Contribution of different pathways to the supply of phosphatidylethanolamine and phosphatidylcholine to mitochondrial membranes of the yeast Saccharomyces cerevisiae
Contribution of different pathways to the supply of phosphatidylethanolamine and phosphatidylcholine to mitochondrial membranes of the yeast Saccharomyces cerevisiae
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DOI：
10.1016/j.bbalip.2004.09.007
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发表时间：
2004-11-08
影响因子：
4.8
通讯作者：
Daum, G
中科院分区：
文献类型：
--
作者：
Bürgermeister, M;Birner-Grünberger, R;Daum, G
在酵母中，三种生物合成途径导致磷脂酰乙醇胺 (PtdEtn) 的形成： (i) 线粒体中磷脂酰丝氨酸脱羧酶 1 (Psd1p) 对磷脂酰丝氨酸 (PtdSer) 进行脱羧； (ii) PtdSer 在高尔基体/液泡室中被 Psd2p 脱羧； (iii) 肯尼迪途径的 CDP-乙醇胺 (CDP-Etn) 分支。酵母的主要磷脂磷脂酰胆碱 (PtdCho) 是通过 PtdEtn 的甲基化或通过肯尼迪途径的 CDP-胆碱分支形成的。为了研究这些途径对向线粒体膜供应 PtdEtn 和 PtdCho 的贡献，分别用 [H-3] 丝氨酸和 [C-14] 乙醇胺，或用 [H-3] 丝氨酸和 [C-14] 胆碱进行体内标记实验，并用 psd1Delta 和 psd2Delta 突变体进行随后的细胞分级分离。通过比较不同菌株的标记模式可知，细胞和线粒体PtdEtn的主要来源是Psd1p。然而，由 Psd2p 或 CDP-Etn 途径形成的 PtdEm 可以导入线粒体，但效率中等。与线粒体相反，微粒体 PtdEtn 主要来源于 CDP-Etn 途径。 Psd2p 形成的 PtdEm 是 PtdCho 合成的首选底物。源自不同途径的 PtdCho 似乎从单个 PtdCho 池供应至亚细胞膜。因此，PtdEtn生物合成的不同途径在PtdEtn组装到细胞膜中发挥不同的作用。 (C) 2004 Elsevier B.V. 保留所有权利。
In the yeast, three biosynthetic pathways lead to the formation of phosphatidylethanolamine (PtdEtn): (i) decarboxylation of phosphatidylserine (PtdSer) by phosphatidylserine decarboxylase 1 (Psd1p) in mitochondria; (ii) decarboxylation of PtdSer by Psd2p in a Golgi/vacuolar compartment; and (iii) the CDP-ethanolamine (CDP-Etn) branch of the Kennedy pathway. The major phospholipid of the yeast, phosphatidylcholine (PtdCho), is formed either by methylation of PtdEtn or via the CDP-choline branch of the Kennedy pathway. To study the contribution of these pathways to the supply of PtdEtn and PtdCho to mitochondrial membranes, labeling experiments in vivo with [H-3]serine and [C-14]ethanolamine, or with [H-3]serine and [C-14] choline, respectively, and subsequent cell fractionation were performed with psd1Delta and psd2Delta mutants. As shown by comparison of the labeling patterns of the different strains, the major source of cellular and mitochondrial PtdEtn is Psd1p. PtdEm formed by Psd2p or the CDP-Etn pathway, however, can be imported into mitochondria, although with moderate efficiency. In contrast to mitochondria, microsomal PtdEtn is mainly derived from the CDP-Etn pathway. PtdEm formed by Psd2p is the preferred substrate for PtdCho synthesis. PtdCho derived from the different pathways appears to be supplied to subcellular membranes from a single PtdCho pool. Thus, the different pathways of PtdEtn biosynthesis play different roles in the assembly of PtdEtn into cellular membranes. (C) 2004 Elsevier B.V. All rights reserved.