Galli G, Hofstetter H, Stunnenberg H G, Birnstiel M L
Cell. 1983 Oct;34(3):823-8. doi: 10.1016/0092-8674(83)90539-1.
When the cloned h22 histone gene repeat unit of the sea urchin Psammechinus miliaris is injected into the frog oocyte nucleus, transcription initiates faithfully in the promoter region of the H3 gene, but transcription termination or RNA processing to yield genuine H3 mRNA 3' ends is very inefficient. The generation of 3' ends can be enhanced by the injection of a small sea urchin poly (A)- RNA into the oocyte cytoplasm one day prior to injection of the histone gene repeat unit. This RNA is approximately 60 nucleotides in length and appears to be present in relatively low abundance in embryos of both Psammechinus and Paracentrotus. RNA extracted from a nuclear DEAE fraction, previously shown to complement the lesion in H3 gene expression, also causes the appearance of true 3' ends of H3 mRNA. Furthermore, RNA extracted from our 12S "termination" factor includes an RNA species comigrating with the 60 nucleotide RNA from poly (A)- RNA. We suggest that the 12S nuclear "termination" component is in fact a small nuclear RNP.
当将海胆粗疣海胆克隆的h22组蛋白基因重复单元注射到蛙卵母细胞核中时，转录在H3基因的启动子区域忠实地起始，但转录终止或RNA加工以产生真正的H3 mRNA 3'末端的效率非常低。在注射组蛋白基因重复单元前一天，将一小段海胆聚腺苷酸（poly (A)）-RNA注射到卵母细胞细胞质中，可以增强3'末端的产生。这种RNA长度约为60个核苷酸，在粗疣海胆和紫球海胆的胚胎中似乎含量相对较低。从核DEAE组分中提取的RNA，先前已证明可补充H3基因表达中的损伤，也会导致H3 mRNA真正3'末端的出现。此外，从我们的12S“终止”因子中提取的RNA包括一种与聚腺苷酸（poly (A)）-RNA中的60核苷酸RNA共迁移的RNA物种。我们认为12S核“终止”成分实际上是一种小核核糖核蛋白。
