Solà C, Tusell J M, Serratosa J
Department of Pharmacology and Toxicology, Institut d'Investigacions Biomèdiques de Barcelona, CSIC, Spain.
Neuroscience. 1996 Nov;75(1):245-56. doi: 10.1016/0306-4522(96)00214-x.
Calmodulin is a major calcium-binding protein in the mammalian brain, playing an important role in neuronal cell function. Its amino acid sequence is highly conserved and the protein is encoded by multiple genes. In the mouse brain, as well as in the rat and the human brain, three different genes have been detected for calmodulin, CaM I, CaM II and CaM III, all of which encode an identical protein. We studied the pattern of expression of the three calmodulin genes and the pattern of calmodulin distribution in the mouse brain by in situ hybridization histochemistry and immunohistochemistry. We found that calmodulin messenger RNAs from the three calmodulin genes were widely expressed in the mouse brain. Nevertheless, there were differences in their patterns of distribution. In general, all calmodulin messenger RNAs were preferentially distributed in hippocampus, cerebral cortex and cerebellar cortex, and CaM II messenger RNA also in caudate-putamen. However, all messenger RNAs showed clearly differentiated patterns of distribution in the hippocampus and the cerebellar cortex. Calmodulin immunoreactivity was present in all cells so far examined. Immunostaining was observed both in the cell nucleus, where it was especially strong, and in the cytoplasm. Our results suggest that the three calmodulin genes are differentially regulated in the mouse brain and also that, although all calmodulin genes have a basal expression, precise regulation of calmodulin levels might be attained through the different contribution of the three calmodulin genes.
钙调蛋白是哺乳动物大脑中一种主要的钙结合蛋白，在神经元细胞功能中发挥着重要作用。其氨基酸序列高度保守，该蛋白由多个基因编码。在小鼠脑以及大鼠和人类脑中，已检测到三种不同的钙调蛋白基因，即CaM I、CaM II和CaM III，它们均编码同一种蛋白。我们通过原位杂交组织化学和免疫组织化学研究了小鼠脑中三种钙调蛋白基因的表达模式以及钙调蛋白的分布模式。我们发现，来自这三种钙调蛋白基因的钙调蛋白信使核糖核酸在小鼠脑中广泛表达。然而，它们的分布模式存在差异。一般来说，所有钙调蛋白信使核糖核酸都优先分布于海马体、大脑皮层和小脑皮层，CaM II信使核糖核酸还分布于尾状核-壳核。然而，所有信使核糖核酸在海马体和小脑皮层中均呈现出明显不同的分布模式。在迄今为止所检测的所有细胞中均存在钙调蛋白免疫反应性。在细胞核（免疫染色尤其强烈）和细胞质中均观察到了免疫染色。我们的结果表明，在小鼠脑中三种钙调蛋白基因受到不同的调控，并且尽管所有钙调蛋白基因都有基础表达，但通过三种钙调蛋白基因的不同贡献可能实现对钙调蛋白水平的精确调控。
