干扰素作用——依赖于ppp(A2'p)nA的核糖核酸酶的序列特异性

Interferon action--sequence specificity of the ppp(A2'p)nA-dependent ribonuclease.

作者信息

Wreschner D H, McCauley J W, Skehel J J, Kerr I M

出版信息

Nature. 1981 Jan 29;289(5796):414-7. doi: 10.1038/289414a0.

Abstract

The oligonucleotides pppA2'p5'A2'p5'A and related oligomers (2-5A) are synthesized by an enzyme that is widely distributed in a variety of cells, the activity of which varies with interferon treatment, growth and hormone status. Because significant amounts of 2-5A have recently been detected in interferon-treated cells, it has been suggested that the oligonucleotides may be involved in interferon action and in the control of cell metabolism. In both intact cells and cell-free systems 2-5A has been shown to activate a ribonuclease. We report here investigations of the sequence specificities of the 2-5A-dependent ribonucleases in extracts of rabbit reticulocytes, mouse ascites tumour cells and human lymphoblastoid cells in conditions of partial digestion using terminally labelled RNA substrates. The enzymes cleaved on the 3'-side of UN sequences to yield UpNp terminated products. Cleavage was observed predominantly at UA and UU sequences.

摘要

寡核苷酸三磷酸腺苷2′-5′-腺苷2′-5′-腺苷（pppA2′p5′A2′p5′A）及相关寡聚物（2-5A）由一种广泛分布于多种细胞中的酶合成，该酶的活性随干扰素处理、生长和激素状态而变化。由于最近在经干扰素处理的细胞中检测到大量的2-5A，有人提出这些寡核苷酸可能参与干扰素作用及细胞代谢的调控。在完整细胞和无细胞系统中，2-5A均已被证明可激活一种核糖核酸酶。我们在此报告，在使用末端标记RNA底物进行部分消化的条件下，对兔网织红细胞、小鼠腹水肿瘤细胞和人淋巴母细胞提取物中2-5A依赖性核糖核酸酶的序列特异性进行的研究。这些酶在UN序列的3′侧切割，产生以UpNp结尾的产物。切割主要发生在UA和UU序列处。