipmann Institute, Beutebergstraβe 11, 07745, Jena, Germany.
authors.forename: Joanna
authors.initials: J
authors.lastname: Kirkpatrick
authors.affiliation: Laboratory of Plant Physiology and Photobiology, Department of Life and Environmental Sciences, University of Cagliari, V.le S. Ignazio da Laconi 13, 09123, Cagliari, Italy. dario.piano@unica.it.
authors.forename: Dario
authors.initials: D
authors.lastname: Piano
mesh_terms: D017398:Alternative Splicing / Q000502:physiology; D001483:Base Sequence; D018744:DNA, Plant / Q000235:genetics; D031985:Fragaria / Q000201:enzymology* / Q000235:genetics*; D005638:Fruit / Q000201:enzymology / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000502:physiology*; D053858:Metabolic Networks and Pathways / Q000502:physiology; D008958:Models, Molecular; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D011487:Protein Conformation; D020033:Protein Isoforms
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins; D020033:Protein Isoforms; D010088:Oxidoreductases
keywords: 2-Methylene-furan-3-one reductase; 4-Hydroxy-2,5-dimethyl-3(2H)-furanone; Alternative splicing; Calmodulin; Fragaria x ananassa enone oxidoreductase; Strawberry