IDENTIFICATION OF PROTEIN PRODUCTS ENCODED BY THE PROTOONCOGENE INT-1
IDENTIFICATION OF PROTEIN PRODUCTS ENCODED BY THE PROTOONCOGENE INT-1
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DOI：
10.1128/mcb.7.11.3971
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发表时间：
1987-11-01
影响因子：
5.3
通讯作者：
VARMUS, HE
中科院分区：
文献类型：
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作者：
BROWN, AMC;PAPKOFF, J;VARMUS, HE
原癌基因int-1在小鼠乳腺肿瘤病毒诱导的肿瘤中被前病毒DNA的相邻插入激活，并在某些乳腺上皮细胞系中具有转化活性。该基因通常在妊娠中期胚胎的中枢神经系统和成年睾丸中表达。我们提出了针对合成int-1肽的抗体，并使用这些抗体来鉴定用表达int-1的逆转录病毒载体转染或感染的细胞中该基因的蛋白质产物。四种蛋白质种类的36，000，38，000，40，000，和42，000先生免疫沉淀的抗体对两种不同的int-1肽，并不存在于对照细胞。V8蛋白酶的部分降解表明，这四个物种在结构上彼此相关，并在体外合成的int-1多肽。用衣霉素处理细胞，除了36，000-Mr的物质外，其他所有物质都没有出现，这表明迁移较慢的形式是糖基化衍生物。非糖基化的36，000-Mr物种在聚丙烯酰胺凝胶中的迁移速度比INT-1的体外翻译产物更快，并且可能经历了氨基末端信号肽的裂解。
The proto-oncogene int-1 is activated by adjacent insertions of proviral DNA in mouse mammary tumor virus-induced tumors and has transforming activity in certain mammary epithelial cell lines. The gene is normally expressed in the central nervous system of mid-gestational embryos and in the adult testis. We raised antibodies against synthetic int-1 peptides and used these to identify protein products of the gene in cells transfected or infected with retroviral vectors expressing int-1. Four protein species of 36,000, 38,000, 40,000, and 42,000 Mr were immunoprecipitated by antibodies against two different int-1 peptides and were not present in control cells. Partial degradation with V8 protease showed the four species to be structurally related to each other and to int-1 polypeptide synthesized in vitro. Treatment of the cells with tunicamycin prevented the appearance of all but the 36,000-Mr species, suggesting that the slower-migrating forms are glycosylated derivatives. The unglycosylated 36,000-Mr species migrated faster in polyacrylamide gels than the in vitro translation product of int-1 and has probably undergone cleavage of an amino-terminal signal peptide.