由RNA调控的一些类型的沉默过程涉及次级siRNA的生成，它们是通过将单链RNA转变成双链RNA生成的。这个过程是由一个“依赖于RNA的RNA聚合酶”（ RdRP）完成的。
现在，Maida等人发现，TERT（端粒酶的催化亚单元）可从线粒体“RNA处理核糖核酸内切酶”（RMRP）的RNA部分生成dsRNA——以前的研究表明，线粒体RMRP在“软骨毛发发育不全”（一种遗传性矮小症）中发生突变。所生成的dsRNA可被核糖核酸内切酶“切片机”处理成siRNA。这是关于一种哺乳动物RdRP活性的首次报告。越来越多的证据表明，TERT对细胞生理有所帮助，这种作用独立于其使端粒伸长的能力，而这项新的研究工作则指出了其中所涉及的机制之一。(生物谷Bioon.com)
生物谷推荐原始出处：
Nature 461, 230-235 (10 September 2009) | doi:10.1038/nature08283
An RNA-dependent RNA polymerase formed by TERT and the RMRP RNA
Yoshiko Maida1, Mami Yasukawa1, Miho Furuuchi1, Timo Lassmann2, Richard Possemato3, Naoko Okamoto1, Vivi Kasim1, Yoshihide Hayashizaki2, William C. Hahn3,4 & Kenkichi Masutomi1,5
1 Cancer Stem Cell Project, National Cancer Center Research Institute, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan
2 RIKEN Omics Science Center, RIKEN Yokohama Institute, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
3 Department of Medical Oncology, Dana-Farber Cancer Institute and Departments of Medicine, Brigham and Women's Hospital and Harvard Medical School, 44 Binney Street, Boston, Massachusetts 02115, USA
4 Broad Institute of Harvard and MIT, 7 Cambridge Center, Cambridge, Massachusetts 02142, USA
5 PREST, Japan Science and Technology Agency, 4-1-8 Honcho Kawaguchi, Saitama 332-0012, Japan
Correspondence to: William C. Hahn3,4Kenkichi Masutomi1,5 Correspondence and requests for materials should be addressed to W.C.H. or K.M.
Constitutive expression of telomerase in human cells prevents the onset of senescence and crisis by maintaining telomere homeostasis. However, accumulating evidence suggests that the human telomerase reverse transcriptase catalytic subunit (TERT) contributes to cell physiology independently of its ability to elongate telomeres. Here we show that TERT interacts with the RNA component of mitochondrial RNA processing endoribonuclease (RMRP), a gene that is mutated in the inherited pleiotropic syndrome cartilage–hair hypoplasia. Human TERT and RMRP form a distinct ribonucleoprotein complex that has RNA-dependent RNA polymerase (RdRP) activity and produces double-stranded RNAs that can be processed into small interfering RNA in a Dicer (also known as DICER1)-dependent manner. These observations identify a mammalian RdRP composed of TERT in complex with RMRP.
