Hori Tetsuya, Amano Miho, Suzuki Aussie, Backer Chelsea B, Welburn Julie P, Dong Yimin, McEwen Bruce F, Shang Wei-Hao, Suzuki Emiko, Okawa Katsuya, Cheeseman Iain M, Fukagawa Tatsuo
Department of Molecular Genetics, National Institute of Genetics and The Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka 411-8540, Japan.
Cell. 2008 Dec 12;135(6):1039-52. doi: 10.1016/j.cell.2008.10.019.
Kinetochore specification and assembly requires the targeted deposition of specialized nucleosomes containing the histone H3 variant CENP-A at centromeres. However, CENP-A is not sufficient to drive full-kinetochore assembly, and it is not clear how centromeric chromatin is established. Here, we identify CENP-W as a component of the DNA-proximal constitutive centromere-associated network (CCAN) of proteins. We demonstrate that CENP-W forms a DNA-binding complex together with the CCAN component CENP-T. This complex directly associates with nucleosomal DNA and with canonical histone H3, but not with CENP-A, in centromeric regions. CENP-T/CENP-W functions upstream of other CCAN components with the exception of CENP-C, an additional putative DNA-binding protein. Our analysis indicates that CENP-T/CENP-W and CENP-C provide distinct pathways to connect the centromere with outer kinetochore assembly. In total, our results suggest that the CENP-T/CENP-W complex is directly involved in establishment of centromere chromatin structure coordinately with CENP-A.
动粒的指定和组装需要在着丝粒处靶向沉积含有组蛋白H3变体CENP-A的特殊核小体。然而,CENP-A不足以驱动完整动粒的组装,并且尚不清楚着丝粒染色质是如何形成的。在这里,我们确定CENP-W是与着丝粒相关的蛋白质组成型网络(CCAN)中靠近DNA的一个组成部分。我们证明,CENP-W与CCAN组分CENP-T一起形成DNA结合复合物。在着丝粒区域,该复合物直接与核小体DNA和典型组蛋白H3结合,但不与CENP-A结合。除了CENP-C(另一种假定的DNA结合蛋白)外,CENP-T/CENP-W在其他CCAN组分的上游发挥作用。我们的分析表明,CENP-T/CENP-W和CENP-C提供了不同的途径来连接着丝粒与外动粒组装。总体而言,我们的结果表明,CENP-T/CENP-W复合物与CENP-A协同直接参与着丝粒染色质结构的形成。