Pennock E, Buckley K, Lundblad V
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
Cell. 2001 Feb 9;104(3):387-96. doi: 10.1016/s0092-8674(01)00226-4.
In Saccharomyces cerevisiae, the telomere binding protein Cdc13 mediates telomere replication by recruiting telomerase, and also performs an essential function in chromosome end protection. We show here that delivery of the Stn1 protein to the telomere, by fusing the DNA binding domain of Cdc13 (DBD(CDC13)) to Stn1, is sufficient to rescue the lethality of a cdc13 null strain and, hence, provide end protection. Telomere replication is still defective in this strain, but can be restored by delivering telomerase to the telomere as a DBD(CDC13)-telomerase fusion. These results establish Stn1 as the primary effector of chromosome end protection, whereas the principal function of Cdc13 is to provide a loading platform to recruit complexes that provide end protection and telomere replication.
在酿酒酵母中，端粒结合蛋白Cdc13通过招募端粒酶介导端粒复制，并且在染色体末端保护中发挥重要作用。我们在此表明，通过将Cdc13的DNA结合结构域（DBD(CDC13)）与Stn1融合，将Stn1蛋白递送至端粒，足以挽救cdc13缺失菌株的致死性，从而提供末端保护。该菌株中的端粒复制仍然存在缺陷，但可以通过将端粒酶作为DBD(CDC13)-端粒酶融合体递送至端粒来恢复。这些结果确定Stn1为染色体末端保护的主要效应因子，而Cdc13的主要功能是提供一个加载平台，以招募提供末端保护和端粒复制的复合物。
