ADENOSINE DIPHOSPHORIBOSYLATION OF AMINOACYL TRANSFERASE-II BY DIPHTHERIA TOXIN
ADENOSINE DIPHOSPHORIBOSYLATION OF AMINOACYL TRANSFERASE-II BY DIPHTHERIA TOXIN
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DOI：
10.1101/sqb.1969.034.01.069
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发表时间：
1969-01-01
期刊：
影响因子：
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通讯作者：
HAYAISHI, O
中科院分区：
文献类型：
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作者：
HONJO, T;NISHIZUKA, Y;HAYAISHI, O
Strauss和Hendee(1959)，Kato和Pappenhelmet(1960)和Kato(1962)已经证明白喉毒素在无CEU的系统中以及在培养细胞中抑制哺乳动物的蛋白质合成。Collier和Pappenheimer(1964)随后表明，NAD是从HeLa细胞和兔网织红细胞获得的无细胞系统中蛋白质合成的绝对抑制所必需的。最近，Collier(1967i)和Goor和Pappenheimer(1967)证明了毒素特异性地灭活氨基酰转移酶II，这是一种在信使RNA的指导下将氨基酸组装成多肽链的可溶性因子。进一步证明，足够浓度的烟酰胺可以防止或逆转转移酶II的失活(Goor等人，1967)。在本文中，将简要提供证据表明，白喉毒素将NAD的ADP核糖部分转移到转移酶II，导致这一特殊的‘酶同时失活。化学计量的烟酰胺同时被释放，反应是可逆的。与转移酶II相关的核糖体依赖的GTPase活性也将被这种ADP-核糖化反应显示失活。因此，这些结果可以阐明白喉毒素的作用方式，这是本书前面的论文(Collier和Traugh，以及Gill，Pappenheimer和Baseman)所介绍的。在目前的研究中，多肽合成的活性是通过测量14C-苯丙氨酰-tRNA的多U-定向掺入不溶于热三氯乙酸的物质中的放射性来测定的(Honjo等人，1968)。对Skogerson和Moldave(1967)的方法稍作改进，从大鼠肝脏中分离纯化了两种辅助因子氨酰转移酶I和II，并用磷酸钙凝胶和羟基磷灰石柱层析法进一步纯化。这些纯化的因子是完全不相互作用的。大鼠肝组织核糖体的制备
Strauss and Hendee (1959), Kato and Pappenhelmet (1960) and Kato (1962) have shown that diphtheria toxin inhibits mammalian protein synthesis in ceU-free systems as well as in cultured cells. Collier and Pappenheimer (1964) have shown subsequently that NAD is absolutely required for this inhibition of protein synthesis in cell-free systems obtained from HeLa cells and from rabbit reticulocytes. More recently Collier (1967i, and Goor and Pappenheimer (1967) have demonstrated that toxin specifically inactivates aminoacyl transferase II, one of the soluble factors which assemble amino acids into a polypeptide chain as directed by messenger RNA. It has been further shown that the inactivation of transferase II can be prevented or reversed by the presence of a sufficient concentration of nicotinamide (Goor et al., 1967). In this article, evidence will be briefly presented indicating that diphtheria toxin transfers the ADP-ribose portion of NAD to transferase II, resulting in a concurrent inactivation of this particular'enzyme. A stoichiometric amount of nicotinamide is released simultaneously and the reaction is reversible. The ribosome-dependent GTPase activity associated with transferase II will also be shown to be inactivated by this ADP-ribosylation reaction. These results, therefore, may clarify the mode of action of diphtheria toxin which has been introduced by the preceding papers in this volume (Collier and Traugh, and Gill, Pappenheimer, and Baseman). In the present studies the activity of polypeptide synthesis was assayed by measuring the poly U-directed incorporation of radioactivity from 14C-phenylalanyl-tRNA into material insoluble in hot trichloracetic acid as described previously (Honjo et al., 1968). The complementary factors, aminoacyl transferases I and II, were purified from rat liver by a slight modification of the method of Skogerson and Moldave (1967), and further purified by calcium phosphate gel and hydroxylapatite column chromatography. These purified factors were completely free of each other. Rat liver ribosomes were prepared by the method of