title: The ukb1 gene encodes a putative protein kinase required for bud site selection and pathogenicity in Ustilago maydis.
abstract: Morphogenesis and pathogenesis are closely associated aspects of the life cycle of the fungal pathogen Ustilago maydis. In this fungus, the dimorphic switch from budding to filamentous growth coincides with the transition from non-pathogenic to pathogenic growth on maize. We have cloned and characterized the ukb1 gene that encodes a putative serine/threonine protein kinase with a role in budding and filamentous growth. Mutants defective in ukb1 were altered in bud site selection and produced lateral buds at a greater frequency than wild-type cells. Dikaryotic cells defective in ukb1 were capable of colonizing host tissue and growing with a filamentous morphology in planta. However, the mutants were incapable of inducing tumor formation and they failed to complete sexual development. In addition, the ukb1 gene influenced the ability of colonies to form aerial mycelia in response to environmental stimuli. Overall, the discovery of ukb1 reinforces the connection between morphogenesis and pathogenesis in U. maydis.
authors.affiliation: Biotechnology Laboratory, Department of Microbiology and Immunology, Faculty of Agricultural Sciences, University of British Columbia, 237-6174 University Blvd., Vancouver, BC, Canada.
authors.forename: R B
authors.initials: RB
authors.lastname: Abramovitch
authors.forename: G
authors.initials: G
authors.lastname: Yang
authors.forename: J W
authors.initials: JW
authors.lastname: Kronstad
mesh_terms: D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D004271:DNA, Fungal; D005800:Genes, Fungal / Q000502:physiology*; D008969:Molecular Sequence Data; D009024:Morphogenesis; D010641:Phenotype; D011494:Protein Kinases / Q000235:genetics / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D014588:Ustilago / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity
chemical_list: D004271:DNA, Fungal; D011494:Protein Kinases