酵母snoRNA基因簇启动子的比较分析

Comparative Analysis of Yeast snoRNA Gene Cluster Promoter

报道对酿酒酵母ｓｎｏＲＮＡ基因簇启动子序列的研究结果．通过计算机分析，发现酿酒酵母中Ｚ２Ｚ８和ＳｎＲ１９０Ｕ１４ｓｎｏＲＮＡ基因簇有相似的启动子结构．这两个ｓｎｏＲＮＡ基因簇都是由一个上游的启动子负责整个基因簇的转录，产生多个顺反子ｓｎｏＲＮＡ的前体，然后再加工成熟为各个独立的ｓｎｏＲＮＡ．在启动子保守序列ＴＡＴＡｂｏｘ的上游还发现２个ＲＡＰ１序列，表明ｓｎｏＲＮＡ基因簇的表达可以通过ＲＡＰ１元素与核糖体蛋白基因的表达协同调控．这是在ｓｎｏＲＮＡ基因的启动子中首次发现ＲＡＰ１调控元素．对ｓｎｏＲＮＡ基因簇的进化特点也进行了讨论．

Saccharomyces cerevisiae snoRNA gene organization has shown some distinguished features from its homologue in vertebrates By computer analysis, we have characterized the promoter elements of the Z2 Z8 snoRNA gene cluster Only one upstream promoter was found to be responsible for the transcription of all snoRNA genes in the cluster, resulting in a polycistronic RNA precursor followed by processing to produce each individual snoRNA The same is true for another snoRNA gene cluster containing snR190 and U14 More interestingly, two RAP1 sequences, located upstream from the TATA box of the promoter were identified for both of the two snoRNA clusters, indicating a close coordination of transcriptional regulation between the snoRNA gene cluster and ribosomal protein gene in the course of ribosome biogenesis This is the first report for the RAP1 element in snoRNA gene The evolutionary significance of snoRNA gene cluster was also discussed