Disruption of the sphingolipid Δ8-desaturase gene causes a delay in morphological changes in Candida albicans
Disruption of the sphingolipid Δ8-desaturase gene causes a delay in morphological changes in Candida albicans
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DOI：
10.1099/mic.0.2008/018788-0
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发表时间：
2008-12-01
期刊：
影响因子：
2.8
通讯作者：
Kajiwara, Susumu
中科院分区：
文献类型：
--
作者：
Oura, Takahiro;Kajiwara, Susumu
神经酰胺和糖基神经酰胺，包括去饱和长链碱基，存在于大多数真菌以及动物和植物中。然而，由于芽殖酵母酿酒酵母（Saccharomyces cerevisiae）不能使长链碱基去饱和，因此对这些化合物在真菌中的生理作用知之甚少。为了研究真菌细胞中神经酰胺和葡萄糖神经酰胺长链主链去饱和的必要性，我们已经鉴定并表征了来自致病性酵母白色念珠菌的鞘脂δ（8）-去饱和酶（SLD）基因。C.白色念珠菌SLD同源物导致SLID酶的主要底物（E）-鞘氨醇-4-烯碱的积累。将假丝酵母SLD基因同源物导入这些突变体细胞中导致（4 E，8 E）-鞘氨醇-4，8-二烯碱的合成恢复，因此该基因同源物被鉴定为Ca-SLD基因。此外，C.与野生型菌株相比，白色念珠菌具有降低的菌丝生长速率。这些结果表明，神经酰胺中长链碱基的δ（3）-去饱和在C.白色念珠菌。
Ceramides and glycosylceramides, including desaturated long-chain bases, are present in most fungi as well as animals and plants. However, as the budding yeast Saccharomyces cerevisiae is not capable of desaturating long-chain bases, little is known about the physiological roles of these compounds in fungi. To investigate the necessity of desaturation of long-chain backbones in ceramides and glucosylceramides in fungal cells, we have identified and characterized a sphingolipid Delta(8)-desaturase (SLD) gene from the pathogenic yeast Candida albicans. Gene disruption of the C. albicans SLD homologue led to the accumulation of (E)-sphing-4-enine, a main substrate for the SLID enzyme. Introducing the Candida SLD gene homologue into these mutant cells resulted in the recovery of synthesis of (4E, 8E)-sphinga-4,8-dienine and this gene homologue was therefore identified as a Ca-SLD gene. Additionally, the SO disruptant of C. albicans had a decreased hyphal growth rate compared with the wild-type strain. These results suggest that Delta(3)-desaturation of long-chain bases in ceramides plays a role in the morphogenesis of C. albicans.