Inhibitory effect of 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole on a protein kinase.
Inhibitory effect of 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole on a protein kinase.
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DOI：
10.1016/s0021-9258(17)42674-3
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发表时间：
1984-12
期刊：
影响因子：
--
通讯作者：
R. Zandomeni;R. Weinmann
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文献类型：
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作者：
R. Zandomeni;R. Weinmann
腺苷类似物5，6-二氯-1-β-D-呋喃核糖基苯并咪唑（DRB）抑制RNA聚合酶II的特异性体外转录起始。我们在这里报告说，DRB抑制蛋白激酶存在于HeLa细胞的提取物中，并不抑制其他蛋白激酶包含在同一提取物。受DRB影响的蛋白激酶不依赖环AMP，更喜欢酸性蛋白底物，如酪蛋白和胰高血糖素，并在磷酸转移酶反应中几乎与ATP一样有效地利用GTP作为磷酸供体。DRB敏感性蛋白激酶也受到多胺的刺激，并受到槲皮素和肝素的抑制。这种酶的生化和色谱特性与酪蛋白激酶II的特性一致。在HeLa细胞中，DRB能够抑制一些核蛋白的体内磷酸化。在HeLa细胞提取物，在体外磷酸化的几种蛋白质的[γ-32 P]GTP被DRB抑制。该蛋白激酶具有与先前报道的在全细胞提取物中通过RNA聚合酶II进行的特异性体外转录相同的DRB敏感性曲线（Zandomeni，R.，Mittleman，B.，Bunick，D.，阿克曼，S.，和Weinmann，R.等人（1982）Proc. Acad. Sci. U.S.A.79，3167-3170）。因此，我们认为，这种蛋白激酶介导的DRB抑制特异性RNA聚合酶II的转录在体内和体外。
The adenosine analog 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole (DRB) inhibits specific in vitro transcription initiation by RNA polymerase II. We report here that DRB inhibits a protein kinase present in an extract of HeLa cells and does not inhibit other protein kinases contained in the same extract. The protein kinase affected by DRB is cyclic AMP independent, prefers acidic protein substrates such as casein and phosvitin, and utilizes GTP as the phosphate donor almost as effectively as ATP in the phosphotransferase reaction. The DRB-sensitive protein kinase is also stimulated by polyamines and inhibited by quercitin and heparin. The biochemical and chromatographic properties of this enzyme correspond to those characteristic of casein kinase II. In HeLa cells, DRB is able to inhibit in vivo phosphorylation on some nuclear proteins. In HeLa cell extracts, in vitro phosphorylation of several proteins by [gamma-32P]GTP is inhibited by DRB. This protein kinase has a DRB sensitivity profile identical to the one previously reported for specific in vitro transcription by RNA polymerase II in a whole-cell extract (Zandomeni, R., Mittleman, B., Bunick, D., Ackerman, S., and Weinmann, R. (1982) Proc. Natl. Acad. Sci. U.S.A. 79, 3167-3170). Thus we suggest that this protein kinase mediates DRB inhibition of specific RNA polymerase II transcription in vivo and in vitro.