Telomerase RNAs in land plants
Telomerase RNAs in land plants
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DOI：
10.1093/nar/gkz695
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发表时间：
2019-10-10
影响因子：
14.9
通讯作者：
Fajkus, Jiri
中科院分区：
文献类型：
--
作者：
Fajkus, Petr;Peska, Vratislav;Fajkus, Jiri
为了阐明芦笋目植物端粒进化变化的分子本质，我们旨在对这些植物的端粒酶RNA亚单位(TRs)进行特征分析。洋葱属植物中异常长的端粒重复单位(12个核苷酸)使我们能够在洋葱属代表性物种的转录数据中识别TRs。然后在含有TTAGGG(人型)或TTTAGGG(拟南芥类型)重复序列的端粒DNA的芦笋属植物中鉴定出同源的TRs。此外，我们确定了陆地植物系统发育中的TRs，包括常见的模式植物、农作物和具有不寻常端粒的植物。几条线的功能测试证明了已鉴定的Trs的模板端粒酶功能，并证明了之前在拟南芥中唯一报道的植物端粒酶RNA的功能。重要的是，我们的结果改变了植物端粒生物学中现有的范式，即基于相对保守的端粒酶逆转录酶亚基(TERT)的存在，即使在密切相关的植物分类群之间，端粒酶逆转录酶亚单位(TERT)也与高度不同的TRs相关。在陆地植物中发现真正的TRs的单系起源，为直接在转录或基因组数据中鉴定TRs和/或预测根据各自的TR模板区合成的端粒序列提供了可能性。
To elucidate the molecular nature of evolutionary changes of telomeres in the plant order Asparagales, we aimed to characterize telomerase RNA subunits (TRs) in these plants. The unusually long telomere repeat unit in Allium plants (12 nt) allowed us to identify TRs in transcriptomic data of representative species of the Allium genus. Orthologous TRs were then identified in Asparagales plants harbouring telomere DNA composed of TTAGGG (human type) or TTTAGGG (Arabidopsis-type) repeats. Further, we identified TRs across the land plant phylogeny, including common model plants, crop plants, and plants with unusual telomeres. Several lines of functional testing demonstrate the templating telomerase function of the identified TRs and disprove a functionality of the only previously reported plant telomerase RNA in Arabidopsis thaliana. Importantly, our results change the existing paradigm in plant telomere biology which has been based on the existence of a relatively conserved telomerase reverse transcriptase subunit (TERT) associating with highly divergent TRs even between closely related plant taxa. The finding of a monophyletic origin of genuine TRs across land plants opens the possibility to identify TRs directly in transcriptomic or genomic data and/or predict telomere sequences synthesized according to the respective TR template region.