Myosin I is required for hypha formation in Candida albicans
Myosin I is required for hypha formation in Candida albicans
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DOI：
10.1128/ec.1.2.213-228.2002
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发表时间：
2002-04-01
期刊：
影响因子：
--
通讯作者：
Whiteway, M
中科院分区：
文献类型：
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作者：
Oberholzer, U;Marcil, A;Whiteway, M
致病酵母菌白色念珠菌在形态上会发生戏剧性的变化，从圆形的酵母细胞变成称为菌丝的长丝状细胞。我们已经克隆了编码白色念珠菌中唯一的肌球蛋白I的CaMYO5基因。CaMYO5两个拷贝缺失的菌株是活的，但在所有测试的菌丝诱导条件下都不能形成菌丝。与野生型菌株相比，该突变体表现出更高的随机萌发频率和皮质肌动蛋白斑块的去极化分布。我们发现，极地萌芽、皮质肌动蛋白斑块的极化定位和菌丝的形成依赖于肌球蛋白I上的一个特定的磷酸化位点，称为“TEDS规则”位点。丝氨酸366到丙氨酸的突变导致零突变表型，而S366D突变，其产物模仿磷酸化的丝氨酸，允许菌丝形成。然而，S366D突变仍然导致萌发细胞中皮质肌动蛋白斑块的去极化分布，与零突变相似。CaMyo5-GFP以及芽端和菌丝顶端的皮质肌动蛋白斑块的定位也依赖于丝氨酸366。有趣的是，表达Camyo5(S366D)的突变体大部分菌丝中的皮质肌动蛋白斑块被去极化，这表明尽管它们的分布取决于肌球蛋白I的定位，但极化的皮质肌动蛋白斑块可能不是菌丝形成所必需的。
The pathogenic yeast Candida albicans can undergo a dramatic change in morphology from round yeast cells to long filamentous cells called hyphae. We have cloned the CaMYO5 gene encoding the only myosin I in C. albicans. A strain with a deletion of both copies of CaMYO5 is viable but cannot form hyphae under all hypha-inducing conditions tested. This mutant exhibits a higher frequency of random budding and a depolarized distribution of cortical actin patches relative to the wild-type strain. We found that polar budding, polarized localization of cortical actin patches, and hypha formation are dependent on a specific phosphorylation site on myosin I, called the "TEDS-rule" site. Mutation of this serine 366 to alanine gives rise to the null mutant phenotype, while a S366D mutation, the product of which mimics a phosphorylated serine, allows hypha formation. However, the S366D mutation still causes a depolarized distribution of cortical actin patches in budding cells, similar to that in the null mutant. The localization of CaMyo5-GFP together with cortical actin patches at the bud and hyphal tips is also dependent on serine 366. Intriguingly, the cortical actin patches in the majority of the hyphae of the mutant expressing Camyo5(S366D) were depolarized, suggesting that although their distribution is dependent on myosin I localization, polarized cortical actin patches may not be required for hypha formation.