Trachsel H, Sonenberg N, Shatkin A J, Rose J K, Leong K, Bergmann J E, Gordon J, Baltimore D
Proc Natl Acad Sci U S A. 1980 Feb;77(2):770-4. doi: 10.1073/pnas.77.2.770.
It was previously shown that the poliovirus-induced inhibition of translation of capped mRNAs can be reversed by a protein found in preparations of the eukaryotic initiation factor eIF-4B [Rose, J. K., Trachsel, H., Leong, K. & Baltimore, D. (1978) Proc. Natl. Acad. Sci. USA 75, 2732--2736]. This "restoring factor" has now been purified from a high-salt wash of rabbit reticulocyte ribosomes by taking advantage of its tight association with factor eIF-3 at low salt concentrations. It did not copurify with the major Mr 80,000 polypeptide of eIF-4B preparations but did copurify with a Mr 24,000 polypeptide previously shown to bind to the cap structures of mRNAs [Sonenberg, N., Rupprecht, K. M., Hecht, S. M. & Shatkin, A. J. (1979) Proc. Natl. Acad. Sci. USA 76, 4345--4349]. Both the electrophoretic mobility and the tryptic peptide pattern of the restoring factor were indistinguishable from those of the cap-binding protein, and the restoring factor could be crosslinked to the 5'-terminal cap on mRNA. Thus, is appears that poliovirus inhibits cellular protein synthesis by inactivation of some crucial property of the cap-binding protein.
先前的研究表明，脊髓灰质炎病毒对加帽mRNA翻译的抑制作用可被真核起始因子eIF-4B制剂中发现的一种蛋白质逆转[罗斯，J.K.，特拉舍尔，H.，梁，K.和巴尔的摩，D.（1978年）《美国国家科学院院刊》75，2732 - 2736]。现在，利用其在低盐浓度下与因子eIF-3的紧密结合，已从兔网织红细胞核糖体的高盐洗脱物中纯化出这种“恢复因子”。它没有与eIF-4B制剂中主要的80,000道尔顿多肽共纯化，但与先前显示能结合mRNA帽结构的24,000道尔顿多肽共纯化[索嫩贝格，N.，鲁普雷希特，K.M.，赫希特，S.M.和沙金，A.J.（1979年）《美国国家科学院院刊》76，4345 - 4349]。恢复因子的电泳迁移率和胰蛋白酶肽谱与帽结合蛋白的电泳迁移率和胰蛋白酶肽谱无法区分，并且恢复因子可与mRNA上的5'-末端帽交联。因此，似乎脊髓灰质炎病毒通过使帽结合蛋白的某些关键特性失活来抑制细胞蛋白质合成。
