Henry S M, Hodge L D
J Cell Biol. 1983 Jul;97(1):166-72. doi: 10.1083/jcb.97.1.166.
Evidence is presented that the structural rearrangements in late mitosis are accompanied by an alteration in membrane lipid synthesis. This evidence was derived from analyzing phospholipid classes after rapid-labeling, as well as from determining the intracellular site of incorporation of choline by HeLa S3 cells as they progressed from metaphase into early interphase (G1). Compared with postmitotic cell data, the recent mitotic cell data indicate a specific two- to threefold increase in the net synthesis of phosphatidylcholine (PC) species, which appeared to contain the more saturated fatty acids. Since this was observed with glycerol, choline, and orthophosphate labelings, and not with methyl labeling, it appears that the CDP-choline plus diacylglycerol pathway rather than the phosphatidylethanolamine to PC pathway was augmented. Electron microscope autoradiography of anaphase, telophase, and early G1 cells demonstrated that the reformed nuclear envelope was the incorporation site of a significant proportion of the newly synthesized PC. This incorporation occurred by early telophase prior to chromosome decondensation. The potential significance of PC metabolism with regard to membrane rearrangements, such as nuclear envelope reformation, is discussed.
有证据表明,有丝分裂后期的结构重排伴随着膜脂合成的改变。该证据来自于快速标记后对磷脂类别的分析,以及在HeLa S3细胞从中期进入早期间期(G1期)过程中对胆碱掺入细胞内位点的测定。与有丝分裂后细胞的数据相比,近期有丝分裂细胞的数据表明,磷脂酰胆碱(PC)种类的净合成有特定的两到三倍的增加,这些PC似乎含有更多的饱和脂肪酸。由于在甘油、胆碱和正磷酸盐标记中观察到了这种情况,而在甲基标记中未观察到,因此似乎是CDP-胆碱加二酰基甘油途径而非磷脂酰乙醇胺转化为PC的途径得到了增强。对后期、末期和早期G1期细胞的电子显微镜放射自显影显示,重新形成的核膜是大量新合成PC的掺入位点。这种掺入在末期早期染色体解聚之前就已发生。文中讨论了PC代谢对于膜重排(如核膜重新形成)的潜在意义。