ANOMALOUSLY SLOW MOBILITY OF FLUORESCENT LIPID PROBES IN THE PLASMA-MEMBRANE OF THE YEAST SACCHAROMYCES-CEREVISIAE
ANOMALOUSLY SLOW MOBILITY OF FLUORESCENT LIPID PROBES IN THE PLASMA-MEMBRANE OF THE YEAST SACCHAROMYCES-CEREVISIAE
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DOI：
10.1007/bf02791320
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发表时间：
1993-01-01
影响因子：
2.4
通讯作者：
AXELROD, D
中科院分区：
文献类型：
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作者：
GREENBERG, ML;AXELROD, D
我们测量了两种荧光脂质探针双十八烷基吲哚羰花青（dil）和四甲基罗丹明磷脂酰乙醇胺（R-PE）在酿酒酵母inol和opi 3原生质球质膜上的横向迁移率。这些是特征良好的菌株，在肌醇和磷脂酰胆碱生物合成途径中发生突变。膜磷脂组成的改变，通过生长这些突变体在存在或不存在肌醇和胆碱。通过光漂白后的荧光恢复（FRAP）测量横向迁移率。采用CCD数字成像的显微荧光偏振产生了脂质探针dil的有序取向分布，证实了至少一种探针在很大程度上被掺入到双层膜中。我们的研究结果表明，无论脂质成分是否接近正常或磷脂酰肌醇和磷脂酰胆碱的相对组成发生显着变化，两种突变体的脂质探针的流动性都非常缓慢。胰蛋白酶化的原生质球，以消除表面蛋白导致显着增加的横向流动性。然而，即使在胰蛋白酶化的原生质球中，迁移率仍然略低于在哺乳动物细胞膜中观察到的迁移率，例如在此测试的大鼠平滑肌培养细胞用于比较。
We measured the lateral mobility of two fluorescent lipid probes dioctadecylindocarbocyanine (dil) and tetramethyl rhodamine phosphatidylethanolamine (R-PE) in the plasma membranes of Saccharomyces cerevisiae inol and opi3 spheroplasts. These are well-characterized strains with mutations in the inositol and phosphatidylcholine biosynthetic pathways. Membrane phospholipid composition was altered by growing these mutants in the presence or absence of inositol and choline. Lateral mobility was measured by fluorescence recovery after photobleaching (FRAP). Microscopic fluorescence polarization employing CCD digital imaging produced an ordered orientation distribution of the lipid probe dil, confirming that at least one of the probes was largely incorporated into the bilayer membrane. Our results demonstrated anomalously slow mobility of both lipid probes for both mutants, regardless of whether the lipid composition was near normal or dramatically altered in relative composition of phosphatidylinositol and phosphatidylcholine. Trypsinization of the spheroplasts to remove surface proteins resulted in markedly increased lateral mobility. However, even in trypsinized spheroplasts, mobility was still somewhat lower than the mobility observed in the membrane of mammalian cells, such as rat smooth muscle culture cells tested here for comparison.