title: A RALDH-like enzyme involved in Fusarium verticillioides development.
abstract: Retinaldehyde dehydrogenases (RALDHs) convert retinal to retinoic acid, an important chordate morphogen. Retinal also occurs in some fungi, such as Fusarium and Ustilago spp., evidenced by the presence of rhodopsins and β-carotene cleaving, retinal-forming dioxygenases. Based on the assumption that retinoic acid may also be formed in fungi, we searched the Fusarium protein databases for RALDHs homologs, focusing on Fusarium verticillioides. Using crude lysates of Escherichia coli cells expressing the corresponding cDNAs, we checked the capability of best matches to convert retinal into retinoic acid in vitro. Thereby, we identified an aldehyde dehydrogenase, termed CarY, as a retinoic acid-forming enzyme, an activity that was also exerted by purified CarY. Targeted mutation of the carY gene in F. verticillioides resulted in alterations of mycelia development and conidia morphology in agar cultures, and reduced capacity to produce perithecia as a female in sexual crosses. Complementation of the mutant with a wild-type carY allele demonstrated that these alterations are caused by the lackof CarY. However, retinoic acid could not be detected by LC-MS analysis either in the wild type or the complemented carY strain in vivo, making elusive the connection between CarY enzymatic activity and retinoic acid formation in the fungus.
authors.affiliation: Department of Genetics, Faculty of Biology, University of Seville, E-41012 Seville, Spain.
authors.forename: Violeta
authors.initials: V
authors.lastname: Díaz-Sánchez
authors.affiliation: Department of Genetics, Faculty of Biology, University of Seville, E-41012 Seville, Spain.
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Limón
authors.affiliation: Faculty of Biology, Albert-Ludwigs University of Freiburg, Schaenzlestr. 1, D-79104 Freiburg, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Schaub
authors.affiliation: Center for Desert Agriculture, BESE Division, King Abdullah University of Science and Technology (KAUST), 23955-6900 Thuwal, Saudi Arabia.
authors.forename: Salim
authors.initials: S
authors.lastname: Al-Babili
authors.affiliation: Department of Genetics, Faculty of Biology, University of Seville, E-41012 Seville, Spain. Electronic address: avalos@us.es.
authors.forename: Javier
authors.initials: J
authors.lastname: Avalos
mesh_terms: D000444:Aldehyde Dehydrogenase / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D000595:Amino Acid Sequence; D002338:Carotenoids / Q000096:biosynthesis; D005656:Fungal Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D005670:Fusarium / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D050697:Retinal Dehydrogenase / Q000737:chemistry; D014212:Tretinoin / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D002338:Carotenoids; D014212:Tretinoin; D000444:Aldehyde Dehydrogenase; D050697:Retinal Dehydrogenase
keywords: Apocarotenoids; Conidia; Fusarium verticillioides; Hyphal development; RALDH enzyme; Retinoic acid; Sexual fertility