Study on Membrane Function by the Mutants With Requirement for Phosphatidylinositol.

磷脂酰肌醇需要突变体的膜功能研究。

• 批准号: 63560074
• 负责人: MATSUZAKI Hiroshi
• 金额: $ 1.22万
• 依托单位: Saitama University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63560074/
• 关键词: Biomembrane; Phospholipid; Phosphatidylinositol; Cultured Mammalian Cells; Mutant; Myo-Inositol; ミオ・イノシト-ル; ホスファチジルイノシトール; ミオ-イノシトール; 細胞増殖; 培養癌細胞; Biomembrane; Phospholipid; Phosphatidylinositol; Cultured Mammalian Cells; Mutant; Myo-Inositol; ミオ・イノシト-ル; ホスファチジルイノシトール; ミオ-イノシトール; 細胞増殖; 培養癌細胞

Phosphatidylinositol (PI) is one of the major membrane lipids in eukaryotic cells. Its phosphorylated or degraded derivatives are now well known to be involved in important signal transduction pathways.The physiological function of phosphatidylinositol involving synthesis and assembly of bio-membrane was examined with mouse FM3A cells, derived from spontaneous mammary carcinoma of C3H/He mouse FM3A cells.Above 10 uM of myo-inositol (Ins) was required for growth of this cell line. The metabolic label experiments and quatitative analysis of cellular phospholipids in mouse FM3A cells grown in the presence of PI showed 1) increase of PI content, 2) stimulation of phosphoinositides synthesis, 3) decrease of phosphatidylglycerol (PG) content, and 4) stimulation of [^3H]Ins incorporation into lipid fractions. [^3H]labeled PI was incorporated into cellular lipid fractions without influence with the concentration of Ins or the kinds of fetal calf serum during pre-culture. Incorporation of [^3H] … More Ins into lipid fraction by these homogenates (PI synthesizing activity) was assayed at about neutral pH (pH 7.4) and the low concentration of Ins (11 uM). CDP-diacylglycerol independent incorporation of [^3H]Ins into lipid fraction (PIE) was 1.5 fold greater than CDP-diacylglycerol dependent one (PIS). With addition of PI, PIS was almost inhibited, and PIE was increased in proportion to the concentration of supplemented PI. In one of the mutants with requirement for PI on the agar plate (6-2-III), incorporation of [^3H]Ins into cells or cellular lipid fraction reduced to 40 %, 60-70% respectively. The mutant revealed the longer generation time (1.5 - 2 fold) and decrease of cell aggregation than the wild type's. In another mutant (17-6-I), even in the medium without Ins, the addition of PI could maintained the higher growth rate and incorporation of [^3H]PI into cellular lipid fraction was increased about 1.4 fold. The results that (1) the manipulation of cellular PI by the medium supplemented with PI, contribution of PI : Ins exchange enzyme activity to the increase of content of cellular PI and alteration of Ins or PI incorporation into cells or lipid fraction in PI auxotrophic mutants suggested the important consequences to clarify the physiological function of PI and Ins in eukaryotic biomembrane. Less

磷脂酰肌醇（PI）是真核细胞中主要的膜脂质之一。 Its phosphorylated or degraded derivatives are now well known to be involved in important signal transduction pathways.The physical function of phosphatidylinositol involving synthesis and assembly of bio-membrane was examined with mouse FM3A cells, derived from spontaneous mammary carcinoma of C3H/He mouse FM3A cells.Above 10 uM of myo-inositol (Ins) The metabolic label在存在PI的情况下生长的小鼠FM3A细胞中细胞磷脂的实验和非质量分析显示1）PI含量的增加，2）刺激磷酸肌醇合成，3）磷脂酰甘油（PG）含量（PG）含量和4）刺激[^3H] Insofties ins of [^3H] Insoftions ins of [^3H]。 [^3H]将标记的PI纳入了细胞脂质级分中，而没有影响INS的浓度或胎儿小牛血清的浓度。在这些匀浆（PI合成活性）中，将[^3H]的掺入[^3H]……在中性pH（pH 7.4）和低浓度INS（11 um）中分配了更多的INS（PI合成活性）。 [^3H] INS中脂质分数（PIE）的CDP-二酰基甘油独立掺杂缔合比CDP-diacyl-甘油依赖于CDP-diacyl-甘油大1.5倍（PIS）。加上PI，几乎抑制了PI，并且与补充Pi的浓度成比例增加了PIE。在其中一个突变体中，在琼脂板上需要PI（6-2-III），将[^3H] INS掺入细胞或细胞脂质分数分别降低至40％，60-70％。该突变体揭示了比野生型更长的生成时间（1.5-2倍）和细胞聚集的减少。在另一个突变体（17-6-i）中，即使在没有INS的培养基中，PI的添加也可以维持[^3H] PI在细胞脂质分数中的较高生长速率，并将其掺入较高的比率约为1.4倍。 The results that (1) the manipulation of cellular PI by the medium supplemented with PI, contribution of PI: Ins exchange enzyme activity to the increase of content of cellular PI and alteration of Ins or PI incorporated fraction into cells or lipid fraction in PI auxotrophic mutants suggested the important consequences to clarify the Physiological function of PI and Ins in eukaryotic biomembrane.较少的