Zehavi-Willner T, Lane C
Cell. 1977 Jul;11(3):683-93. doi: 10.1016/0092-8674(77)90085-x.
The Xenopus oocyte can be used to study the nature and specificity of the translational and post-translational systems of a normal living cell. We describe experiments combining messenger RNA microinjection and subcellular fractionation. Total Xenopus liver RNA directs the synthesis of albumin and vitellogenin contained within membrane vesicles; similarly, guinea pig mammary gland mRNA codes for membrane-bound protease-resistant milk proteins. In contrast, iodinated albumin protein injected into oocytes remains in the supernatant fraction, as does globin made on mRNA. The information encoded in the albumin messenger is therefore sufficient to specify synthesis of a membrane-bound product; moreoever, this highly efficient coupled translation-processing system may be of use in the study of the transfer of newly made proteins across membranes. A significant proportion (up to 20%) of newly made oocyte proteins enter a light membrane fraction, and many remain there. We speculate that these vesicles represent part of an important storage system.
非洲爪蟾卵母细胞可用于研究正常活细胞的翻译及翻译后系统的性质和特异性。我们描述了将信使核糖核酸显微注射与亚细胞分级分离相结合的实验。非洲爪蟾肝脏总核糖核酸指导膜泡内所含白蛋白和卵黄蛋白原的合成；同样，豚鼠乳腺信使核糖核酸编码与膜结合的抗蛋白酶乳蛋白。相比之下，注入卵母细胞的碘化白蛋白蛋白仍留在上清液部分，由信使核糖核酸合成的珠蛋白也是如此。因此，白蛋白信使中编码的信息足以指定合成一种与膜结合的产物；此外，这种高效的偶联翻译加工系统可能有助于研究新合成蛋白质跨膜转运。相当一部分（高达20%）新合成的卵母细胞蛋白进入轻膜部分，并且许多蛋白会留在那里。我们推测这些囊泡代表了一个重要储存系统的一部分。
