Reconstitution of human shelterin complexes reveals unexpected stoichiometry and dual pathways to enhance telomerase processivity.
Reconstitution of human shelterin complexes reveals unexpected stoichiometry and dual pathways to enhance telomerase processivity.
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DOI：
10.1038/s41467-017-01313-w
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发表时间：
2017-10-20
影响因子：
16.6
通讯作者：
Cech TR
中科院分区：
文献类型：
--
作者：
Lim CJ;Zaug AJ;Kim HJ;Cech TR
人shelterin蛋白与端粒DNA结合，赋予端粒保护和长度调节。它们被认为形成了更高级的蛋白质复合物，但对shelterin蛋白的研究大多限于蛋白质对。在这里，我们共表达各种人类shelterin蛋白，并发现它们形成定义的多亚基复合物。含有TRF 2和POT 1的复合物对端粒DNA底物具有最强的结合亲和力，端粒DNA底物由具有3′单链延伸的双链DNA组成。在shelterin（RAP 12：TRF 22：TIN 21：TPP 11：POT 11）的情况下，TRF 2与TIN 2以出乎意料的2：1化学计量相互作用。TPP 1通过TRF 2-TIN 2或通过POT 1与端粒的连接提供了端粒酶持续合成能力的同等增强。我们还确定了一个肽区TPP 1，这是至关重要的和足够的TIN 2相互作用。我们的研究结果揭示了有关人类庇护所结构及其如何在端粒发挥功能的新信息。人类shelterin复合物保护端粒末端不被识别为受损的DNA位点，并与端粒酶一起调节端粒长度。在这里，作者建立了各种组成的人类shelterin复合物的化学计量学，并显示shelterin提供了刺激端粒酶合成能力的双重途径。
The human shelterin proteins associate with telomeric DNA to confer telomere protection and length regulation. They are thought to form higher-order protein complexes for their functions, but studies of shelterin proteins have been mostly limited to pairs of proteins. Here we co-express various human shelterin proteins and find that they form defined multi-subunit complexes. A complex harboring both TRF2 and POT1 has the strongest binding affinity to telomeric DNA substrates comprised of double-stranded DNA with a 3′ single-stranded extension. TRF2 interacts with TIN2 with an unexpected 2:1 stoichiometry in the context of shelterin (RAP12:TRF22:TIN21:TPP11:POT11). Tethering of TPP1 to the telomere either via TRF2–TIN2 or via POT1 gives equivalent enhancement of telomerase processivity. We also identify a peptide region from TPP1 that is both critical and sufficient for TIN2 interaction. Our findings reveal new information about the architecture of human shelterin and how it performs its functions at telomeres. The human shelterin complex protects telomere ends from being recognized as damaged DNA sites and regulates telomere length in conjunction with telomerase. Here the authors establish the stoichiometries of human shelterin complexes of various compositions and show shelterin provides dual pathways to stimulate telomerase processivity.
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影响因子：
14.9
作者：
Janoušková E;Nečasová I;Pavloušková J;Zimmermann M;Hluchý M;Marini V;Nováková M;Hofr C
通讯作者：
Hofr C
影响因子：
16
作者：
Chen, Liuh-Yow;Zhang, Yi;Zhang, Qinfen;Li, Hongzhi;Luo, Zhenhua;Fang, Hezhi;Kim, Sok Ho;Qin, Li;Yotnda, Patricia;Xu, Jianming;Tu, Benjamin P.;Bai, Yidong;Zhou Songyang
通讯作者：
Zhou Songyang
影响因子：
30.8
作者：
Broccoli, D;Smogorzewska, A;deLange, T
通讯作者：
deLange, T
影响因子：
16.8
作者：
Amiard, Simon;Doudeau, Michel;Giraud-Panis, Marie-Josephe
通讯作者：
Giraud-Panis, Marie-Josephe
影响因子：
9.8
作者：
Karlseder J;Hoke K;Mirzoeva OK;Bakkenist C;Kastan MB;Petrini JH;de Lange T
通讯作者：
de Lange T