Department of Biology, Indiana University, Bloomington, IN 47405, USA.
Department of Biology, Indiana University, Bloomington, IN 47405, USA
J Cell Sci. 2019 Jul 1;132(13):jcs228791. doi: 10.1242/jcs.228791.
Centrins are EF-hand containing proteins ubiquitously found in eukaryotes and are key components of centrioles/basal bodies as well as certain contractile fibers. We previously identified three centrins in the human parasite , all of which localized to the centrioles. However, one of them, (Tg) Centrin2 (CEN2), is also targeted to structures at the apical and basal ends of the parasite, as well as to annuli at the base of the apical cap of the membrane cortex. The role(s) that CEN2 play in these locations were unknown. Here, we report the functional characterization of CEN2 using a conditional knockdown method that combines transcriptional and protein stability control. The knockdown resulted in an ordered loss of CEN2 from its four compartments, due to differences in incorporation kinetics and structural inheritance over successive generations. This was correlated with a major invasion deficiency at early stages of knockdown, and replication defects at later stages. These results indicate that CEN2 is incorporated into multiple cytoskeletal structures to serve distinct functions that are required for parasite survival.
中心体是真核生物中普遍存在的 EF 手蛋白,是中心体/基体以及某些收缩纤维的关键组成部分。我们之前在人类寄生虫 中鉴定出三种中心体,它们都定位于中心体。然而,其中一种, (Tg) Centrin2 (CEN2),也被靶向到寄生虫的顶端和底部结构,以及膜皮质顶端帽基部的环。CEN2 在这些位置的作用尚不清楚。在这里,我们使用转录和蛋白质稳定性控制相结合的条件敲低方法来报告 CEN2 的功能特征。由于在连续几代中的掺入动力学和结构遗传的差异,敲低导致 CEN2 从其四个隔室有序丢失。这与早期 敲低时的主要入侵缺陷以及后期的复制缺陷相关。这些结果表明,CEN2 被整合到多个细胞骨架结构中,以发挥不同的功能,这些功能是寄生虫生存所必需的。