IMMUNOGOLD LOCALIZATION OF INOSITOL 1,4,5-TRISPHOSPHATE (INSP3) RECEPTOR IN MOUSE CEREBELLAR PURKINJE-CELLS USING 3 MONOCLONAL-ANTIBODIES
IMMUNOGOLD LOCALIZATION OF INOSITOL 1,4,5-TRISPHOSPHATE (INSP3) RECEPTOR IN MOUSE CEREBELLAR PURKINJE-CELLS USING 3 MONOCLONAL-ANTIBODIES
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DOI：
10.1247/csf.15.163
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发表时间：
1990-06-01
影响因子：
1.5
通讯作者：
TASHIRO, Y
中科院分区：
文献类型：
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作者：
OTSU, H;YAMAMOTO, A;TASHIRO, Y
用免疫胶体金技术，用单抗10A6、4C11和18A10研究了InsP3受体在小鼠小脑浦肯野细胞的超微结构定位。这三种抗体的表位在光面内质网(ER)(尤其是扁平的光面内质网、隐池和棘器的堆叠)、粗糙的ER和外核膜上大量检测到，而在质膜、突触密度、线粒体和高尔基体上均未检测到。不仅与受体N-端区结合的单抗4C11和10A6，而且与受体C-端区结合的18A10也定位在内质膜的细胞质表面。这表明InsP3受体的C末端位于内质网的胞质表面。我们注意到，金颗粒通常定位在光滑内质网细胞质表面的模糊结构上，这可能与兰尼定受体的足部结构相对应。在尼氏小体中，金颗粒不仅存在于ER膜上，而且存在于粗大ER池之间的胞质基质中。我们认为，尼氏小体的特殊结构是由粗大的内质网平行的池组成，在池单元之间夹着许多游离的多聚核糖体，这是由于InsP3受体等主要蛋白质主要是在游离的多聚核糖体上合成的，只有在生物合成的后期才成为膜结合体。
Ultrastructural localization of InsP3 receptor in mouse cerebellar Purkinje cells was investigated by immunogold technique using three monoclonal antibodies (mab 10A6, 4C11 and 18A10). The epitopes of the three antibodies were numerously detected on the smooth endoplasmic reticulum (ER) (especially, on the stacks of flattened smooth ER, subsurface cisterns and spine apparatus), scantily on the rough ER and on the outer nuclear membrane, but were not detectable on either the plasmalemma, synaptic densities, mitochondria or Golgi apparatus. Not only mab 4C11 and 10A6 which bind to the N-terminal region of the receptor but also 18A10 which binds to the C-terminal region were localized on the cytoplasmic surface of the ER membranes. This indicates that the C terminus of InsP3 receptor is localized on the cytoplasmic surface of the ER. We noticed that gold particles are usually localized on the fuzzy structure of the cytoplasmic surface of smooth ER, which is suggested to correspond to the feet structure of the ryanodine receptor. In the Nissl body, gold particles were found not only on the ER membranes but also in the cytoplasmic matrix between the rough ER cisterns. We suggest that the peculiar structure of Nissl body, which is composed of parallel cisterns of rough ER, sandwiching a number of free polyribosomes between the cisternal elements, is due to the fact that the major proteins like InsP3 receptor are synthesized mostly on the free polyribosomes and become membrane bound only at the later stage of the biosynthesis.