Sho1 and Msb2-Related Proteins Regulate Appressorium Development in the Smut Fungus Ustilago maydis
Sho1 and Msb2-Related Proteins Regulate Appressorium Development in the Smut Fungus Ustilago maydis
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DOI：
10.1105/tpc.109.073734
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发表时间：
2010-06-01
期刊：
影响因子：
11.6
通讯作者：
Kahmann, Regine
中科院分区：
文献类型：
--
作者：
Lanver, Daniel;Mendoza-Mendoza, Artemio;Kahmann, Regine
玉米黑粉菌在植物表面由出芽转变为菌丝生长。针对疏水性和羟基脂肪酸，U。玉米会形成一种叫做附着胞的感染结构。在这里，我们报告说，不像在酿酒酵母和其他真菌Sho 1（合成的高渗透压敏感）和Msb 2（多拷贝抑制芽缺陷）调节应激反应和假菌丝生长，Sho 1和Msb 2样蛋白在U.玉米粉Sho 1通过双杂交筛选被鉴定为促分裂原活化蛋白（MAP）激酶Kpp 6的相互作用伴侣。上位性分析表明，sho 1和msb 2的MAP激酶KPP 2和KPP 6的上游行为。此外，Sho 1显示通过与Kpp 6中独特的N-末端结构域直接相互作用使Kpp 6不稳定，表明Sho 1在微调Kpp 6活性中的作用。响应于疏水表面的形态分化在sho 1 msb 2突变体中强烈减弱，而羟基脂肪酸诱导的分化不受影响。这些数据表明Sho 1和跨膜粘蛋白Msb 2参与了U.玉米粉
The dimorphic fungus Ustilago maydis switches from budding to hyphal growth on the plant surface. In response to hydrophobicity and hydroxy fatty acids, U. maydis develops infection structures called appressoria. Here, we report that, unlike in Saccharomyces cerevisiae and other fungi where Sho1 (synthetic high osmolarity sensitive) and Msb2 (multicopy suppressor of a budding defect) regulate stress responses and pseudohyphal growth, Sho1 and Msb2-like proteins play a key role during appressorium differentiation in U. maydis. Sho1 was identified through a two-hybrid screen as an interaction partner of the mitogen-activated protein (MAP) kinase Kpp6. Epistasis analysis revealed that sho1 and msb2 act upstream of the MAP kinases kpp2 and kpp6. Furthermore, Sho1 was shown to destabilize Kpp6 through direct interaction with the unique N-terminal domain in Kpp6, indicating a role of Sho1 in fine-tuning Kpp6 activity. Morphological differentiation in response to a hydrophobic surface was strongly attenuated in sho1 msb2 mutants, while hydroxy fatty acid-induced differentiation was unaffected. These data suggest that Sho1 and the transmembrane mucin Msb2 are involved in plant surface sensing in U. maydis.