Cell cycle control of secondary endosymbionts

次级内共生体的细胞周期控制

• 批准号: 5373469
• 负责人: Professor Dr. Uwe Gallus Maier
• 金额: --
• 依托单位: Arbeitsgruppe Zellbiologie
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2002
• 资助国家: 德国
• 起止时间: 2001-12-31 至 2004-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5373469?language=en
• 关键词: Cell; cycle; control; secondary; endosymbionts

Cryptomonads evolved by the engulfment of a eukaryotic algal cell by a heterotrophic eukaryote. In the course of intracellular lifestyle, the symbionts are reduced to a multi-membrane bounded plastid (complex plastid). However, in comparison to other organisms with similar phylogenetic origin and complex plastids (e.g. the Apicomplexa), cryptomonads still contain the reduced nucleus of the eukaryotic symbiont, called the nucleomorph. The division of the nucleomorph preceeds those of the cell nucleus and is under the control of the host. In the course of our international nucleomorph genome project we have scanned the nucleomorph for genes encoding cell cycle factors. Thus, we are able to foresee which cell cycle components are supplemented by the host. These components are the molecular basis for the regulation of the symbiont´s cell cycle by the host. In our project we will isolate factors involved in the S- and G2-M- phases and characterize their topogenic signals as well as their regulation. This will offer for the first time the signals which are responsible for protein transport across the first two membranes of a complex plastid. As topogenic signals are markers for protein import into complex plastids, their knowledge will be used to identify proteins localized in the apicoplast membranes by screening the Apicomplexa databases.

隐藻是由真核藻类细胞被异养真核生物吞噬而进化而来的。在细胞内生活方式的过程中，共生体被还原成一个多膜结合的质体（复合质体）。然而，与其他具有相似系统发育起源和复杂质体的生物（例如顶复门）相比，隐单胞菌仍然含有真核共生体的还原核，称为核形物。核形的分裂先于细胞核的分裂，并受宿主的控制。在我们的国际核型基因组计划的过程中，我们已经扫描了编码细胞周期因子的基因的核型。因此，我们能够预见哪些细胞周期成分由宿主补充。这些成分是宿主调节共生体细胞周期的分子基础。在我们的项目中，我们将分离出参与S-和G2-M-阶段的因子，并表征其拓扑信号及其调节。这将首次提供负责蛋白质跨复杂质体的前两层膜运输的信号。由于拓扑信号是蛋白质输入到复杂质体的标记，它们的知识将用于通过筛选顶复体数据库来识别定位在顶质体膜中的蛋白质。