Identification of fuz7, a Ustilago maydis MEK/MAPKK homolog required for a-locus-dependent and -independent steps in the fungal life cycle.
- 15 June 1994
- journal article
- research article
- Published by Cold Spring Harbor Laboratory in Genes & Development
- Vol. 8 (12), 1367-1378
- https://doi.org/10.1101/gad.8.12.1367
Abstract
Ustilago maydis is a plant pathogenic Basidiomycete fungus that exhibits dimorphism--it has a haploid, yeast-like phase and a dikaryotic, filamentous phase that is pathogenic. Establishment and maintenance of these two forms are controlled by two mating type loci, a and b. The a locus is thought to govern fusion of haploid cells to form a dikaryon and is also required for filamentous growth of the dikaryon. It encodes two components of a pheromone response pathway: pheromones and receptors. We report the identification of the U. maydis fuz7 gene, which codes for a putative dual specificity serine/threonine tyrosine kinase of the MAP kinase kinase (MAPKK/MEK) family, by homology with other members of the family. Analysis of mutants deleted for fuz7 shows that it participates in different facets of the life cycle: It is necessary for a-locus-dependent processes, such as conjugation tube formation, filament formation, and maintenance of filamentous growth, and for a-locus-independent processes, such as tumor induction and teliospore germination. fuz7 is the first U. maydis gene distinct from the b locus required for fungal pathogenicity. We propose that fuz7 is involved in at least two pathways, one of which responds to the pheromones coded by the a locus and the other to putative signals from the plant.Keywords
This publication has 30 references indexed in Scilit:
- Morphological Transitions in the Life Cycle of Ustilago maydis and Their Genetic Control by the a and b LociExperimental Mycology, 1994
- Prokaryotic plant parasitesCell, 1993
- The MAP kinase cascade is essential for diverse signal transduction pathwaysTrends in Biochemical Sciences, 1993
- An Osmosensing Signal Transduction Pathway in YeastScience, 1993
- Ustilago maydis, the delightful blightTrends in Genetics, 1992
- The a mating type locus of U. maydis specifies cell signaling componentsCell, 1992
- Signal Transduction During Pheromone Response in YeastAnnual Review of Cell Biology, 1991
- The Protein Kinase Family: Conserved Features and Deduced Phylogeny of the Catalytic DomainsScience, 1988
- Mutants of Saccharomyces cerevisiae unresponsive to cell division control by polypeptide mating hormone.The Journal of cell biology, 1980
- Saccharomyces cerevisiae : A Diffusible Sex FactorScience, 1970