The roles of lipids expand beyond the basic building blocks of biological membranes. In addition to forming complex and dynamic barriers, the thousands of different lipid species in the cell contribute to essentially all the processes of life. Specific lipids are increasingly identified in cellular processes, including signal transduction, membrane trafficking, metabolic control and protein regulation. Tight control of their synthesis and degradation is essential for homeostasis. Most of the lipid molecules in the cell originate from a small number of critical intermediates. Thus, regulating the synthesis of intermediates is essential for lipid homeostasis and optimal biological functions. Cytidine diphosphate diacylglycerol (CDP-DAG) is an intermediate which occupies a branch point in lipid metabolism. CDP-DAG is incorporated into different synthetic pathways to form distinct phospholipid end-products depending on its location of synthesis. Identification and characterization of CDP-DAG synthases which catalyze the synthesis of CDP-DAG has been hampered by difficulties extracting these membrane-bound enzymes for purification. Recent developments have clarified the cellular localization of the CDP-DAG synthases and identified a new unrelated CDP-DAG synthase enzyme. These findings have contributed to a deeper understanding of the extensive synthetic and signaling networks stemming from this key lipid intermediate.

中文翻译：

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CDP-二酰基甘油，脂质代谢的关键中间体。

脂质的作用超出了生物膜的基本组成部分。除了形成复杂和动态的屏障外，细胞中成千上万种不同的脂质种类基本上参与了生命的所有过程。在细胞过程，包括信号转导，膜运输，代谢控制和蛋白质调节中，越来越多地识别出特定的脂质。严格控制其合成和降解对于体内平衡至关重要。细胞中的大多数脂质分子都来自少量的关键中间体。因此，调节中间体的合成对于脂质稳态和最佳生物学功能至关重要。胞苷二磷酸二酰基甘油（CDP-DAG）是在脂质代谢中占据分支点的中间体。CDP-DAG取决于其合成位置，被掺入到不同的合成途径中以形成独特的磷脂终产物。由于难以提取这些膜结合酶进行纯化，阻碍了催化CDP-DAG合成的CDP-DAG合成酶的鉴定和表征。最近的发展澄清了CDP-DAG合酶的细胞定位，并确定了一种新的不相关的CDP-DAG合酶。这些发现有助于更深入地了解源自这种关键脂质中间体的广泛的合成和信号网络。由于难以提取这些膜结合酶进行纯化，阻碍了催化CDP-DAG合成的CDP-DAG合成酶的鉴定和表征。最近的发展澄清了CDP-DAG合酶的细胞定位，并确定了一种新的不相关的CDP-DAG合酶。这些发现有助于更深入地了解源自这种关键脂质中间体的广泛的合成和信号网络。由于难以提取这些膜结合酶进行纯化，阻碍了催化CDP-DAG合成的CDP-DAG合成酶的鉴定和表征。最近的发展澄清了CDP-DAG合酶的细胞定位，并确定了一种新的不相关的CDP-DAG合酶。这些发现有助于更深入地了解源自这种关键脂质中间体的广泛的合成和信号网络。