Regulation of Cell Phospholipid Metabolism by Phospholipase A2

磷脂酰胆碱（PC）是哺乳动物细胞周围膜中含量最多的脂肪。这种脂肪对细胞存活是绝对必要的，因为不能制造PC的细胞会迅速被诱导经历程序性细胞死亡。因此，对于细胞来说，保持细胞膜中PC的相对恒定水平是很重要的。这是通过“体内平衡”实现的，即PC合成和降解之间的平衡。许多证据表明，PC的合成是由一种特殊的酶，CT控制的。该研究小组已经证明，PC的降解也可能由一种特定的酶iPLA2控制。因此，将进行实验来确定细胞膜中PC量的变化是否会引起哺乳动物细胞中iPLA2量的代偿性变化。如果是这种情况，那么将检查归纳的机制。总之，这些研究应该为细胞生物学的一个基本方面提供见解，即细胞用来维持其膜的机制。

Phosphatidylcholine (PC) is the most abundant fat in the membranes that surround mammalian cells. This fat is absolutely essential for cell survival, as cells that cannot make PC are rapidly induced to undergo programmed cell death. Therefore, it is important for cells to maintain relatively constant levels of PC in their membranes. This is achieved through "homeostasis", a balance between the synthesis and degradation of PC. Many lines of evidence indicate that the synthesis of PC is controlled by a specific enzyme, CT. This research group has demonstrated that the degradation of PC may also be controlled by a specific enzyme, iPLA2. Therefore, experiments will be performed to determine if changes in the amount of PC in cell membranes induce compensatory changes in the amount of iPLA2 in mammalian cells. If this is the case, then the mechanism of the induction will be examined. Together, these studies should provide insight into a basic aspect of cell biology, the mechanisms that cells use to maintain their membranes.