The S. pombe telomerase RNA: secondary structure and flexible scaffold function

[摘要] Telomerase RNAs are rapidly evolving long non-coding RNAs that perform a conserved function along with telomerase protein subunits: maintaining chromosome ends. While the telomerase enzyme is not expressed in the majority of human somatic cells, it is found in the vast majority of cancer cells.Little is known about the structure of the 1212-nt telomerase RNA, TER1, from the fission yeast Schizosaccharomyces pombe, which has similar telomere biology to humans. Here, we provide the first working model for TER1 based on phylogenetics and bioinformatic modeling. We also identify a new essential element within TER1, the T1 region, by testing truncation mutants in vivo, as well as discover that several large regions of the RNA are dispensable for function in vivo, consistent with flexible-scaffold function. We show that TER1 functions as a flexible scaffold for the essential three-way-junction element by showing that this element functions despite being relocated to two different positions on the RNA. Furthermore, we show that a half-sized fission yeast telomerase RNA is able to extend telomeres in vitro. Overall, our findings demonstrate that the flexible scaffolding role of telomerase RNA is conserved between distant fungal species.

[发布机构] Johns Hopkins University

[效力级别] pombe

[关键词] Telomerase;pombe;Biology