The structure and function of molecules which regulate the cell membrane phospholipid bi-layer.

调节细胞膜磷脂双层的分子的结构和功能。

• 批准号: 13680687
• 负责人: TAKEYA Hiroyuki
• 金额: $ 2.11万
• 依托单位: University of Occupational and Environmental Health (2002)Mie University (2001)
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13680687/
• 关键词: cell membrane; phospholipid; platelet; phosphatidylserine; apoptosis; cancer; EFハンド; カルシウム; 分子生物学

Plasma membrane has an asymmetric lipid distribution. Whereas both plasma membrane leaflets are mainly composed of choline-containing phospholipids (phosphatidylcholine and sphingomyelin), the inner leaflet is enriched relative to the outer leaflet in primary amine-containing phospholipids (phosphatidylserine (PS), and phosphatidylethanolamine). Disruption of this normal lipid distribution is an important element in blood platelet activation and in apoptosis. Loss of lipid asymmetry with concomitant PS exposure at the surface of activated platelets promotes assembly of active enzyme-substrate complexes of the blood coagulation cascade. The PS exposure on apoptotic cells triggers recognition and clearance by phagocytes. Phospholipid scramblase 1 (PLSCR1) has been proposed to catalyze both inward and outward transbilayer lipid movement in response to elevated cytoplasmic Ca^<2+>, and it may contribute to cell surface PS exposure during platelet activation and early stages of apoptosis. We have identified 5 alternatively spliced scrambrase transcripts by PCR of human fetal kidney cDNA library, using oligonucleotide primers to regions containing the start and stop codons of phospholipid scramblase 1 (PLSCR1). In all variants of PLSCR1 mRNA (PLSCR1 mRNA was designated Scrla), the exon 4 of Scrla is spliced out, resulting in a frame shift in the exon 5 coding sequence, generating a premature stop codon in the exon 5. While the full-length Scrla encodes for a protein of 318 amino acids (PLSCR1α), all variants encode a protein of 41 amino acids (PLSCR1β). A novel carboxyl-terminal (C-terminal) tail of 10 amino acids does not show any homology to sequences in the protein database. PLSCR1β contains Pro-X-X-Pro and Pro-Pro-X-Tyr motifs, which may serve as potential binding sites for proteins containing SH3 and WW domains, respectively. PLSCR1β may interact with an adapter or signaling molecule via these motifs, thus possiblly regulating PLSCR1α function.

质膜具有不对称的脂质分布。虽然这两个质膜小叶主要由含胆碱的磷脂（磷脂酰胆碱和鞘磷脂）组成，但内小叶相对于外小叶富含含初级胺的磷脂（磷脂酰丝氨酸（PS）和磷脂酰乙醇胺）。这种正常脂质分布的破坏是血小板活化和细胞凋亡的重要因素。脂质不对称的丧失伴随着活化血小板表面的PS暴露，促进了凝血级联中活性酶-底物复合物的组装。PS暴露在凋亡细胞上触发吞噬细胞的识别和清除。磷脂重组酶1 （PLSCR1）被认为在细胞质Ca^<2+>升高的情况下催化向内和向外的跨双分子层脂质运动，并可能在血小板激活和细胞凋亡的早期阶段参与细胞表面PS暴露。我们利用含有磷脂转录酶1 （PLSCR1）起始密码子和终止密码子区域的寡核苷酸引物，对人胎肾cDNA文库进行PCR鉴定，鉴定出5个选择性剪接的转录本。在PLSCR1 mRNA的所有变体中（PLSCR1 mRNA被命名为scla）， scla的外显子4被剪接掉，导致外显子5编码序列的帧移位，在外显子5中产生一个过早的停止密码子。全长scra编码318个氨基酸的蛋白（PLSCR1α），而所有变体编码41个氨基酸的蛋白（PLSCR1β）。一个新的羧基末端（c端）尾部的10个氨基酸不显示任何同源性的序列在蛋白质数据库。PLSCR1β含有Pro-X-X-Pro和Pro-Pro-X-Tyr基序，它们可能分别作为含有SH3和WW结构域的蛋白质的潜在结合位点。PLSCR1β可能通过这些基序与适配器或信号分子相互作用，从而可能调节PLSCR1α的功能。

项目成果

Takeya H.: "Synergistic effect of sphingosine 1-phosphate on thrombin-induced tissue factor expression in endothelial cells"Blood. (in press). (2003)

Takeya H.：“1-磷酸鞘氨醇对内皮细胞中凝血酶诱导的组织因子表达的协同作用”血液。

武谷浩之: "プロテアーゼの分類"医学のあゆみ. 198・1. 3-9 (2001)

竹谷宏之：“蛋白酶的分类”医学史198・1。

Takeya, H.: "Synergistic effect of sphingosine 1-phosphate on thrombin-induced tissue factor expression in endothelial cells"Blood. (in press). (2003)

Takeya，H.：“1-磷酸鞘氨醇对内皮细胞中凝血酶诱导的组织因子表达的协同作用”血液。

Hiroyuki Takeya, Esteban C. Gabazza, Shinya Aoki, Hikaru Ueno and Koji Suzuki: "Synergistic effect of sphingosine 1-phosphate on thrombin-induced tissue factor expression in endothelial cells"Blood. (in press). (2003)

Hiroyuki Takeya、Esteban C. Gabazza、Shinya Aoki、Hikaru Ueno 和 Koji Suzuki：“1-磷酸鞘氨醇对内皮细胞中凝血酶诱导的组织因子表达的协同作用”血液。

Gabazza, E.C.: "Adenosine inhibits thrombin-induced expression of tissue factor on endothelial cells by a nitric oxide-mediated mechanism"Clln.Sci(Lond). 102・2. 165-175 (2002)

Gabazza，E.C.：“腺苷通过一氧化氮介导的机制抑制凝血酶诱导的内皮细胞表达”Clln.Sci（伦敦）165-175。