Comparison of the expression of the src gene of Rous sarcoma virus in vitro and in vivo
Comparison of the expression of the src gene of Rous sarcoma virus in vitro and in vivo
复制标题
劳斯肉瘤病毒src基因体内外表达比较
作者：
B. Sefton;K. Beemon;T. Hunter
我们比较了几种劳斯肉瘤病毒的src基因的多肽产物，这些病毒是通过在核酸酶处理的网状细胞裂解物中体外翻译热变性的70S病毒粒子RNA产生的，与这些病毒转化的鸡细胞中存在的多肽产物。我们通过免疫沉淀的方法做到了这一点，使用出生时注射施密特-鲁平劳斯肉瘤病毒的兔血清。在体外翻译导致合成至少九种多肽，这些多肽似乎是由src基因编码的。它们的大小从17,000到60,000道尔顿不等。这些多肽是由A亚群和D亚群的Schmidt-Ruppin Rous肉瘤病毒和c亚群的Prague Rous肉瘤病毒的RNA在体外翻译产生的，在每种情况下，除了最小的17,000道尔顿多肽外，所有这些相关的多肽家族都可以沉淀。未观察到其他劳斯肉瘤病毒株的RNA翻译产生类似多肽的沉淀。由这三种劳斯肉瘤病毒毒株转化的细胞含有一种容易检测到的多肽p60src，与6万道尔顿的体外产物基本相同。除了一个例外，它们不含有大量的多肽，类似于可以由这些血清沉淀的较小的体外产物。由一组A亚群的施密特-鲁平劳斯肉瘤病毒转化的细胞确实含有39000道尔顿的多肽，通过肽图谱，该多肽与60000道尔顿的多肽相关，并且在大小上与可沉淀的体外产物相似。在转化细胞中存在的60000道尔顿多肽在合成后10至25分钟被磷酸化，代谢非常稳定，并且不是来源于前体多肽。所有含有p60src的转化细胞的免疫沉淀也含有一个80,000道尔顿的磷酸化蛋白。该多肽与p60src无关，根据肽图谱确定，它很可能是与p60src特异性相关的宿主细胞多肽。
We have compared the polypeptide products of the src gene of several strains of Rous sarcoma virus produced by in vitro translation of heat-denatured 70S virion RNA in the nuclease-treated reticulocyte lysate with those present in chick cells transformed by these viruses. We have done this by immunoprecipitation, using sera from rabbits injected at birth with Schmidt-Ruppin Rous sarcoma virus. In vitro translation results in the synthesis of at least nine polypeptides which appear to be encoded by the src gene. These range in size from 17,000 to 60,000 daltons. The sera from tumor-bearing rabbits precipitated these polypeptides arising from the in vitro translation of RNA from Schmidt-Ruppin Rous sarcoma virus of both subgroup A and subgroup D and from one stock of Prague Rous sarcoma virus of subgroup C. In each case, all of this family of related polypeptides could be precipitated except the smallest, the 17,000-dalton polypeptide. No precipitation of analogous polypeptides resulting from the translation of RNA from other strains of Rous sarcoma virus was observed. Cells transformed by these three strains of Rous sarcoma virus contain easily detectable amounts of a polypeptide, p60src, essentially identical to the 60,000-dalton in vitro product. With one exception, they do not contain significant amounts of polypeptides analogous to the smaller in vitro products which can be precipitated by these sera. Cells transformed by one stock of Schmidt-Ruppin Rous sarcoma virus of subgroup A did contain a 39,000-dalton polypeptide, which was related, by peptide mapping, to the 60,000-dalton polypeptide and was similar in size to a precipitable in vitro product. The 60,000-dalton polypeptide present in transformed cells appeared to be phosphorylated 10 to 25 min after its synthesis, metabolically very stable, and not derived from a precursor polypeptide. All immunoprecipitates from transformed cells which contained p60src also contained an 80,000-dalton phosphoprotein. This polypeptide is unrelated to p60src, as determined by peptide mapping, and may well be a host cell polypeptide which is specifically associated with p60src.