Abstract

The organization and expression of genes involved in siderophore-mediated iron transport in the corn smut pathogen Ustilago maydis will be examined. The importance of this system to the virulence of the fungus will also be assessed.
The specific aims of this proposal are: (1) to isolate and genetically and biochemically characterize mutants of U. maydis that are defective in the biosynthesis and utilization of the siderophores ferrichrome and ferrichrome A; (2) to develop an efficient gene transfer system for U. maydis; (3) to clone the genes for the production and transport of the siderophores; (4) to study the structure and organization of these genes; (5) to analyze siderophore gene expression; and (6) to assess the role of siderophores in the pathogenicity of U. maydis. These experiments involve natural products chemistry, enzymatic assay, gene cloning, nucleic acid hybridization, restriction mapping, DNA sequencing, in vitro site-specific and deletion mutagenesis, and genetic analysis. Knowledge gained from these studies would provide a fundamental understanding of the biochemistry and molecular biology of iron transport in a eucaryotic system.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM033716-02
Application #
3283660
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1986-09-01
Project End
1990-08-31
Budget Start
1987-09-01
Budget End
1988-08-31
Support Year
2
Fiscal Year
1987
Total Cost
Indirect Cost

  Institution

Name
University of Wisconsin Madison
Department
Type
Earth Sciences/Resources
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715

  Publications

Yuan, W M; Gentil, G D; Budde, A D et al. (2001) Characterization of the Ustilago maydis sid2 gene, encoding a multidomain peptide synthetase in the ferrichrome biosynthetic gene cluster. J Bacteriol 183:4040-51
Leong, S A; Winkelmann, G (1998) Molecular biology of iron transport in fungi. Met Ions Biol Syst 35:147-86
An, Z; Zhao, Q; McEvoy, J et al. (1997) The second finger of Urbs1 is required for iron-mediated repression of sid1 in Ustilago maydis. Proc Natl Acad Sci U S A 94:5882-7
An, Z; Mei, B; Yuan, W M et al. (1997) The distal GATA sequences of the sid1 promoter of Ustilago maydis mediate iron repression of siderophore production and interact directly with Urbs1, a GATA family transcription factor. EMBO J 16:1742-50
An, Z; Farman, M L; Budde, A et al. (1996) New cosmid vectors for library construction, chromosome walking and restriction mapping in filamentous fungi. Gene 176:93-6
Mei, B; Budde, A D; Leong, S A (1993) sid1, a gene initiating siderophore biosynthesis in Ustilago maydis: molecular characterization, regulation by iron, and role in phytopathogenicity. Proc Natl Acad Sci U S A 90:903-7
Voisard, C; Wang, J; McEvoy, J L et al. (1993) urbs1, a gene regulating siderophore biosynthesis in Ustilago maydis, encodes a protein similar to the erythroid transcription factor GATA-1. Mol Cell Biol 13:7091-100
Saville, B J; Leong, S A (1992) The molecular biology of pathogenesis in Ustilago maydis. Genet Eng (N Y) 14:139-62
Froeliger, E H; Leong, S A (1991) The a mating-type alleles of Ustilago maydis are idiomorphs. Gene 100:113-22
Smith, T L; Leong, S A (1990) Isolation and characterization of a Ustilago maydis glyceraldehyde-3-phosphate dehydrogenase-encoding gene. Gene 93:111-7

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