Structural Maintenance of Chromosomes 2 (SMC2) and Structural Maintenance of Chromosomes 4 (SMC4) are the core components of the condensin complexes, which are required for chromosome assembly and faithful segregation during cell division. Because of the crucial functions of both proteins in cell division, much work has been done in various vertebrates, but little information is known about their roles in plants. Here, we identified ZmSMC2 and ZmSMC4 in maize (Zea mays) and confirmed that ZmSMC2 associates with ZmSMC4 via their hinge domains. Immunostaining revealed that both proteins showed dynamic localization during mitosis. ZmSMC2 and ZmSMC4 are essential for proper chromosome segregation and for H3 phosphorylation at Serine 10 (H3S10ph) at pericentromeres during mitotic division. The loss of function of ZmSMC2 and ZmSMC4 enlarges mitotic chromosome volume and impairs sister chromatid separation to the opposite poles. Taken together, these findings confirm and extend the coordinated role of ZmSMC2 and ZmSMC4 in maintenance of normal chromosome architecture and accurate segregation during mitosis.

中文翻译：

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凝集素亚基SMC2和SMC4相互作用，以使有丝分裂玉米染色体正确凝缩和分离。

染色体2（SMC2）的结构维护和染色体4（SMC4）的结构维护是condensin复合体的核心组成部分，它们是染色体组装和细胞分裂过程中忠实分离所必需的。由于这两种蛋白在细胞分裂中起着至关重要的作用，因此在各种脊椎动物中已经做了很多工作，但是关于它们在植物中的作用的信息很少。在这里，我们在玉米（Zea mays）中鉴定了ZmSMC2和ZmSMC4，并确认ZmSMC2通过其铰链结构域与ZmSMC4缔合。免疫染色显示这两种蛋白质在有丝分裂过程中均显示动态定位。ZmSMC2和ZmSMC4对于正确的染色体分离和有丝分裂分裂过程中着丝点的丝氨酸10（H3S10ph）处的H3磷酸化至关重要。ZmSMC2和ZmSMC4的功能丧失会扩大有丝分裂染色体的体积，并损害姐妹染色单体向相反两极的分离。综上所述，这些发现证实并扩展了ZmSMC2和ZmSMC4在维持正常染色体结构和有丝分裂期间精确隔离中的协调作用。