Differentiation-related differences in the plasma membrane phospholipid asymmetry of myogenic and fibrogenic cells.
Differentiation-related differences in the plasma membrane phospholipid asymmetry of myogenic and fibrogenic cells.
复制标题
肌原细胞和纤维原细胞质膜磷脂不对称性的分化相关差异。
DOI：
10.1016/0005-2736(83)90442-x
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
Horwitz,AF
中科院分区：
文献类型：
--
作者：
Sessions,A;Horwitz,AF
我们测定了磷脂酰乙醇胺和磷脂酰丝氨酸两种氨基磷脂在鸡胚胎成纤维细胞和成肌细胞质膜上的不对称分布。在非穿透条件下，用两种不同的胺化试剂--三硝基苯磺酸盐和异硫代乙酰亚硫酸酯孵育直立式膜制剂。膜由内向外与三硝基苯磺酸孵育。在成纤维细胞中，相似的平台值表明35%的磷脂酰乙醇胺和20%的磷脂酰丝氨酸是外部处理的。这些值与之前在成纤维细胞质膜上的测量结果一致。然而，在成肌细胞中，获得了标记平台，这表明65%的磷脂酰乙醇胺和45%的磷脂酰丝氨酸是外部处置的。这意味着质膜外部小叶上潜在的融合性脂质增加了2-3倍。这种氨基磷脂在成肌细胞中的独特分布贯穿于成肌细胞的发育阶段，在此阶段，成肌细胞能够在培养中融合并形成肌管。从这些结果中可以得出两个推论。首先，成肌细胞中氨基磷脂的外源浓度显著高于成纤维细胞或红细胞。这种定向可能有助于其融合能力。第二，尽管大量的外部处理的氨基磷脂可能是成肌细胞融合所必需的，但它们并不授予融合能力。
We have determined the asymmetric distribution of two aminophospholipids phosphatidylethanolamine and phosphatidylserine in the plasma membrane of chick embryo fibroblast and myoblasts. Right-side-out membrane preparations were incubated with two different amidating reagents, trinitrobenzenesulfonate and isethionylacetimidate, under nonpenetrating conditions. Inside-out membranes were incubated with trinitrobenzenesulfonate. In fibroblasts, the similar plateau values suggested that 35% of the phosphatidylethanolamine and 20% of the phosphatidylserine is externally disposed. These values agree with previous measurements on fibroblast plasma membranes. In myoblasts, however, labelling plateaux were achieved which suggested that 65% of the phosphatidylethanolamine and 45% of the phosphatidylserine is externally disposed. This represents a 2–3-fold increase in potentially fusogenic lipids on the external leaflet of the plasma membrane. This unique distribution of aminophospholipids in myoblasts extends through the stage of development during which myoblasts become competent to fuse and form myotubes in culture. Two inferences may be drawn from these results. First, the external concentration of aminophospholipids in myoblasts is enriched significantly over that of fibroblasts or erythrocytes. This orientation may contribute to its fusion competence. Second, although large amounts of externally disposed aminophospholipid may be necessary for myoblast fusion, they do not confer fusion competence.