Wellinger R J, Ethier K, Labrecque P, Zakian V A
Department of Microbiology, Faculty of Medicine, Université de Sherbrooke, Quebec, Canada.
Cell. 1996 May 3;85(3):423-33. doi: 10.1016/s0092-8674(00)81120-4.
The strand of telomeric DNA that runs 5'-3' toward a chromosome end is typically G rich. Telomerase-generated G tails are expected at one end of individual DNA molecules. Saccharomyces telomeres acquire TG1-3 tails late in S phase. Moreover, the telomeres of linear plasmids can interact when the TG1-3 tails are present. Molecules that mimic the structures predicted for telomere replication intermediates were generated in vitro. These in vitro generated molecules formed telomere-telomere interactions similar to those on molecules isolated from yeast, but only if both ends that interacted had a TG1-3 tail. Moreover, TG1-3 tails were generated in vivo in cells lacking telomerase. These data suggest a new step in telomere maintenance, cell cycle-regulated degradation of the C1-3A strand, which can generate a potential substrate for telomerase and telomere-binding proteins at every telomere.
朝向染色体末端按5'-3'方向延伸的端粒DNA链通常富含鸟嘌呤（G）。在单个DNA分子的一端预期会出现端粒酶生成的G尾。酿酒酵母的端粒在S期后期获得TG1-3尾。此外，当存在TG1-3尾时，线性质粒的端粒可以相互作用。在体外生成了模拟端粒复制中间体预测结构的分子。这些体外生成的分子形成了与从酵母中分离出的分子相似的端粒-端粒相互作用，但前提是相互作用的两端都有TG1-3尾。此外，在缺乏端粒酶的细胞中，体内也会生成TG1-3尾。这些数据表明端粒维持过程中有一个新步骤，即C1-3A链的细胞周期调控降解，这可以在每个端粒处为端粒酶和端粒结合蛋白生成潜在底物。
