title: Hxt1, a monosaccharide transporter and sensor required for virulence of the maize pathogen Ustilago maydis.
abstract: The smut Ustilago maydis, a ubiquitous pest of corn, is highly adapted to its host to parasitize on its organic carbon sources. We have identified a hexose transporter, Hxt1, as important for fungal development during both the saprophytic and the pathogenic stage of the fungus. Hxt1 was characterized as a high-affinity transporter for glucose, fructose, and mannose; ∆hxt1 strains show significantly reduced growth on these substrates, setting Hxt1 as the main hexose transporter during saprophytic growth. After plant infection, ∆hxt1 strains show decreased symptom development. However, expression of a Hxt1 protein with a mutation leading to constitutively active signaling in the yeast glucose sensors Snf3p and Rgt2p results in completely apathogenic strains. Fungal development is stalled immediately after plant penetration, implying a dual function of Hxt1 as transporter and sensor. As glucose sensors are only known for yeasts, 'transceptor' as Hxt1 may constitute a general mechanism for sensing of glucose in fungi. In U. maydis, Hxt1 links a nutrient-dependent environmental signal to the developmental program during pathogenic development.
authors: Department of Genetics, Institute of Applied Biosciences, Karlsruhe Institute of Technology, Hertzstrasse 16, Karlsruhe, 76187, Germany.
authors: David
authors: D
authors: Schuler
authors: Department of Genetics, Institute of Applied Biosciences, Karlsruhe Institute of Technology, Hertzstrasse 16, Karlsruhe, 76187, Germany.
authors: Ramon
authors: R
authors: Wahl
authors: Molecular Plant Physiology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstrasse 5, Erlangen, 91058, Germany.
authors: Kathrin
authors: K
authors: Wippel
authors: Department of Genetics, Institute of Applied Biosciences, Karlsruhe Institute of Technology, Hertzstrasse 16, Karlsruhe, 76187, Germany.
authors: Miroslav
authors: M
authors: Vranes
authors: Institute of Bioinformatics and Systems Biology, Helmholtz Center Munich, Ingolstädter Landstraße 1, Neuherberg, 85764, Germany.
authors: Martin
authors: M
authors: Münsterkötter
authors: Molecular Plant Physiology, Friedrich Alexander University Erlangen-Nuremberg, Staudtstrasse 5, Erlangen, 91058, Germany.
authors: Norbert
authors: N
authors: Sauer
authors: Department of Genetics, Institute of Applied Biosciences, Karlsruhe Institute of Technology, Hertzstrasse 16, Karlsruhe, 76187, Germany.
authors: Jörg
authors: J
authors: Kämper
mesh_terms: D019943:Amino Acid Substitution; D005632:Fructose / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005947:Glucose / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015398:Signal Transduction; D014588:Ustilago / Q000235:genetics / Q000378:metabolism / Q000472:pathogenicity*; D037521:Virulence Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D003313:Zea mays / Q000382:microbiology*
chemical_list: D005656:Fungal Proteins; D009004:Monosaccharide Transport Proteins; D037521:Virulence Factors; D005632:Fructose; D005947:Glucose
keywords: Ustilago maydis; biotrophic development; monosaccharide sensor; monosaccharide transport; plant pathogen; transceptor