Ohara O, Ohara R, Yamakawa H, Nakajima D, Nakayama M
Laboratory of DNA Technology, Kazusa DNA Research Institute, Chiba, Japan.
Brain Res Mol Brain Res. 1998 Jun 15;57(2):181-92. doi: 10.1016/s0169-328x(98)00068-0.
We recently identified a gene which shows high similarity to the beta-spectrin gene but with a different chromosomal location from either of the two known beta-spectrin genes [T. Nagase, K.-I. Ishikawa, D. Nakajima, M. Ohira, N. Seki, N. Miyajima, A. Tanaka, H. Kotani, N. Nomura, O. Ohara, Prediction of the coding sequences of unidentified human genes: VII. The complete sequences of 100 new cDNA clones from brain which can code for large proteins in vitro, DNA Res. 4 (1997) 141-150]. In order to further characterize this new spectrin gene and its product, we isolated the rat counterpart of this gene and analyzed it in terms of its protein coding sequence, the tissue distribution of its mRNA and the product, and the regional distribution of the mRNA and the product in the brain. The results indicated that this gene was most abundantly transcribed in the brain and neurons were the predominant cell-type to express this gene. In particular, Purkinje cells were the richest in this gene product, and this new form of beta-spectrin was found more prominently in the dendrites than in the cell bodies. Since the expression pattern and the subcellular localization of this gene product were quiet distinct from those of the two beta-spectrin isoforms already characterized, this beta-spectrin gene would play an important role in neuronal membrane skeleton although it has been overlooked to date.
我们最近鉴定出一个基因，它与β-血影蛋白基因高度相似，但染色体定位与两个已知的β-血影蛋白基因均不同[T. 永濑、K.-I. 石川、D. 中岛、M. 大平、N. 关、N. 宫岛、A. 田中、H. 小谷、N. 野村、O. 大原，未鉴定的人类基因编码序列的预测：VII. 来自大脑的100个新的cDNA克隆的完整序列，这些克隆在体外可编码大蛋白，《DNA研究》4 (1997) 141 - 150]。为了进一步表征这个新的血影蛋白基因及其产物，我们分离了该基因的大鼠对应物，并从其蛋白质编码序列、mRNA及其产物的组织分布以及大脑中mRNA及其产物的区域分布方面进行了分析。结果表明，该基因在大脑中转录最为丰富，神经元是表达该基因的主要细胞类型。特别是，浦肯野细胞中这种基因产物最为丰富，并且这种新形式的β-血影蛋白在树突中比在细胞体中更为突出。由于该基因产物的表达模式和亚细胞定位与已表征的两种β-血影蛋白异构体明显不同，尽管迄今为止它一直被忽视，但这个β-血影蛋白基因可能在神经元膜骨架中发挥重要作用。
