Organizational changes of the daughter basal complex during the parasite replication of Toxoplasma gondii.
Organizational changes of the daughter basal complex during the parasite replication of Toxoplasma gondii.
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DOI：
10.1371/journal.ppat.0040010
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发表时间：
2008-01
期刊：
影响因子：
6.7
通讯作者：
Hu K
中科院分区：
文献类型：
--
作者：
Hu K
尖端复合体是一大类寄生性原虫，其中许多是重要的人和动物病原体，包括恶性疟原虫和弓形虫。这些寄生虫只有在复制时才会致病，它们的复制严重依赖于寄生虫细胞分裂期间细胞骨架的正确组装。除了在发病机制中的重要性外，顶丛寄生虫的细胞骨架也是壮观的结构。因此，了解这些寄生虫的细胞骨架生物发生不仅对寄生虫学很重要，而且对更广泛的细胞生物学也有普遍的兴趣。此前，我们发现弓形虫的基端含有一种新的细胞骨架组件，即基底层复合体，即在细胞分裂过程中与子代皮质细胞骨架协同构建的细胞骨架间。这项研究利用高分辨率光学显微镜重点研究了基本复合体生物发生过程中的关键事件，并揭示了子体基本复合体是围绕复制的中心粒建立的，独立于子体皮质细胞骨架的结构完整性，并且它们是子体生长末端的动态“帽子”。在细胞分裂的后期，当一个含有钙结合蛋白的EF-Hand被招募时，基本复合体的区隔和极化第一次被揭示出来。这与基础复合体的收缩有关，这一过程可以通过增加细胞内钙浓度来人工诱导。因此，基础复合体很可能是一种新型的以中心素为基础的收缩装置。弓形虫是温血动物中最常见的寄生虫之一，也是人类的重要病原体。它是人类先天性神经缺陷的最常见原因，也会在免疫受损的患者中造成毁灭性的机会性感染。它在Apicomplexa门的5000个亲戚中，有许多也是重要的人类或动物病原体，包括每年导致100多万人死亡的疟原虫。这些寄生虫引起的疾病的发病机制完全取决于它们的复制能力，而复制能力又完全取决于寄生虫细胞骨架的正确组装。在这里，我探讨了在弓形虫的子细胞形成过程中，弓形虫基端包含的一种新的细胞骨架间隔--基底部复合体是如何组装的。我发现，女儿基复合体是弓形虫细胞分裂过程中组装的第一批细胞骨架结构之一。此外，基础复合体很可能是一种新的基于中心素的收缩装置，因为它的极化最初是在钙结合蛋白TgCentrin2的招募时揭示的，TgCentrin2与基础复合体的收缩有关，这一过程可以通过增加细胞内钙浓度来人工诱导。
The apicomplexans are a large group of parasitic protozoa, many of which are important human and animal pathogens, including Plasmodium falciparum and Toxoplasma gondii. These parasites cause disease only when they replicate, and their replication is critically dependent on the proper assembly of the parasite cytoskeletons during cell division. In addition to their importance in pathogenesis, the apicomplexan parasite cytoskeletons are spectacular structures. Therefore, understanding the cytoskeletal biogenesis of these parasites is important not only for parasitology but also of general interest to broader cell biology. Previously, we found that the basal end of T. gondii contains a novel cytoskeletal assembly, the basal complex, a cytoskeletal compartment constructed in concert with the daughter cortical cytoskeleton during cell division. This study focuses on key events during the biogenesis of the basal complex using high resolution light microscopy, and reveals that daughter basal complexes are established around the duplicated centrioles independently of the structural integrity of the daughter cortical cytoskeleton, and that they are dynamic “caps” at the growing ends of the daughters. Compartmentation and polarization of the basal complex is first revealed at a late stage of cell division upon the recruitment of an EF-hand containing calcium binding protein, TgCentrin2. This correlates with the constriction of the basal complex, a process that can be artificially induced by increasing cellular calcium concentration. The basal complex is therefore likely to be a new kind of centrin-based contractile apparatus. Toxoplasma gondii is one of the most prevalent parasites in warm-blooded animals and a highly important human pathogen. It is the most common cause of congenital neurological defects in humans and also causes devastating opportunistic infections in immuno-compromised patients. Many of its 5,000 relatives in phylum Apicomplexa are also important human or animal pathogens, including Plasmodium sps, which kill more than a million people every year. The pathogenesis of the diseases that these parasites cause absolutely depend on their ability to replicate, which in turn completely depends on the proper assembly of the parasite cytoskeletons. Here I probe how the basal complex, a novel cytoskeletal compartment contained within the basal end of T. gondii, is assembled during daughter cell formation of this parasite. I found that the daughter basal complex is one of the first cytoskeletal structures assembled during T. gondii cell division. In addition, the basal complex is likely to be a new kind of centrin-based contractile apparatus, as its polarization is first revealed upon the recruitment of a calcium binding protein, TgCentrin2, which correlates with the constriction of the basal complex, a process that can be artificially induced by increasing cellular calcium concentration.
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影响因子：
4
作者：
Hu, K;Roos, DS;Murray, JM
通讯作者：
Murray, JM
DOI：
10.4269/ajtmh.1966.15.449
发表时间：
1966-01-01
影响因子：
3.3
作者：
AIKAWA, M
通讯作者：
AIKAWA, M
影响因子：
1.3
作者：
SHEFFIELD, HG;MELTON, ML
通讯作者：
MELTON, ML
入侵机的细胞骨架成分 - 弓形虫弓形虫的顶端复合物。
影响因子：
6.7
作者：
Hu K;Johnson J;Florens L;Fraunholz M;Suravajjala S;DiLullo C;Yates J;Roos DS;Murray JM
通讯作者：
Murray JM
DOI：
10.1083/jcb.124.5.795
发表时间：
1994-03
期刊：
The Journal of cell biology
影响因子：
--
作者：
Sanders MA;Salisbury JL
通讯作者：
Salisbury JL