Sakuradani Eiji, Murata Shoichi, Kanamaru Hiroyuki, Shimizu Sakayu
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kitashirakawa-oiwakecho, Sakyo-ku, Kyoto, 606-8502, Japan.
Appl Microbiol Biotechnol. 2008 Dec;81(3):497-503. doi: 10.1007/s00253-008-1675-z. Epub 2008 Sep 16.
We describe the isolation and characterization of a gene (MAELO) that encodes a fatty acid elongase from arachidonic acid-producing fungus Mortierella alpina 1S-4. Although the homologous MAELO gene had already been isolated from M. alpina ATCC 32221, its function had not yet been identified. The MAELO gene from M. alpina 1S-4 was confirmed to encode a fatty acid elongase by its expression in yeast Saccharomyces cerevisiae. Analysis of the fatty acid composition of the yeast transformant revealed the accumulation of 22-, 24-, and 26-carbon saturated fatty acids. On the other hand, RNA interference of the MAELO gene in M. alpina 1S-4 was carried out. The gene-silenced strain obtained on RNA interference exhibited low contents of 20-, 22-, and 24-carbon saturated fatty acids and a high content of stearic acid (18 carbons), compared with those in the wild strain. The enzyme encoded by the MAELO gene was demonstrated to be involved in the biosynthesis of 20-, 22-, and 24-carbon saturated fatty acids in M. alpina 1S-4.
我们描述了从产花生四烯酸的高山被孢霉1S-4中分离和鉴定一个编码脂肪酸延长酶的基因（MAELO）的过程。尽管同源的MAELO基因已从高山被孢霉ATCC 32221中分离出来，但其功能尚未确定。通过在酿酒酵母中表达，证实了高山被孢霉1S-4的MAELO基因编码一种脂肪酸延长酶。对酵母转化体脂肪酸组成的分析揭示了22碳、24碳和26碳饱和脂肪酸的积累。另一方面，对高山被孢霉1S-4中的MAELO基因进行了RNA干扰。与野生菌株相比，通过RNA干扰获得的基因沉默菌株中20碳、22碳和24碳饱和脂肪酸含量较低，而硬脂酸（18碳）含量较高。结果表明，MAELO基因编码的酶参与了高山被孢霉1S-4中20碳、22碳和24碳饱和脂肪酸的生物合成。
