ABSTRACT Plants possess the structural maintenance of chromosome (SMC) protein complexes cohesin, condensin, and SMC5/6, which function in fundamental biological processes such as sister chromatid cohesion, chromosome condensation and segregation, and damaged DNA repair. Recently, increasing evidence in several organisms has suggested that condensin is involved in chromatin organizations during interphase. In Arabidopsis thaliana, condensin II is localized in the nucleus throughout interphase and is suggested to be required for keeping centromeres apart and the assembly of euchromatic chromosome arms. However, it remains unclear how condensin II organizes chromatin associations. Here, we first showed the high possibility that the function of condensin II as a complex is required for the disassociation of centromeres. Analysis of the rDNA array distribution revealed that condensin II is also indispensable for the association of centromeres with rDNA arrays. Reduced axial compaction of chromosomes and impaired genome integrity in condensin II mutants are not related to the disruption of chromatin organization. In contrast, the axial compaction of chromosomes by condensin II produces the force leading to the disassociation of heterologous centromeres in Drosophila melanogaster. Taken together, our data imply that the condensin II function in chromatin organization differs among eukaryotes.

中文翻译：

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着丝粒和 rDNA 阵列之间正确的空间关系需要植物凝聚素 II

摘要 植物具有染色体 (SMC) 蛋白复合物 cohesin、condensin 和 SMC5/6 的结构维持，它们在基本生物过程中起作用，例如姐妹染色单体凝聚、染色体凝聚和分离以及受损的 DNA 修复。最近，在一些生物体中越来越多的证据表明凝聚素在间期参与染色质组织。在拟南芥中，凝聚素 II 位于整个间期的细胞核中，被认为是保持着丝粒分开和组装常染色体臂所必需的。然而，目前尚不清楚凝聚素 II 如何组织染色质关联。在这里，我们首先表明，着丝粒解离需要凝聚素 II 作为复合物的功能的可能性很高。rDNA 阵列分布的分析表明，凝聚素 II 对于着丝粒与 rDNA 阵列的关联也是必不可少的。凝聚素 II 突变体中染色体轴向压缩减少和基因组完整性受损与染色质组织的破坏无关。相比之下，凝聚素 II 对染色体的轴向压缩产生了导致黑腹果蝇中异源着丝粒分离的力。总之，我们的数据意味着染色质组织中的凝聚素 II 功能在真核生物中有所不同。凝聚素 II 对染色体的轴向压缩产生了导致黑腹果蝇中异源着丝粒解离的力。总之，我们的数据意味着染色质组织中的凝聚素 II 功能在真核生物中有所不同。凝聚素 II 对染色体的轴向压缩产生了导致黑腹果蝇中异源着丝粒分离的力。总之，我们的数据意味着染色质组织中的凝聚素 II 功能在真核生物中有所不同。