Parta M, Chang Y, Rulong S, Pinto-DaSilva P, Kwon-Chung K J
Clinical Mycology Section, National Institute of Allergy and Infectious Diseases, NIH, Bethesda, MD 20892.
Infect Immun. 1994 Oct;62(10):4389-95. doi: 10.1128/iai.62.10.4389-4395.1994.
Aspergillus fumigatus produces conidia that are highly dispersable and resistant to degradation. We have sought to analyze these properties by studying the rodlets which form the outer spore coat protein. Degenerate primers based on hydrophobins in other fungi were applied to genomic DNA from A. fumigatus in PCR. A product of this reaction with similarity to an Aspergillus nidulans gene as judged by Southern hybridization was chosen for further study. Cloning and sequencing revealed a gene with two introns which encodes a protein of 159 amino acids. Structural characteristics consistent with those of other fungal hydrophobin genes, especially conserved cysteine residues, are present. The expression of the gene is limited to the developmental stages in which maturing conidiophores are present. This A. fumigatus gene, HYP1, was used to transform a mutant strain of A. nidulans that lacks rodlets. Transformants with a single copy of HYP1 expressed a rodlet layer on their conidia as observed by freeze-fracture electron microscopy.
烟曲霉产生的分生孢子具有高度分散性且抗降解。我们试图通过研究构成外孢子壁蛋白的小杆来分析这些特性。基于其他真菌中疏水蛋白的简并引物被应用于烟曲霉的基因组DNA进行PCR。通过Southern杂交判断，该反应的一个与构巢曲霉基因相似的产物被选作进一步研究。克隆和测序揭示了一个有两个内含子的基因，其编码一个159个氨基酸的蛋白质。存在与其他真菌疏水蛋白基因一致的结构特征，尤其是保守的半胱氨酸残基。该基因的表达仅限于存在成熟分生孢子梗的发育阶段。这个烟曲霉基因HYP1被用于转化一个缺乏小杆的构巢曲霉突变菌株。通过冷冻断裂电子显微镜观察，带有单拷贝HYP1的转化体在其分生孢子上表达了一层小杆。
