Calcineurin Is an Antagonist to PKA Protein Phosphorylation Required for Postmating Filamentation and Virulence, While PP2A Is Required for Viability in Ustilago maydis
Calcineurin Is an Antagonist to PKA Protein Phosphorylation Required for Postmating Filamentation and Virulence, While PP2A Is Required for Viability in Ustilago maydis
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DOI：
10.1094/mpmi-22-10-1293
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发表时间：
2009-10-01
影响因子：
3.5
通讯作者：
Gold, Scott E.
中科院分区：
文献类型：
--
作者：
Egan, John D.;Garcia-Pedrajas, Maria D.;Gold, Scott E.
玉米黑粉菌（Ustilago maydis）是一种二型性担子菌，是玉米黑穗病的病原菌。它作为了解丝状真菌的二型性、致病性和交配反应的遗传模型。以往的研究表明，受调控的cAMP依赖性蛋白激酶A（PKA）对丝状菌的生长和致病性的重要性。玉米粉两个蛋白磷酸酶的作用，潜在的拮抗PKA进行了评估。用反向遗传学方法突变了U. maydis被雇用了。CN催化亚基ucn1的突变引起了显着的多芽表型和两个ucn1突变体之间的交配严重减少。ucn 1突变株的致病性也严重降低，甚至在solopathogenic单倍体菌株。重要的是，突变破坏蛋白磷酸化的PKA是上位的ucn1突变，表明ucn1作为一个PKA拮抗磷酸酶的主要作用。遗传和抑制剂研究表明，美国的。玉米PP2A催化亚基基因（upa2）是必需的。
Ustilago maydis is a dimorphic basidiomycete and the causal agent of corn smut disease. It serves as a genetic model for understanding dimorphism, pathogenicity, and mating response in filamentous fungi. Previous studies indicated the importance of regulated cAMP-dependent protein kinase A (PKA) for filamentous growth and pathogenicity in U. maydis. The roles of two protein phosphatases that potentially act antagonistically to PKA were assessed. A reverse genetics approach to mutate the catalytic subunits of calcineurin (CN, protein phosphatase [PP]2B) and PP2A in U. maydis was employed. A mutation in the CN catalytic subunit ucn1 caused a dramatic multiple-budding phenotype and mating between two ucn1 mutants was severely reduced. The pathogenicity of ucn1 mutant strains was also severely reduced, even in a solopathogenic haploid strain. Importantly, mutations disrupting protein phosphorylation by PKA were epistatic to ucn1 mutation, indicating a major role of ucn1 as a PKA antagonistic phosphatase. Genetic and inhibitor studies indicated that the U. maydis PP2A catalytic subunit gene (upa2) was essential.