Mariasina Sofia S, Efimov Sergey V, Petrova Olga A, Rodina Elena V, Malyavko Alexander N, Zvereva Maria I, Klochkov Vladimir V, Dontsova Olga A, Polshakov Vladimir I
Center for Magnetic Tomography and Spectroscopy, Faculty of Fundamental Medicine, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991.
Department of Chemistry, M.V. Lomonosov Moscow State University, Moscow, Russia, 119991.
Biomol NMR Assign. 2018 Apr;12(1):57-62. doi: 10.1007/s12104-017-9780-5. Epub 2017 Sep 15.
Telomerase is a multisubunit ribonucleoprotein enzyme that is essential for continuous cellular proliferation. A key role of telomerase in cancer and ageing makes it a promising target for the development of cancer therapies and treatments of other age-associated diseases, since telomerase allows unlimited proliferation potential of cells in the majority of cancer types. However, the structure and molecular mechanism of telomerase action are still poorly understood. In budding yeast, telomerase consists of the catalytic subunit, the telomerase reverse transcriptase or Est2 protein, telomerase RNA (TLC1) and two regulatory subunits, Est1 and Est3. Each of the four subunits is essential for in vivo telomerase function. Est3 interacts directly with Est1 and Est2, and stimulates Est2 catalytic activity. However, the exact role of the Est3 protein in telomerase function is still unknown. Determination of the structure, dynamic and functional properties of Est3 can bring new insights into the molecular mechanism of telomerase activity. Here we report nearly complete H, C and N resonance assignments of Est3 from the yeast Hansenula polymorpha. Analysis of the assigned chemical shifts allowed us to identify the protein's secondary structure and backbone dynamic properties. Structure-based sequence alignment revealed similarities in the structural organization of yeast Est3 and mammalian TPP1 proteins.
端粒酶是一种多亚基核糖核蛋白酶，对细胞的持续增殖至关重要。端粒酶在癌症和衰老过程中发挥的关键作用使其成为开发癌症治疗方法及治疗其他与年龄相关疾病的一个有前景的靶点，因为在大多数癌症类型中，端粒酶赋予细胞无限增殖潜能。然而，端粒酶作用的结构和分子机制仍知之甚少。在芽殖酵母中，端粒酶由催化亚基、端粒酶逆转录酶或Est2蛋白、端粒酶RNA（TLC1）以及两个调节亚基Est1和Est3组成。这四个亚基中的每一个对于端粒酶在体内发挥功能都是必不可少的。Est3直接与Est1和Est2相互作用，并刺激Est2的催化活性。然而，Est3蛋白在端粒酶功能中的确切作用仍然未知。确定Est3的结构、动力学和功能特性能够为端粒酶活性的分子机制带来新的见解。在此，我们报告了来自多形汉逊酵母的Est3的几乎完整的氢、碳和氮共振归属。对已归属化学位移的分析使我们能够确定该蛋白的二级结构和主链动力学特性。基于结构的序列比对揭示了酵母Est3和哺乳动物TPP1蛋白在结构组织上的相似性。
