Estellés A, Yokoyama M, Nothias F, Vincent J D, Glowinski J, Vernier P, Chneiweiss H
INSERM U114 and Chaire de Neuropharmacologie du Collège de France, 75231 Paris Cedex 05, France.
J Biol Chem. 1996 Jun 21;271(25):14800-6. doi: 10.1074/jbc.271.25.14800.
Specific phosphoproteins are targets of numerous extracellular signals received by astrocytes. One such target, which we previously described, is PEA-15, a protein kinase C substrate associated with microtubules. Two cDNAs differing in the length of their 3'-untranslated region (3'UTR) were cloned from a mouse astrocytic library. Accordingly, Northern blots revealed two transcripts (1.7 and 2.5 kilobase pairs) abundant brain regions but also found in peripheral tissues. PEA-15-deduced protein sequence (130 amino acids) shared no similarity with known proteins but is 96% identical to its human counterpart. In addition, several regions of the 3'UTR share more than 90% identity between mouse and human. Different potential regulatory sequences are found in the 3'UTR, which also completely includes the proto-oncogene MAT1. The high level of conservation of both the coding and the untranslated regions and the differential tissular distribution of the two transcripts of this major brain phosphoprotein suggest that not only the protein but also the 3'UTR of PEA-15 mRNA play a role in astrocytic functions.
特定的磷蛋白是星形胶质细胞接收到的众多细胞外信号的作用靶点。我们之前描述过的一个这样的靶点是PEA-15，一种与微管相关的蛋白激酶C底物。从一个小鼠星形胶质细胞文库中克隆出了两个3'-非翻译区（3'UTR）长度不同的cDNA。相应地，Northern印迹显示在脑区丰富但在外周组织中也能找到两种转录本（1.7和2.5千碱基对）。PEA-15推导的蛋白质序列（130个氨基酸）与已知蛋白质没有相似性，但与其人类对应物有96%的同一性。此外，3'UTR的几个区域在小鼠和人类之间有超过90%的同一性。在3'UTR中发现了不同的潜在调控序列，其还完全包含原癌基因MAT1。这种主要脑磷蛋白的编码区和非翻译区的高度保守以及两种转录本的不同组织分布表明，不仅PEA-15蛋白，而且其mRNA的3'UTR在星形胶质细胞功能中都发挥作用。
