Molecular genetic study on the metabolism and function of phosphatidylserine in mammalian cells

为了揭示磷脂酰丝氨酸(PS)生物合成的机制和PS的功能，我们先前分离了一个PS生物合成缺陷的哺乳动物细胞突变体。利用该突变体，我们发现PS合酶和PS脱羧酶在哺乳动物细胞PS的形成中起着重要的作用。在本研究中，为了进一步研究PS合成的分子机制，我们试图纯化PS合成酶，并分离PS脱羧酶缺陷突变株。(1)利用PS合成酶C-端部分的寡肽制备PS合成酶的多克隆抗体。(2)用多种洗涤剂对PS合成酶进行增溶。然而，我们没有找到良好的条件来溶解该酶。(3)利用基因打靶技术，在CHO细胞中缺失PS脱羧酶基因。通过这种方式，我们获得了一个突变的Ps脱羧酶基因缺陷。我们的结果还为时过早，所以我们将在未来几年继续上述研究。

To reveal the mechanism of phosphatidylserine (PS) biosynthesis and function of PS, we previously isolated a mammalian cell mutant defective in PS biosyntheses. By using this mutant, we found that PS synthase and PS decarboxylase played important roles in PS formation in mammalian cells. In the present study, to further characterize the molecular mechanism of PS synthesis, we tried to purify PS synthase and to isolate mutants defective in PS decarboxylase.(1) We made polyclonal antibody to PS synthase by using a oligopeptide which corresponded to the C-terminal part of PS synthase.(2) We tried to solubilize PS synthase by using various kinds of detergents. However, we could not find good conditions to solubilize the enzyme. (3) We desrupted the gene of PS decarboxylase in CHO cells by gene targeting. In this way, we obtained a mutant defective in one of the Ps decarboxylase genes.Our results are still premature and so we will continue the above studies for coming several years.