School of Life Sciences, University of Nottingham, Nottingham, UK
Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK.
Life Sci Alliance. 2022 May 12;5(9). doi: 10.26508/lsa.202101329. Print 2022 Sep.
The centriole/basal body (CBB) is an evolutionarily conserved organelle acting as a microtubule organising centre (MTOC) to nucleate cilia, flagella, and the centrosome. SAS4/CPAP is a conserved component associated with BB biogenesis in many model flagellated cells. , a divergent unicellular eukaryote and causative agent of malaria, displays an atypical, closed mitosis with an MTOC (or centriolar plaque), reminiscent of an acentriolar MTOC, embedded in the nuclear membrane. Mitosis during male gamete formation is accompanied by flagella formation. There are two MTOCs in male gametocytes: the acentriolar nuclear envelope MTOC for the mitotic spindle and an outer centriolar MTOC (the basal body) that organises flagella assembly in the cytoplasm. We show the coordinated location, association and assembly of SAS4 with the BB component, kinesin-8B, but no association with the kinetochore protein, NDC80, indicating that SAS4 is part of the BB and outer centriolar MTOC in the cytoplasm. Deletion of the gene produced no phenotype, indicating that it is not essential for either male gamete formation or parasite transmission.
中心体/基体（CBB）是一种进化上保守的细胞器，作为微管组织中心（MTOC），可以引发纤毛、鞭毛和中心体。SAS4/CPAP 是与许多模型鞭毛细胞的 BB 发生相关的保守成分。一种有分歧的单细胞真核生物和疟疾的病原体，表现出一种非典型的封闭有丝分裂，其中有一个 MTOC（或中心粒斑），类似于无中心粒的 MTOC，嵌入核膜中。在雄性配子形成过程中伴随着鞭毛的形成。雄性配子中有两个 MTOC：用于有丝分裂纺锤体的无中心粒核膜 MTOC 和位于细胞质中组织鞭毛组装的外中心粒 MTOC（基体）。我们展示了 SAS4 与 BB 成分、驱动蛋白-8B 的协调定位、关联和组装，但与动粒蛋白 NDC80 没有关联，这表明 SAS4 是 BB 和细胞质中外中心粒 MTOC 的一部分。基因的缺失没有产生表型，表明它对于雄性配子的形成或寄生虫的传播都不是必需的。
