Department of Microbiology and Molecular Medicine, CMU, University of Geneva, Geneva, Switzerland.
Department of Biochemistry, University of Cambridge, Cambridge CB2 1QW, UK.
Trends Parasitol. 2020 Aug;36(8):688-704. doi: 10.1016/j.pt.2020.05.001. Epub 2020 May 31.
The phylum Apicomplexa has been defined by the presence of the apical complex, a structure composed of secretory organelles and specific cytoskeletal elements. A conspicuous feature of the apical complex in many apicomplexans is the conoid, a hollow tapered barrel structure composed of tubulin fibers. In Toxoplasma gondii, the apical complex is a central site of convergence for calcium-related and lipid-mediated signaling pathways that coordinate conoid protrusion, microneme secretion, and actin polymerization, to initiate gliding motility. Through cutting-edge technologies, great progress has recently been made in discovering the structural subcomponents and proteins implicated in the biogenesis and stability of the apical complex and, in turn, these discoveries have shed new light on the function and evolution of this definitive structure.
肉足鞭毛门已被定义为具有顶复合结构，这是一种由分泌细胞器和特定细胞骨架元素组成的结构。在许多肉足鞭毛虫中，顶复合结构的一个显著特征是锥体，这是一个由微管蛋白纤维组成的中空锥形桶状结构。在刚地弓形虫中，顶复合结构是钙相关和脂类介导的信号通路的中心汇聚点，这些信号通路协调锥体的突出、微线体的分泌和肌动蛋白的聚合，以启动滑行运动。通过尖端技术，最近在发现与顶复合结构的生物发生和稳定性相关的结构亚成分和蛋白质方面取得了巨大进展，这些发现反过来又为这个明确结构的功能和进化提供了新的线索。
