Jiang F, Rizavi H S, Greenberg M L
Department of Biological Sciences, Wayne State University, Detroit, MI 48202, USA.
Mol Microbiol. 1997 Nov;26(3):481-91. doi: 10.1046/j.1365-2958.1997.5841950.x.
Cardiolipin is a unique dimeric phospholipid, which is present throughout the eukaryotic kingdom and is specifically localized in mitochondrial membranes. It is widely believed that mitochondria possess an essential requirement for this phospholipid. To determine whether cardiolipin is essential for yeast growth, we generated a cardiolipin synthase null mutant by disrupting the CLS1 gene (open reading frame YDL142c on chromosome IV) of Saccharomyces cerevisiae. Biochemical analysis of the mutant indicated that it had no cardiolipin synthase activity and no cardiolipin in its membranes. The enzyme phosphatidylglycerolphosphate synthase, which catalyses the committed step of the cardiolipin pathway, remained unaffected in the null mutant. Haploid cells containing the null allele are viable in media containing glucose, galactose or glycerol/ethanol as the sole carbon source, although growth in galactose or glycerol/ethanol is somewhat reduced in the mutant compared with the wild type. These results indicate that cardiolipin is not essential for the growth of S. cerevisiae in fermentable or non-fermentable carbon sources.
心磷脂是一种独特的二聚体磷脂，存在于整个真核生物界，且特异性地定位于线粒体膜中。人们普遍认为线粒体对这种磷脂有基本需求。为了确定心磷脂对酵母生长是否必不可少，我们通过破坏酿酒酵母的CLS1基因（位于第四条染色体上的开放阅读框YDL142c）构建了一个心磷脂合酶缺失突变体。对该突变体的生化分析表明，它没有心磷脂合酶活性，其膜中也没有心磷脂。催化心磷脂合成途径关键步骤的磷脂酰甘油磷酸合酶在该缺失突变体中未受影响。含有缺失等位基因的单倍体细胞在以葡萄糖、半乳糖或甘油/乙醇作为唯一碳源的培养基中能够存活，不过与野生型相比，该突变体在半乳糖或甘油/乙醇中的生长有所减缓。这些结果表明，心磷脂对于酿酒酵母在可发酵或不可发酵碳源中的生长并非必不可少。
