Enzymes and genes involved in phosphatidylcholine signaling

三种磷脂酶D同位素的cDNAs，rPLD 1a，其splice variant rPLD 1b，以及一种新的同位素rPLD 2已从大鼠tissues克隆。rPLD1a and b？ed Arf， Rho， and PIP？D22？D2， but rPLD2 only PIP 2。内皮原磷脂酶抑制剂在低浓度下有效（10-5 M）在猪结肠mucosa中被发现，并被纯化和识别为lysoPS、PI和lysoPI。磷脂酶D活动的水平显著增加了人类乳腺癌和大鼠实验中诱导的结肠癌细胞的诊断，并与不良历史上正常的诊断相比较。因此，磷脂酶D可以用作肿瘤标记物，也可以用作抗肿瘤药物治疗的目标。磷脂酶D cDNA是从黑色素瘤的胚胎中获得的。预测的氨基酸序列包括1278个氨基酸溶液，含有145 kd的分子质量，具有PX和PH域和两个由HKD动机组成的两个。The Enzyme expressed in COS cells强烈依赖于PIP，D22，D2， a ... More 第一次被Arf的添加物折叠了两次。基因合成的10倍被映射到染色体II的右臂（42 A16 -18）。在原位杂交被揭示，mRNA在蛋内表达，早期的blastoderm，但在较晚的blastoderm阶段消失了一些时间，然后在想象阶段重新出现，建议磷酸酶D的作用在早期的胚胎发育的控制中。磷脂酶van被归类为低和高分子重量的同位素。一种新型的低分子重量酶被克隆和命名为脂磷酸酶II，也含有GXSXG动机，属于酯化酶家族作为脂磷酸酶I。在与Michel的合作中，我们展示了脂磷脂酶我可以调节NO合成酶的依赖，并在NO合成的规则中提出了酶的作用。在高分子重量脂磷脂酶中，cDNA已从大鼠肝脏中克隆。酶有意义地重新组装的天冬氨酸酶和含有leucine zipper和ankyrin重复。这一序列与低分子重量的脂磷酸酶是不一样的。由高分子重量酶体介导的transacylation被试过。它将脂肪酸附着在不同分子分子中的不同位置上的磷酸盐-1和-2位置上的磷酸盐。在特定的情况下，花生酸从sn-2的位置转移到sn-1的位置，以一种可确定的速率转移到1-花生酸盐胆碱，这是一种众所周知的无烷酰胺前体。Less（低）

cDNAs for three phospholipase D isozymes, rPLD1a, its splice variant rPLD1b, and a new isozyme rPLD2 were cloned from rat tissues. rPLD1a and b required Arf, Rho, and PIPィイD22ィエD2, but rPLD2 only PIP2. Endogenous phospholipase inhibitors effective at low concentrations (10-5 M) were discovered in pig colon mucosa, and were purified and identified as lysoPS, PI, and lysoPI. The levels of phospholipase D activity were increased significantly in tissues from human breast cancer and rat experimentally induced colon cancer as compared with the adjacent histologically normal tissues. Thus, phospholipase D could be used as a tumor marker and also as the target of anti-tumor drug therapy.Phospholipase D cDNA was obtained from the embryo of Drosophila melanogaster. The predicted amino acid sequence comprised 1278 amino acid residues with a molecular mass of 145 kd with the PX and PH domains and two conserved HKD motifs. The enzyme expressed in COS cells was strongly dependent on PIPィイD22ィエD2, a … More nd was stimulated about two-fold by the addition of Arf. The gene comprising 10 exons was mapped to the right arm of chromosome II (42A16-18). In situ hybridization revealed that mRNA was expressed in egg, early blastoderm, but disappeared for some period of time in the late stage of blastoderm, and then reappeared in the imaginal stage, suggesting a role of phospholipase D in the control of early embryogenesis of Drosophila melanogaster.Lysophospholipase van be classified into low and high molecular-weight isoforms. A novel low molecular weight enzyme was cloned and named lysophospholipase II, which also contained the GXSXG motif and belonged to the esterase family as Lysophospholipase I. In collaboration with Michel, we showed that lysophospholipase I mediates the depalmitoylation of NO synthase, suggesting a role of the enzyme in the regulation of NO synthesis. cDNA for the high molecular-weight lysophospholipase was cloned from rat liver. The enzyme significantly resembled asparaginase and contained leucine zipper and ankyrin repeat. The sequence was dissimilar to that of the low molecular-weight lysophospholipase. The transacylation mediated by the high molecular-weight enzyme was examined. It transferred the fatty acid attached to the sn-1 and -2 positions of lysophospholipids to a vacant position in the different molecule of lysophospholipid. In particular, arachidonic acid was transferred from the sn-2 position to the sn-1 position at a considerable rate to yield 1-arachidonoyl phosphatidylcholine that is a well-known precursor of anandamide. Less