Fini M E, Bendena W G, Pardue M L
Department of Biology, Massachusetts Institute of Technology, Cambridge 02139.
J Cell Biol. 1989 Jun;108(6):2045-57. doi: 10.1083/jcb.108.6.2045.
Although a major site of transcription in heat shock, the Drosophila hsr omega gene does not encode any known heat shock proteins. Instead, studies of the hsr omega transcripts suggest that the RNA molecules, rather than encoded proteins, are the active products of this gene. The cytoplasmic RNA, omega 3, is spliced and polyadenylated and yet has only very small open reading frames (ORFs), and these are poorly conserved in different Drosophila species. Surprisingly, the work reported here leads us to conclude that one of the tiny ORFs in this RNA is translated. This ORF, designated ORF-omega, is notable in being the only ORF that shows sequence conservation in the three Drosophila species examined. However, translation of this ORF does not lead to detectable accumulation of the protein product. We suggest that ORF-omega may be an example of an unusual type of translated ORF. The act of translation itself may be important rather than the generation of a functional protein product. This nonproductive translation may play a role in regulation of cellular activities.
尽管果蝇热休克蛋白omega基因（hsr omega）是热休克中转录的主要位点，但它并不编码任何已知的热休克蛋白。相反，对hsr omega转录本的研究表明，RNA分子而非编码的蛋白质是该基因的活性产物。细胞质RNA，即omega 3，经过剪接和聚腺苷酸化，但其开放阅读框（ORF）非常小，并且在不同的果蝇物种中保守性很差。令人惊讶的是，本文报道的研究使我们得出结论，该RNA中的一个小ORF被翻译了。这个ORF被命名为ORF-omega，值得注意的是，它是在所研究的三种果蝇物种中唯一显示出序列保守性的ORF。然而，该ORF的翻译并未导致可检测到的蛋白质产物积累。我们认为ORF-omega可能是一种不寻常的翻译ORF的例子。翻译行为本身可能很重要，而不是产生功能性蛋白质产物。这种无生产性的翻译可能在细胞活动的调节中起作用。
