RNA TRANSCRIPTS INDUCED BY HYPERTHERMIA IN RODENT CELLS

原核细胞和真核细胞对环境应激的反应是通过 诱导多种应激相关蛋白。 在哺乳动物细胞中， 大多数表征良好的应激蛋白质组是由 体温过高 热休克蛋白的转录显著增加 这些基因中的几个已经从HeLa细胞中克隆出来， 其他实验室的细胞。 很可能是其他的转录 在哺乳动物细胞中也诱导了约10-20个基因， 在原核生物和低等真核生物中被诱导。 一种隔离方法 这样的转录本是为了富集热休克特异性cDNA， 与来自对照细胞的mRNA杂交扣除。 我们已经这样做了 与啮齿动物细胞，V79，我们还构建了一个cDNA文库， 热休克处理（HS）细胞。 我们的研究结果表明， HS在V79和CHO细胞系中诱导的转录是一个小的重复序列， 遗传因素 这个重复元素的转录本是 多聚腺苷酸化，如大多数mRNA种类。 这种重复的转录 先前已经发现，在转化的啮齿动物中， 细胞和啮齿动物肿瘤细胞。 令人感兴趣的是，HS蛋白是 通常在转化细胞中升高。 该元件的序列分析 揭示了一个区域与HS启动子非常相似 果蝇的共有序列 这种基因的诱导不是 非特异性，因为X射线或紫外线辐射的等毒性不会增加 转录。 我们还分离了大多数主要的cDNA克隆， 中国仓鼠细胞热休克蛋白基因。

Prokaryotic and eukaryotic cells respond to enviromental stress by the induction of a variety of stress-related proteins. In mammalian cells, the most well characterized group of stress proteins are induced by hyperthermia. Transcription of heat shock proteins increases markedly after hyperthermia and several of these genes have been cloned from HeLa cells in other laboratories. It is likely that transcription of other genes is also induced in mammalian cells since approximately 10-20 genes are induced in prokaryotes and lower eukaryotes. One approach to isolate such transcripts is to enrich for heat shock specific cDNA's by hybridization subtraction with mRNA from control cells. We have done this with rodent cells, V79, and we have also constructed a cDNA library from heat shock treated (HS) cells. Our results indicate that the most abundant transcript induced by HS in V79 and CHO cell lines is a small repetitive genetic element. The transcripts of this repetitive element are polyadenylated as are most mRNA species. Transcription of this repetitive element has previously been found to be increased in transformed rodent cells and rodent tumor cells. It is of interest that HS proteins are usually elevated in transformed cells. Sequence analysis of this element reveals that a region has very close similarities to the HS promoter consensus sequence of Drosophilia. The induction of this gene is not non-specific since equitoxic of x-rays or UV-radiation do not increase transcription. We have also isolated cDNA clones for most of the major heat shock protein genes in Chinese hamster cells.