Martin-Rivera L, Blasco M A
Department of Immunology and Oncology, Centro Nacional de Biotecnologia-CSIC, Campus Cantoblanco, E-28049 Madrid, Spain.
J Biol Chem. 2001 Feb 23;276(8):5856-65. doi: 10.1074/jbc.M008419200. Epub 2000 Oct 30.
The telomerase holoenzyme consists of two essential components, a reverse transcriptase, TERT (telomerase reverse transcriptase), and an RNA molecule, TR (telomerase RNA, also known as TERC), that contains the template for the synthesis of new telomeric repeats. Telomerase RNA has been isolated from 32 different vertebrates, and a common secondary structure has been proposed (Chen, J.-L., Blasco, M. A., and Greider, C. W. (2000) Cell 100, 503-514). We have generated 25 mutants in the four conserved structural domains of the mouse telomerase RNA molecule, mTR, and assayed their ability to reconstitute telomerase activity in mTR(-/-) cells in vivo. We found that the pseudoknot and the CR4/CR5 domains are required for telomerase activity but are not essential for mTR stability in the cell, whereas mutations in the BoxH/ACA and the CR7 domains affect mTR accumulation in the cell. We have also identified mTR mutants that are able to inhibit wild type telomerase in vivo.
端粒酶全酶由两个必需成分组成，一个逆转录酶，即端粒酶逆转录酶（TERT），以及一个RNA分子，即端粒酶RNA（也称为TERC），它包含合成新的端粒重复序列的模板。端粒酶RNA已从32种不同的脊椎动物中分离出来，并提出了一种共同的二级结构（Chen, J.-L., Blasco, M. A., and Greider, C. W. (2000) Cell 100, 503 - 514）。我们在小鼠端粒酶RNA分子mTR的四个保守结构域中产生了25个突变体，并检测了它们在体内重建mTR(-/-)细胞中端粒酶活性的能力。我们发现假结和CR4/CR5结构域是端粒酶活性所必需的，但对细胞中mTR的稳定性不是必需的，而BoxH/ACA和CR7结构域中的突变会影响mTR在细胞中的积累。我们还鉴定出了能够在体内抑制野生型端粒酶的mTR突变体。
