Peng S B, Crider B P, Xie X S, Stone D K
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235.
J Biol Chem. 1994 Jun 24;269(25):17262-6.
The cDNA encoding the 116-kDa polypeptide of the bovine brain vacuolar-type proton translocating ATPases has been cloned and sequenced. One of five clones differed from all others in that it contained an 18-base pair deletion within the coding region, whereas it was identical to the other clones in overlapping coding and noncoding regions, indicating that this heterogeneity arises through an alternative splicing mechanism. By conventional Northern analysis, only one 4.1-kilobase mRNA was identified in bovine brain, heart, kidney, liver, and spleen. However, a polymerase chain reaction-based analysis revealed two species of mRNA with a tissue-specific distribution. Type I, containing the 18-base pair insert, was found in brain, whereas the truncated (Type II) form was found in all tissues examined. Similar tissue distributions of rat mRNA were observed. The deletion site accounting for this variability occurs within a predicted protease sensitivity motif (PEST site), suggesting that differences in the biological half-life of the two 116-kDa isoforms may exist.
编码牛脑液泡型质子转运ATP酶116 kDa多肽的cDNA已被克隆和测序。五个克隆中的一个与其他所有克隆不同，因为它在编码区内有一个18碱基对的缺失，而在重叠的编码区和非编码区它与其他克隆相同，这表明这种异质性是通过可变剪接机制产生的。通过传统的Northern分析，在牛脑、心脏、肾脏、肝脏和脾脏中仅鉴定出一种4.1千碱基的mRNA。然而，基于聚合酶链反应的分析揭示了两种具有组织特异性分布的mRNA。含有18碱基对插入片段的I型在脑中发现，而截短的（II型）形式在所有检测的组织中发现。观察到大鼠mRNA有类似的组织分布。导致这种变异性的缺失位点出现在一个预测的蛋白酶敏感基序（PEST位点）内，这表明两种116 kDa同工型的生物学半衰期可能存在差异。
