School of Life Sciences, Queens Medical Centre, University of Nottingham, Nottingham NG7 2UH, UK.
Department of Molecular, Cell and Systems Biology, University of California Riverside, 900 University Ave., Riverside, CA 92521, USA.
Cell Rep. 2020 Feb 11;30(6):1883-1897.e6. doi: 10.1016/j.celrep.2020.01.033.
Condensin is a multi-subunit protein complex regulating chromosome condensation and segregation during cell division. In Plasmodium spp., the causative agent of malaria, cell division is atypical and the role of condensin is unclear. Here we examine the role of SMC2 and SMC4, the core subunits of condensin, during endomitosis in schizogony and endoreduplication in male gametogenesis. During early schizogony, SMC2/SMC4 localize to a distinct focus, identified as the centromeres by NDC80 fluorescence and chromatin immunoprecipitation sequencing (ChIP-seq) analyses, but do not form condensin I or II complexes. In mature schizonts and during male gametogenesis, there is a diffuse SMC2/SMC4 distribution on chromosomes and in the nucleus, and both condensin I and condensin II complexes form at these stages. Knockdown of smc2 and smc4 gene expression reveals essential roles in parasite proliferation and transmission. The condensin core subunits (SMC2/SMC4) form different complexes and may have distinct functions at various stages of the parasite life cycle.
凝缩蛋白是一种多亚基蛋白复合物，在细胞分裂过程中调节染色体的凝聚和分离。在疟原虫等引起疟疾的病原体中，细胞分裂是非典型的，凝缩蛋白的作用尚不清楚。在这里，我们研究了 SMC2 和 SMC4（凝缩蛋白的核心亚基）在裂殖和雄性配子发生中的内复制过程中的核内有丝分裂中的作用。在早期裂殖过程中，SMC2/SMC4 定位于一个独特的焦点，通过 NDC80 荧光和染色质免疫沉淀测序 (ChIP-seq) 分析鉴定为着丝粒，但不会形成凝缩蛋白 I 或 II 复合物。在成熟的裂殖体和雄性配子发生过程中，SMC2/SMC4 在染色体和核内呈弥散分布，并且在这些阶段形成凝缩蛋白 I 和凝缩蛋白 II 复合物。smc2 和 smc4 基因表达的敲低揭示了它们在寄生虫增殖和传播中的重要作用。凝缩蛋白核心亚基（SMC2/SMC4）形成不同的复合物，在寄生虫生命周期的不同阶段可能具有不同的功能。
