Tea1, a kelch domain protein, is required for cell morphogenesis in Ustilago maydis

Ustilago maydis is a basidiomycete fungus known to cause tumor formation in maize. It exhibits two distinct forms: yeast-like and filamentous. Both forms exhibit cell polarity, an inherent process observed in all cell types. In the Ascomycota, Tea1 homologs are involved in cell morphogenesis. Tea1 homologs had not been identified in the Basidiomycota. In this study, I have characterized the homolog of the Schizosaccharomyces pombe tea1 gene in U. maydis. I have determined the Δ tea1 null phenotype through a gene deletion strategy, established the subcellular localization of Tea1 and Tea4 using GFP fusions, and determined a Tea1 interaction with itself using a yeast two-hybrid approach. These studies provide support for a major role of Tea1 in cell morphogenesis, in maintaining an axis of polarized growth, and in cell polarity in U. maydis