A cooperative mechanism drives budding yeast kinetochore assembly downstream of CENP-A.
A cooperative mechanism drives budding yeast kinetochore assembly downstream of CENP-A.
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DOI：
10.1083/jcb.201403081
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发表时间：
2014-08-18
期刊：
影响因子：
--
通讯作者：
Westermann S
中科院分区：
文献类型：
--
作者：
Hornung P;Troc P;Malvezzi F;Maier M;Demianova Z;Zimniak T;Litos G;Lampert F;Schleiffer A;Brunner M;Mechtler K;Herzog F;Marlovits TC;Westermann S
在芽殖酵母中的动粒组装期间，CENP-A识别和外部动粒募集的关键步骤通过不同的酵母CCAN亚基执行，从而潜在地防止不适当的动粒组装。着丝粒是真核生物中介导染色体-微管相互作用的兆道尔顿大小的蛋白质复合物。着丝粒染色质上的动粒组装是如何被触发的还不清楚。在这里，我们使用生化重建实验，遗传和结构分析，描绘着丝粒相关蛋白质的贡献，在酵母动粒组装。我们发现，保守的动粒亚基Ame 1CENP-U和Okp 1CENP-Q形成一个DNA结合复合物，该复合物通过Ame 1 N末端的短Mtw 1募集基序与微管结合KMN网络相关联。Ame 1基序中的点突变通过阻止KMN在染色质上的组装来破坏动粒功能。Ame 1-Okp 1与着丝粒蛋白C（CENP-C）同源物Mif 2直接结合，形成外动粒组装的协同结合平台。我们的研究结果表明，关键的组装步骤，CENP-A的识别和外动粒招聘，通过不同的酵母组成型着丝粒相关的网络亚基执行。这种两步机制可以防止不适当的动粒组装类似于细胞骨架聚合物所使用的限速成核步骤。
During kinetochore assembly in budding yeast, the key steps of CENP-A recognition and outer kinetochore recruitment are executed through different yeast CCAN subunits, potentially protecting against inappropriate kinetochore assembly. Kinetochores are megadalton-sized protein complexes that mediate chromosome–microtubule interactions in eukaryotes. How kinetochore assembly is triggered specifically on centromeric chromatin is poorly understood. Here we use biochemical reconstitution experiments alongside genetic and structural analysis to delineate the contributions of centromere-associated proteins to kinetochore assembly in yeast. We show that the conserved kinetochore subunits Ame1CENP-U and Okp1CENP-Q form a DNA-binding complex that associates with the microtubule-binding KMN network via a short Mtw1 recruitment motif in the N terminus of Ame1. Point mutations in the Ame1 motif disrupt kinetochore function by preventing KMN assembly on chromatin. Ame1–Okp1 directly associates with the centromere protein C (CENP-C) homologue Mif2 to form a cooperative binding platform for outer kinetochore assembly. Our results indicate that the key assembly steps, CENP-A recognition and outer kinetochore recruitment, are executed through different yeast constitutive centromere-associated network subunits. This two-step mechanism may protect against inappropriate kinetochore assembly similar to rate-limiting nucleation steps used by cytoskeletal polymers.
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影响因子：
16
作者：
Hewawasam G;Shivaraju M;Mattingly M;Venkatesh S;Martin-Brown S;Florens L;Workman JL;Gerton JL
通讯作者：
Gerton JL
影响因子：
48
作者：
Kastner, Berthold;Fischer, Niels;Stark, Holger
通讯作者：
Stark, Holger
DOI：
10.1083/jcb.201001013
发表时间：
2010-06-28
期刊：
The Journal of cell biology
影响因子：
--
作者：
Carroll CW;Milks KJ;Straight AF
通讯作者：
Straight AF
影响因子：
3.3
作者：
Cohen, R. L.;Espelin, C. W.;Simons, K. T.
通讯作者：
Simons, K. T.
影响因子：
64.5
作者：
Ciferri, Claudio;Pasqualato, Sebastiano;Musacchio, Andrea
通讯作者：
Musacchio, Andrea