Wellcome Centre for Integrative Parasitology, Institute of Infection, Immunity & Inflammation, University of Glasgow, Glasgow, United Kingdom.
Faculty of Veterinary Medicine, Experimental Parasitology, Ludwig Maximilian University, Munich, Germany.
Elife. 2019 Jul 19;8:e49030. doi: 10.7554/eLife.49030.
In addition to its role in erythrocyte invasion, actin is implicated in endocytosis, cytokinesis and inheritance of the chloroplast-like organelle called the apicoplast. Previously, the inability to visualise filamentous actin (F-actin) dynamics had restricted the characterisation of both F-actin and actin regulatory proteins, a limitation we recently overcame for (Periz et al, 2017). Here, we have expressed and validated actin-binding chromobodies as F-actin-sensors in and characterised actin dynamics. F-actin could be chemically modulated, and genetically disrupted upon conditionally deleting . In a comparative approach, we demonstrate that Formin-2, a predicted nucleator of F-actin, is responsible for apicoplast inheritance in both and , and additionally mediates efficient cytokinesis in . Finally, time-averaged local intensity measurements of F-actin in conditional mutants revealed molecular determinants of spatiotemporally regulated F-actin flow. Together, our data indicate that Formin-2 is the primary F-actin nucleator during apicomplexan intracellular growth, mediating multiple essential functions.
除了在红细胞入侵中的作用外，肌动蛋白还与内吞作用、胞质分裂和叶绿体样细胞器（称为顶质体）的遗传有关。以前，由于无法可视化丝状肌动蛋白（F-actin）的动力学，限制了对 F-actin 和肌动蛋白调节蛋白的特征描述，我们最近克服了这一限制（Periz 等人，2017 年）。在这里，我们已经在 和 中表达和验证了肌动蛋白结合结构域作为 F-actin 的传感器，并对 actin 动力学进行了表征。F-actin 可以通过化学方法进行调节，并在条件性删除 时发生遗传破坏。在一种比较方法中，我们证明了 Formin-2，一种预测的 F-actin 成核因子，负责 和 中的顶质体遗传，并且还介导了 在 中的有效胞质分裂。最后，对 条件突变体中 F-actin 的时间平均局部强度测量揭示了时空调节 F-actin 流的分子决定因素。总之，我们的数据表明，Formin-2 是顶复寄生虫细胞内生长过程中主要的 F-actin 成核因子，介导多种必需功能。
