PHOSPHATIDYLINOSITOL IS INVOLVED IN THE MEMBRANE ATTACHMENT OF NCAM-120, THE SMALLEST COMPONENT OF THE NEURAL CELL-ADHESION MOLECULE
PHOSPHATIDYLINOSITOL IS INVOLVED IN THE MEMBRANE ATTACHMENT OF NCAM-120, THE SMALLEST COMPONENT OF THE NEURAL CELL-ADHESION MOLECULE
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DOI：
10.1002/j.1460-2075.1986.tb04526.x
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发表时间：
1986-10-01
期刊：
影响因子：
11.4
通讯作者：
GORIDIS, C
中科院分区：
文献类型：
--
作者：
HE, HT;BARBET, J;GORIDIS, C
啮齿动物神经细胞粘附分子（NCAM）由三种糖蛋白组成，其Mr分别为180，000、140，000和120，000。Mr 120，000蛋白（NCAM-120）已被证明以膜结合和可溶形式存在，但其膜缔合和释放的性质仍然不清楚。我们在这里表明，磷脂酰肌醇特异性磷脂酶C（PI-PLC），但不是一个磷脂酶C的不同特异性，释放了相当大的比例NCAM-120从脑细胞膜和溶解几乎定量NCAM-120存在于表面的C6星形胶质细胞。PI-PLC效应是高度选择性的，因为仅一种其它蛋白质种类可检测地从C6细胞释放。这些结果表明，NCAM-120被共价结合的磷脂酰肌醇或密切相关的脂质以类似于来自真核细胞的几种其他表面蛋白的方式保持在膜中。NCAM以一种可以通过高度选择性机制从细胞表面释放的形式存在，增加了调节和控制细胞-细胞粘附的额外可能性。
The rodent neural cell adhesion molecule (NCAM) consists of three glycoproteins with Mr of 180,000, 140,000 and 120,000. The Mr 120,000 protein (NCAM-120) has been shown to exist in membrane-bound and soluble forms but the nature of its membrane association and release has remained obscure. We show here that phosphatidylinositol-specific phospholipase C (PI-PLC), but not a phospholipase C of different specificity, releases a substantial proportion of NCAM-120 from brain membranes and solubilizes almost quantitatively NCAM-120 present at the surface of C6 astroglial cells. The PI-PLC effect was highly selective since only one other protein species was detectably released from C6 cells. These results suggest that NCAM-120 is held in the membrane by covalently bound phosphatidylinositol or a closely related lipid in a way similar to several other surface proteins from eukaryotic cells. The presence of NCAM in a form which can be released from the cell surface by a highly selective mechanism raises additional possibilities for modulation and control of cell-cell adhesion.