INDUCTION & SUPPRESSION OF TRANSFORMATION BY VIRAL & TUMOR-DERIVED ONCOGENES

利用温度敏感型小鼠肉瘤病毒转化大鼠 成纤维细胞和抗莫斯回复突变细胞系（F-1），我们有 检测了丝氨酸/苏氨酸激酶v-mos癌基因的能力， 激活丝裂原相关蛋白激酶的上游激活因子， 转化细胞 与MKK-1一样，MKK-2在细胞内被组成性激活。 莫斯转化细胞。 在表达V-MOS的细胞中， MKK-1和MKK-2均以温度依赖性方式在 1小时转换到允许温度。 c-raf-1也是 在mos转化的细胞中组成性激活，但不被激活 直到极移后4小时，这表明它的激活可能是一个 MOS的二次效应 组成型活性MKK-1和MKK-2均 转化正常大鼠成纤维细胞和F-1回复突变体，与 假设MKK的mos激活可能是必要的， 足以用于大鼠成纤维细胞的MOS诱导转化。 小鼠逆转录病毒显示出非常低的不正确的 多聚腺苷酸化导致通读转录物。 我们产生 药物可选择的鼠病毒含有突变的.. AATAAA.. 多聚腺苷酸化信号，并显示大多数细胞感染 这些病毒表达含有高达1.2kb的通读转录物 细胞衍生的序列。 序列分析显示， 转录物由独特的和重复的宿主衍生序列组成。 条件培养基中存在的生长和附着促进活性 通过SFDH，一种在无血清培养基中生长的NIH 3 T3细胞系， 可制粒（150，000 g，24小时），伴有囊泡样 结构，并且可以在Superose-12柱上在6 M尿素中分馏。

Using temperature-sensitive murine sarcoma virus transformed rat fibroblasts and a mos-resistant revertant cell line (F-1), we have examined the ability of the serine/threonine kinase v-mos oncogene to activate the upstream activators of mitogen-associated protein kinase in transformed cells. Like MKK-1, MKK-2 is constitutively activated in mos-transformed cells. In cells which express v-mos in a temperature-dependent manner both MKK-1 and MKK-2 are activated within 1 hour of a shift to the permissive temperature. c-raf-1 is also constitutively activated in mos- transformed cells, but is not activated until 4 hours after the shift, suggesting its activation may be a secondary effect of mos. Constitutively-active MKK-1 and MKK-2 both transform normal rat fibroblasts and the F-1 revertant, consistent with the hypothesis that mos activation of MKK may be both necessary and sufficient for mos-induced transformation of rat fibroblasts. Murine retroviruses show a very low frequency of incorrect polyadenylation leading to read-through transcripts. We generated drug-selectable murine viruses containing mutations in the ..AATAAA.. polyadenylation signal and showed that the majority of cells infected by these viruses expressed read-through transcripts containing up to 1.2 kb of cell-derived sequences. Sequence analysis reveals that read-through transcripts consist of both unique and repetitive host-derived sequences. The growth and attachment-promoting activity present in media conditioned by SFDH, an NIH3T3 cell line which grows in serum-free media, is pelletable (150,000 g, 24 hours), associated with vesicle-like structures, and can be fractionated in 6M urea on a Superose-12 column.