Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) Gatersleben, Corrensstrasse 3, D-06466, Seeland, Germany.
Department of Biotechnology Engineering, Braude Academic College of Engineering, Snunit 51, Karmiel, 2161002, Israel.
Plant J. 2024 May;118(4):982-996. doi: 10.1111/tpj.16445. Epub 2023 Sep 4.
Centromeres are the chromosomal domains, where the kinetochore protein complex is formed, mediating proper segregation of chromosomes during cell division. Although the function of centromeres has remained conserved during evolution, centromeric DNA is highly variable, even in closely related species. In addition, the composition of the kinetochore complexes varies among organisms. Therefore, it is assumed that the centromeric position is determined epigenetically, and the centromeric histone H3 (CENH3) serves as an epigenetic marker. The loading of CENH3 onto centromeres depends on centromere-licensing factors, chaperones, and transcription of centromeric repeats. Several proteins that regulate CENH3 loading and kinetochore assembly interact with the centromeric transcripts and DNA in a sequence-independent manner. However, the functional aspects of these interactions are not fully understood. This review discusses the variability of centromeric sequences in different organisms and the regulation of their transcription through the RNA Pol II and RNAi machinery. The data suggest that the interaction of proteins involved in CENH3 loading and kinetochore assembly with centromeric DNA and transcripts plays a role in centromere, and possibly neocentromere, formation in a sequence-independent manner.
着丝粒是染色体的结构域，在这里形成动粒蛋白复合物，介导细胞分裂过程中染色体的正确分离。尽管着丝粒的功能在进化过程中保持保守，但着丝粒 DNA 高度可变，即使在密切相关的物种中也是如此。此外，动粒复合物的组成在不同的生物体中也有所不同。因此，人们假设着丝粒的位置是通过表观遗传决定的，着丝粒组蛋白 H3（CENH3）作为一种表观遗传标记。CENH3 加载到着丝粒上取决于着丝粒许可因子、伴侣蛋白和着丝粒重复序列的转录。几种调节 CENH3 加载和动粒组装的蛋白质与着丝粒转录本和 DNA 以序列非依赖性方式相互作用。然而，这些相互作用的功能方面尚未完全了解。这篇综述讨论了不同生物体中着丝粒序列的可变性以及通过 RNA Pol II 和 RNAi 机制对其转录的调节。这些数据表明，参与 CENH3 加载和动粒组装的蛋白质与着丝粒 DNA 和转录本的相互作用在序列非依赖性方式中在着丝粒（可能是新着丝粒）形成中发挥作用。
