Hefei National Laboratory for Physical Sciences at Microscale, the First Affiliated Hospital of USTC, CAS Center for Excellence in Biomacromolecules, and School of Life Sciences, University of Science and Technology of China, 96 Jinzhai Road, Hefei, 230026, Anhui, China.
Key Laboratory of Structural Biology, Chinese Academy of Sciences, Hefei, 230026, Anhui, China.
Cell Mol Life Sci. 2021 Jan;78(1):373-384. doi: 10.1007/s00018-020-03502-1. Epub 2020 Apr 21.
Faithful chromosome segregation during mitosis requires the correct assembly of kinetochore on the centromere. CENP-A is a variant of histone H3, which specializes the centromere region on chromatin and mediates the kinetochore assembly. The Mis18 complex plays a critical role in initiating the centromere loading of the newly-synthesized CENP-A. However, it remains unclear how Mis18 complex (spMis18, spMis16 and spMis19) is located to the centromere to license the recruitment of Cnp1 in Schizosaccharomyces pombe. We found that spMis18 directly binds to nucleosomal DNA through its extreme C-terminus and interacts with H2A-H2B dimer via the acidic region on the surface of its Yippee-like domain. Live-cell imaging confirmed that mutation of the acidic region and deletion of the extreme C-terminus significantly impairs the localization of spMis18 and Cnp1 to the centromere and delays chromosome segregation during mitosis. Our findings illustrate that the interaction of spMis18 with histone H2A-H2B and DNA plays important roles in the recruitment of spMis18 and Cnp1 to the centromere in fission yeast.
在有丝分裂过程中，染色体的正确分离需要动粒在着丝粒上的正确组装。CENP-A 是组蛋白 H3 的一种变体，它使染色质上的着丝粒区域特化，并介导动粒的组装。Mis18 复合物在启动新合成的 CENP-A 向着丝粒加载中起着关键作用。然而，Mis18 复合物（spMis18、spMis16 和 spMis19）如何定位到着丝粒以许可 Cnp1 在裂殖酵母中的招募仍不清楚。我们发现 spMis18 通过其极端 C 端直接与核小体 DNA 结合，并通过其 Yippee 样结构域表面的酸性区域与 H2A-H2B 二聚体相互作用。活细胞成像证实，酸性区域的突变和极端 C 端的缺失显著损害了 spMis18 和 Cnp1 向着丝粒的定位，并延迟了有丝分裂过程中的染色体分离。我们的研究结果表明，spMis18 与组蛋白 H2A-H2B 和 DNA 的相互作用在裂殖酵母中 spMis18 和 Cnp1 向着丝粒的招募中起着重要作用。
