Localization of calmodulin in rat cerebellum by immunoelectron microscopy.
Localization of calmodulin in rat cerebellum by immunoelectron microscopy.
复制标题
通过免疫电子显微镜将钙调蛋白定位在大鼠小脑中。
DOI：
10.1083/jcb.85.2.473
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发表时间：
1980-05
影响因子：
7.8
通讯作者：
Means, A R
中科院分区：
文献类型：
--
作者：
Lin, C T;Dedman, J R;Brinkley, B R;Means, A R
钙调蛋白是一种多功能 Ca(++) 结合蛋白，存在于所有真核细胞中。我们使用 Fab-过氧化物酶缀合物技术通过免疫电子显微镜研究了该蛋白质在大鼠小脑中的分布。在浦肯野细胞体和颗粒细胞体中，发现钙调蛋白反应产物位于游离核糖体上以及附着在粗面内质网 (RER) 和核膜上的核糖体上。在 RER 池或高尔基体中未观察到钙调蛋白。在所使用的条件下，钙调蛋白似乎没有浓缩在细胞的可溶部分中。相反，可以看到过氧化物酶反应产物与高尔基体膜、平滑内质网（SER）以及细胞体和神经元突起的质膜相关。在神经元树突中，钙调蛋白似乎集中在 SER 膜、小囊泡和线粒体上。此外，在无定形材料中观察到颗粒状钙调蛋白。在突触连接处，观察到大量钙调蛋白附着在突触后膜的内表面，而在突触前膜或囊泡中观察到很少量。这些观察结果表明，钙调蛋白在核糖体上合成并排出到细胞质中，然后与各种细胞内膜结合。钙调蛋白似乎也通过神经元过程转运至突触后膜。钙调蛋白定位于突触后膜表明该蛋白可能介导突触连接处的钙效应，因此可能在神经传递的调节中发挥作用。
Calmodulin, a multifunctional Ca(++)-binding protein, is present in all eucaryotic cells. We have investigated the distribution of this protein in the rat cerebellum by immunoelectron microscopy using a Fab-peroxidase conjugate technique. In Purkinje and granular cell bodies, calmodulin reaction product was found localized both on free ribosomes and on those attached to rough endoplasmic reticulum (RER) and the nuclear envelope. No calmoduline was observed in the cisternae of RER or the Golgi apparactus. Calmodulin did not appear to be concentrated in the soluble fraction of the cell under the conditions used. Rather, peroxidase reaction product could be seen associated with membranes of the Golgi apparatus the smooth endoplasmic reticulum (SER), and the plasma membrane of both cell bodies and neuronal processes. In the neuronal dendrites, calmodulin appeared to be concentrated on membranes of the SER, small vesicles, and mitochondria. Also, granular calmodulin was observed in the amorphous material. In the synaptic junction, a large amount of calmodulin was seen attached to the inner surface of the postsynaptic membrane, whereas very little was observed in the presynaptic membrane or vesicles. These observations suggest that calmodulin is synthesized on ribosomes and discharged into the cytosol, and that it then becomes associated with a variety of intracellular membranes. Calmodulin also seems to be transported via neuronal processes to the postsynaptic membrane. Calmodulin localization at the postsynaptic membrane suggests that this protein may mediate calcium effects at the synaptic junction and, thus, may play a role in the regulation of neurotransmission.