Topographical localization of the receptors for luteinizing hormone-releasing hormone on the surface of dissociated pituitary cells.
Topographical localization of the receptors for luteinizing hormone-releasing hormone on the surface of dissociated pituitary cells.
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DOI：
10.1083/jcb.75.2.528
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发表时间：
1977-11
期刊：
影响因子：
--
通讯作者：
Gregory H
中科院分区：
文献类型：
--
作者：
Hopkins CR;Gregory H
下丘脑促黄体生成素释放激素（LHRH）的衍生物已被耦合到铁蛋白和凝胶色谱纯化的共轭物。在体外刺激垂体细胞分泌促黄体激素的能力方面，缀合物具有与天然肽相同的效力和特异性。将短期培养的分离垂体细胞用甲醛轻轻固定，然后与偶联物孵育，电子显微镜检查显示铁蛋白颗粒均匀分布在促性腺激素细胞的游离细胞表面。这种结合似乎对LHRH受体是特异性的，因为它被10倍过量的天然肽阻止。除促性腺激素细胞外，一些促生长激素和促甲状腺激素细胞在类似条件下在其游离表面结合共轭物。如果活细胞与缀合物一起孵育15分钟，则结合的缀合物聚集，然后集中在细胞表面的一个局部区域。在这一区域，它位于紧挨在单核高尔基复合体上方，质膜经常内陷的方式表明，绑定，聚集的共轭物是通过内吞内化。
A derivative of the hypothalamic peptide luteinizing hormone-releasing hormone (LHRH) has been coupled to ferritin and the conjugate purified by gel chromatography. In its ability to stimulate the secretion of luteinizing hormone from pituitary cells in vitro, the conjugate has the same potency and specificity as the native peptide. When dissociated pituitary cells maintained in short-term culture are lightly fixed with formaldehyde and then incubated with the conjugate, examination in the electron microscope shows an even distribution of ferritin particles over the free cell surface of the gonadotrophin cells. This binding appears to be specific for the LHRH receptor since it is prevented by a 10-fold excess of native peptide. In addition to the gonadotrophin cells, some somatotrophin and thyrotrophin cells bind conjugate on their free surfaces under similar conditions. If living cells are incubated with the conjugate for 15 min, the bound conjugate becomes aggregated and then concentrated in one localized area of the cell surface. In this area, which lies immediately above the juxtanuclear Golgi complex, the plasma membrane is frequently invaginated in a manner which suggests that the bound, aggregated conjugate is internalized by endocytosis.