线虫非编码基因上游motif的初步分析

Analysis of Motif in the Upstream Region of ncRNAs Genes in C.elegans

非编码基因是能产生有功能的RNA而不编码蛋白质的一类特殊序列。通过Northern印迹杂交(Northern blot)方法在线虫体内鉴定了100个非编码RNA,并且预测了这些小RNA上游保守的特征序列,这些序列位于转录的初始区域,很可能与某些蛋白结合调控转录的起始。采用EMSA(Electrophoretic Mobility Shift Assay)凝胶迁移实验方法分析了其中的两类特征序列UM1和UM3,结果表明UM1和UM3都分别能结合蛋白复合物UM1P和UM2P;通过特异性的竞争反应表明,UM3可以竞争UM1的结合部位,使得UM1不能与UM1P结合,相反UM1却不能影响UM3与UM3P的结合。上述结果暗示了UM1与UM3有相似的序列位点A,UM1P可能只识别A位点,而UM3P除了识别A位点还识别UM3其他的位点。这与预测结果是一致的,UM1与UM3有相似的位点TGTCTG。这些特征序列与蛋白复合物结合的特异性暗示了它们可能是启动子区域与转录因子,该分析结果为研究线虫非编码RNA的转录调控提供了一定的依据。

Noncoding RNAs （ncRNAs） are genes that produce the functional RNA instead of encoding proteins. Our lab also has recently detected a number of novel ncRNAs in C. elegans and many conserved upstream motifs that may have promoter active and interact with some transcription factors. We cloned two ncRNAs upstream motifs （UM） and analyzed the interaction between motifs and protein by EMSA. The results showed that UM1 and UM2 respectively to integrate protein complexes UM1P and UM2P, through specific competition reaction showed that The UM1 was competed out when the reaction was carried out by excess of the unlabeled UM3, but the retarded band of UM3 was not affected when unlabeled UM1 was used as a competitor in the reaction buffer. These results imply that the motifs of UMland UM3 have similar loci A, the UM1P could only identify the loci A, and the addition to UM3P recognition A site also identify other sites of UM3. This situation is exactly with our forecast： UM1 and UM3 have similar sites TGTCTG. These DNA-protein complex combinations of specific suggested that they may the promoter region and the transcription factor. The analysis results for the study of non-coding RNA nematodes in the transcriptional regulation of certain basis.