Association of a myosin immunoanalogue with cell envelopes of Aspergillus fumigatus conidia and its participation in swelling and germination
Association of a myosin immunoanalogue with cell envelopes of Aspergillus fumigatus conidia and its participation in swelling and germination
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DOI：
10.1128/iai.67.3.1238-1244.1999
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发表时间：
1999-03-01
影响因子：
3.1
通讯作者：
Tronchin, G
中科院分区：
文献类型：
--
作者：
Esnault, K;El Moudni, B;Tronchin, G
用两种不同的抗肌球蛋白抗体，通过Western印迹、间接免疫荧光试验和金免疫电镜，在烟曲霉分生孢子中鉴定出一种肌球蛋白免疫类似物。这种蛋白质的分布模式，随后在萌发的早期阶段。一个主要存在于细胞膜提取物中的180-kDa多肽，与脊椎动物肌球蛋白的单克隆抗体和多克隆抗体发生交叉反应。免疫电镜对该多肽进行了精确的定位，表明肌球蛋白类似物主要分布在休眠和膨胀的分生孢子的质膜上。间接免疫荧光显微镜显示，在芽管周围有肌球蛋白类似物，而肌动蛋白则在芽管的细胞质中呈分散的点状结构。在芽管出现的部位更为集中。一种肌球蛋白ATP酶抑制剂丁二酮单肟，大大减少了肿胀和阻止发芽。相反，当分生孢子用细胞松弛素B（一种肌动蛋白聚合的抑制剂）处理时，肿胀不受影响，萌发仅部分减少。丁二酮单肟处理的分生孢子表现出细胞质囊泡的积累，并没有实现细胞壁重组，不像肿胀的分生孢子。总的来说，这些结果表明，这种肌球蛋白类似物在萌发过程中细胞壁成分的沉积中起着重要作用。烟曲霉分生孢子，因此在寄主组织中定殖。
A myosin immunoanalogue was identified in conidia of Aspergillus fumigatus by Western blotting, indirect immunofluorescence assay, and gold immunoelectron microscopy with two different antimyosin antibodies. The distribution pattern of this protein was followed during the early stages of germination. A single 180-kDa polypeptide, detected predominantly in a cell envelope extract, was found to cross-react with monoclonal and polyclonal antibodies raised against vertebrate muscle myosin, Immunoelectron microscopy permitted precise localization of this polypeptide, indicating that myosin analogue was mainly distributed along the plasma membrane of resting and swollen conidia, In germinating conidia, indirect immunofluorescence microscopy revealed myosin analogue at the periphery of germ tubes, whereas actin appeared as dispersed punctate structures in the cytoplasm that. were more concentrated at the site of germ tube emergence. A myosin ATPase inhibitor, butanedione monoxime, greatly reduced swelling and blocked germination. In contrast, when conidia were treated with cytochalasin B, an inhibitor of actin polymerization, swelling was not affected and germination was only partially reduced. Butanedione monoxime-treated conidia showed accumulation of cytoplasmic vesicles and did not achieve cell wall reorganization, unlike swollen conidia, Collectively, these results suggest an essential role for this myosin analogue in the deposition of cell wall components during germination of A. fumigatus conidia and therefore In host tissue colonization.