Studies on regulation of cell growth of budding yeast by platelet-activating factor (PAF)

血小板活化因子（PAF）调控芽殖酵母细胞生长的研究

基本信息

批准号：
09660104
负责人：
NAKAYAMA Reiko
金额：
$ 2.18万
依托单位：
Kyoto Women's University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

项目摘要

The purpose of this investigation was to define the possible function of PAF (platelet-ctivating factor) in budding yeast in relation to cell growth regulation.1.Changes in PAF Production and Distribution of S.cerevisiae cells in Various phase of Life CycleWe examined the changes of PAF production and its cellular distribution in S.cerevisiae during cell cycle. PAF production of cells was the highest at G_1 phase, and 90 % of PAF was localized in the cell surface. And, we found that the yeast produces PAF in early stage of mating process in response to the mating hormone. Furthermore, STE6 gene disruptant (MAT a cell) was made by using ste6 : URA3, and PAF production and distribution of the disruptant were compared with those of wild type cells. Results indicated that Ste6p encoded by STE6 gene, transport not only lipopeptide mating hormone a-factor, but also lipid mediator PAF.2.Mechanism of Regulation of Cell Growth by PAFPAF was added to culture medium and yeast cell growth was monitored. PAF inhibited cell growth dose-ependent manner. We obtained PAP-insensitive mutants, and examined the effects of PAF on the concentration of intracellular cAMP, activities of membrane adenylate cyclase and metabolism of phosphatidyl inositol (cellular IP_3). Results showed that mechanisms of PAF-induced inhibition of cell growth were related to RAS-cAMP pathway and/or the signal transduction mediated by IP_3.3.Cloning of PAF-ensitive GenePAF-sensitive gene, GPR1 was isolated. Gprlp, encoded by GPR1 gene was not PAF receptor, but it is aG-protein coupled receptor which localized at plasma membrane, and regulates the cellular cAMP level in response to the extracellular signal such as glucose.

这项研究的目的是定义PAF（血小板静态因子）与细胞生长调节相关的萌芽酵母中的可能功能。1。PAF产生和塞维维西亚链球菌细胞在各个阶段的生命阶段的分布中，在细胞周期中，PAF的各个阶段在生命周期中的各个阶段的变化及其在细胞周期中的细胞分布的变化。细胞的PAF产生在G_1期最高，而90％的PAF位于细胞表面。而且，我们发现酵母在响应交配激素的早期阶段产生PAF。此外，使用ste6：ura3进行Ste6基因破坏剂（MAT A细胞），并将破坏因子的PAF产生和分布与野生型细胞的分布进行比较。结果表明，由Ste6基因编码的Ste6P不仅转运脂肽交配激素A因子，而且还将PAFPAF调节细胞生长调节细胞生长的机制被添加到培养基和酵母菌细胞生长中。 PAF抑制细胞生长剂量依赖性方式。我们获得了PAP不敏感的突变体，并检查了PAF对细胞内cAMP浓度的影响，腺苷酸环化酶的活性以及磷脂酰肌醇的代谢（细胞IP_3）。结果表明，PAF诱导的细胞生长抑制的机制与IP_3.3.CAF敏感性基因存敏感基因介导的RAS-cAMP途径和/或信号转导有关，分离了GPR1。由GPR1基因编码的GPRLP不是PAF受体，而是Ag蛋白偶联受体，该受体位于质膜上，并根据细胞外信号（例如葡萄糖）调节细胞cAMP水平。