Sher N, Edelbaum O, Barak Z, Grafi G, Stram Y, Raber J, Sela I
Virus Laboratory, Hebrew University of Jerusalem, Faculty of Agriculture, Rehovot, Israel.
Virus Genes. 1990 Jun;4(1):27-39. doi: 10.1007/BF00308563.
Several reports have indicated that tobacco carries an enzyme (APE) that, in the presence of poly (rI):(rC), polymerizes ATP to oligoadenylates. This paper demonstrates that the tobacco APE system comprises several proteins (estimated sizes: 32, 42, 67, and 84 +/- 10% kD). Only one of these proteins (the "67-kD" form) binds to poly (rI):(rC). This APE form has been purified by affinity chromatography on a synthetic ds-RNA column. Four tobacco proteins, including the purified one, crossreact with antibodies against the human enzyme, 2'-5' A synthetase. The ATP-binding capacity of some of these proteins has also been demonstrated. The amount of plant oligoadenylates obtained by polymerizing ATP with the purified APE form allows, for the first time, their direct analysis by TLC. The TLC analysis indicated that the oligomer produced by APE is not identical to the 2'-5' oligoadenylate. The appearance of the 2'-5' A-related proteins correlates with the build up of TMV infection, and the pattern of their stimulation and turnover was established. Nucleic acid hybridization indicates homology of tobacco DNA and RNA sequences with cloned cDNA of the human 2'-5' A synthetase gene. The stimulation in tobacco, upon TMV infection, of mRNA species homologous to the above human cDNA has been demonstrated. The analogy between the plant and the human system is discussed.
几份报告指出，烟草含有一种酶（APE），在聚（rI）：（rC）存在的情况下，它能将ATP聚合成寡腺苷酸。本文证明烟草APE系统由几种蛋白质组成（估计大小：32、42、67和84±10%kD）。这些蛋白质中只有一种（“67-kD”形式）与聚（rI）：（rC）结合。这种APE形式已通过在合成双链RNA柱上的亲和层析纯化。包括纯化后的蛋白质在内的四种烟草蛋白质与针对人类酶2'-5'A合成酶的抗体发生交叉反应。还证明了其中一些蛋白质的ATP结合能力。通过将ATP与纯化的APE形式聚合得到的植物寡腺苷酸的量首次使得能够通过薄层层析对其进行直接分析。薄层层析分析表明，APE产生的寡聚物与2'-5'寡腺苷酸不同。与2'-5'A相关的蛋白质的出现与烟草花叶病毒感染的积累相关，并且确定了它们的刺激和周转模式。核酸杂交表明烟草DNA和RNA序列与人类2'-5'A合成酶基因的克隆cDNA具有同源性。已经证明，在烟草花叶病毒感染后，烟草中与上述人类cDNA同源的mRNA种类受到刺激。本文讨论了植物和人类系统之间的相似性。
