Chan Simon R W L, Blackburn Elizabeth H
University of California, San Francisco, Biochemistry and Biophysics, Box 2200, San Francisco, CA 94143-2200, USA.
Philos Trans R Soc Lond B Biol Sci. 2004 Jan 29;359(1441):109-21. doi: 10.1098/rstb.2003.1370.
Telomeres are the protective DNA-protein complexes found at the ends of eukaryotic chromosomes. Telomeric DNA consists of tandem repeats of a simple, often G-rich, sequence specified by the action of telomerase, and complete replication of telomeric DNA requires telomerase. Telomerase is a specialized cellular ribonucleoprotein reverse transcriptase. By copying a short template sequence within its intrinsic RNA moiety, telomerase synthesizes the telomeric DNA strand running 5' to 3' towards the distal end of the chromosome, thus extending it. Fusion of a telomere, either with another telomere or with a broken DNA end, generally constitutes a catastrophic event for genomic stability. Telomerase acts to prevent such fusions. The molecular consequences of telomere failure, and the molecular contributors to telomere function, with an emphasis on telomerase, are discussed here.
端粒是真核染色体末端的保护性DNA - 蛋白质复合物。端粒DNA由端粒酶作用产生的简单串联重复序列组成，通常富含鸟嘌呤，端粒DNA的完全复制需要端粒酶。端粒酶是一种特殊的细胞核糖核蛋白逆转录酶。通过复制其内在RNA部分中的短模板序列，端粒酶合成向染色体远端5'至3'延伸的端粒DNA链，从而延长染色体。端粒与另一个端粒或与断裂的DNA末端融合，通常对基因组稳定性构成灾难性事件。端粒酶起到防止这种融合的作用。本文讨论了端粒功能障碍的分子后果以及端粒功能的分子影响因素，重点是端粒酶。
